litmus-rt.git - The LITMUS^RT kernel.

diff options

Diffstat (limited to 'net/unix/garbage.c')

-rw-r--r--

1 files changed, 9 insertions, 9 deletions


diff --git a/net/unix/garbage.c b/net/unix/garbage.c index ebdff3d877a1..2a27b84f740b 100644 --- a/net/unix/garbage.c +++ b/net/unix/garbage.c
@@ -127,7 +127,7 @@ void unix_inflight(struct file *fp)
127	if(s) {	127	if(s) {
128	struct unix_sock *u = unix_sk(s);	128	struct unix_sock *u = unix_sk(s);
129	spin_lock(&unix_gc_lock);	129	spin_lock(&unix_gc_lock);
130	if (atomic_inc_return(&u->inflight) == 1) {	130	if (atomic_long_inc_return(&u->inflight) == 1) {
131	BUG_ON(!list_empty(&u->link));	131	BUG_ON(!list_empty(&u->link));
132	list_add_tail(&u->link, &gc_inflight_list);	132	list_add_tail(&u->link, &gc_inflight_list);
133	} else {	133	} else {
@@ -145,7 +145,7 @@ void unix_notinflight(struct file *fp)
145	struct unix_sock *u = unix_sk(s);	145	struct unix_sock *u = unix_sk(s);
146	spin_lock(&unix_gc_lock);	146	spin_lock(&unix_gc_lock);
147	BUG_ON(list_empty(&u->link));	147	BUG_ON(list_empty(&u->link));
148	if (atomic_dec_and_test(&u->inflight))	148	if (atomic_long_dec_and_test(&u->inflight))
149	list_del_init(&u->link);	149	list_del_init(&u->link);
150	unix_tot_inflight--;	150	unix_tot_inflight--;
151	spin_unlock(&unix_gc_lock);	151	spin_unlock(&unix_gc_lock);
@@ -237,17 +237,17 @@ static void scan_children(struct sock x, void (func)(struct unix_sock *),
237		237
238	static void dec_inflight(struct unix_sock *usk)	238	static void dec_inflight(struct unix_sock *usk)
239	{	239	{
240	atomic_dec(&usk->inflight);	240	atomic_long_dec(&usk->inflight);
241	}	241	}
242		242
243	static void inc_inflight(struct unix_sock *usk)	243	static void inc_inflight(struct unix_sock *usk)
244	{	244	{
245	atomic_inc(&usk->inflight);	245	atomic_long_inc(&usk->inflight);
246	}	246	}
247		247
248	static void inc_inflight_move_tail(struct unix_sock *u)	248	static void inc_inflight_move_tail(struct unix_sock *u)
249	{	249	{
250	atomic_inc(&u->inflight);	250	atomic_long_inc(&u->inflight);
251	/*	251	/*
252	* If this is still a candidate, move it to the end of the	252	* If this is still a candidate, move it to the end of the
253	* list, so that it's checked even if it was already passed	253	* list, so that it's checked even if it was already passed
@@ -288,11 +288,11 @@ void unix_gc(void)
288	* before the detach without atomicity guarantees.	288	* before the detach without atomicity guarantees.
289	*/	289	*/
290	list_for_each_entry_safe(u, next, &gc_inflight_list, link) {	290	list_for_each_entry_safe(u, next, &gc_inflight_list, link) {
291	int total_refs;	291	long total_refs;
292	int inflight_refs;	292	long inflight_refs;
293		293
294	total_refs = file_count(u->sk.sk_socket->file);	294	total_refs = file_count(u->sk.sk_socket->file);
295	inflight_refs = atomic_read(&u->inflight);	295	inflight_refs = atomic_long_read(&u->inflight);
296		296
297	BUG_ON(inflight_refs < 1);	297	BUG_ON(inflight_refs < 1);
298	BUG_ON(total_refs < inflight_refs);	298	BUG_ON(total_refs < inflight_refs);
@@ -324,7 +324,7 @@ void unix_gc(void)
324	/* Move cursor to after the current position. */	324	/* Move cursor to after the current position. */
325	list_move(&cursor, &u->link);	325	list_move(&cursor, &u->link);
326		326
327	if (atomic_read(&u->inflight) > 0) {	327	if (atomic_long_read(&u->inflight) > 0) {
328	list_move_tail(&u->link, &gc_inflight_list);	328	list_move_tail(&u->link, &gc_inflight_list);
329	u->gc_candidate = 0;	329	u->gc_candidate = 0;
330	scan_children(&u->sk, inc_inflight_move_tail, NULL);	330	scan_children(&u->sk, inc_inflight_move_tail, NULL);

/* * INET An implementation of the TCP/IP protocol suite for the LINUX * operating system. INET is implemented using the BSD Socket * interface as the means of communication with the user level. * * PACKET - implements raw packet sockets. * * Authors: Ross Biro * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> * Alan Cox, <gw4pts@gw4pts.ampr.org> * * Fixes: * Alan Cox : verify_area() now used correctly * Alan Cox : new skbuff lists, look ma no backlogs! * Alan Cox : tidied skbuff lists. * Alan Cox : Now uses generic datagram routines I * added. Also fixed the peek/read crash * from all old Linux datagram code. * Alan Cox : Uses the improved datagram code. * Alan Cox : Added NULL's for socket options. * Alan Cox : Re-commented the code. * Alan Cox : Use new kernel side addressing * Rob Janssen : Correct MTU usage. * Dave Platt : Counter leaks caused by incorrect * interrupt locking and some slightly * dubious gcc output. Can you read * compiler: it said _VOLATILE_ * Richard Kooijman : Timestamp fixes. * Alan Cox : New buffers. Use sk->mac.raw. * Alan Cox : sendmsg/recvmsg support. * Alan Cox : Protocol setting support * Alexey Kuznetsov : Untied from IPv4 stack. * Cyrus Durgin : Fixed kerneld for kmod. * Michal Ostrowski : Module initialization cleanup. * Ulises Alonso : Frame number limit removal and * packet_set_ring memory leak. * Eric Biederman : Allow for > 8 byte hardware addresses. * The convention is that longer addresses * will simply extend the hardware address * byte arrays at the end of sockaddr_ll * and packet_mreq. * Johann Baudy : Added TX RING. * Chetan Loke : Implemented TPACKET_V3 block abstraction * layer. * Copyright (C) 2011, <lokec@ccs.neu.edu> * * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version * 2 of the License, or (at your option) any later version. * */ #include <linux/types.h> #include <linux/mm.h> #include <linux/capability.h> #include <linux/fcntl.h> #include <linux/socket.h> #include <linux/in.h> #include <linux/inet.h> #include <linux/netdevice.h> #include <linux/if_packet.h> #include <linux/wireless.h> #include <linux/kernel.h> #include <linux/kmod.h> #include <linux/slab.h> #include <linux/vmalloc.h> #include <net/net_namespace.h> #include <net/ip.h> #include <net/protocol.h> #include <linux/skbuff.h> #include <net/sock.h> #include <linux/errno.h> #include <linux/timer.h> #include <asm/uaccess.h> #include <asm/ioctls.h> #include <asm/page.h> #include <asm/cacheflush.h> #include <asm/io.h> #include <linux/proc_fs.h> #include <linux/seq_file.h> #include <linux/poll.h> #include <linux/module.h> #include <linux/init.h> #include <linux/mutex.h> #include <linux/if_vlan.h> #include <linux/virtio_net.h> #include <linux/errqueue.h> #include <linux/net_tstamp.h> #ifdef CONFIG_INET #include <net/inet_common.h> #endif /* Assumptions: - if device has no dev->hard_header routine, it adds and removes ll header inside itself. In this case ll header is invisible outside of device, but higher levels still should reserve dev->hard_header_len. Some devices are enough clever to reallocate skb, when header will not fit to reserved space (tunnel), another ones are silly (PPP). - packet socket receives packets with pulled ll header, so that SOCK_RAW should push it back. On receive: ----------- Incoming, dev->hard_header!=NULL mac_header -> ll header data -> data Outgoing, dev->hard_header!=NULL mac_header -> ll header data -> ll header Incoming, dev->hard_header==NULL mac_header -> UNKNOWN position. It is very likely, that it points to ll header. PPP makes it, that is wrong, because introduce assymetry between rx and tx paths. data -> data Outgoing, dev->hard_header==NULL mac_header -> data. ll header is still not built! data -> data Resume If dev->hard_header==NULL we are unlikely to restore sensible ll header. On transmit: ------------ dev->hard_header != NULL mac_header -> ll header data -> ll header dev->hard_header == NULL (ll header is added by device, we cannot control it) mac_header -> data data -> data We should set nh.raw on output to correct posistion, packet classifier depends on it. */ /* Private packet socket structures. */ struct packet_mclist { struct packet_mclist *next; int ifindex; int count; unsigned short type; unsigned short alen; unsigned char addr[MAX_ADDR_LEN]; }; /* identical to struct packet_mreq except it has * a longer address field. */ struct packet_mreq_max { int mr_ifindex; unsigned short mr_type; unsigned short mr_alen; unsigned char mr_address[MAX_ADDR_LEN]; }; static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u, int closing, int tx_ring); #define V3_ALIGNMENT (8) #define BLK_HDR_LEN (ALIGN(sizeof(struct tpacket_block_desc), V3_ALIGNMENT)) #define BLK_PLUS_PRIV(sz_of_priv) \ (BLK_HDR_LEN + ALIGN((sz_of_priv), V3_ALIGNMENT)) /* kbdq - kernel block descriptor queue */ struct tpacket_kbdq_core { struct pgv *pkbdq; unsigned int feature_req_word; unsigned int hdrlen; unsigned char reset_pending_on_curr_blk; unsigned char delete_blk_timer; unsigned short kactive_blk_num; unsigned short blk_sizeof_priv; /* last_kactive_blk_num: * trick to see if user-space has caught up * in order to avoid refreshing timer when every single pkt arrives. */ unsigned short last_kactive_blk_num; char *pkblk_start; char *pkblk_end; int kblk_size; unsigned int knum_blocks; uint64_t knxt_seq_num; char *prev; char *nxt_offset; struct sk_buff *skb; atomic_t blk_fill_in_prog; /* Default is set to 8ms */ #define DEFAULT_PRB_RETIRE_TOV (8) unsigned short retire_blk_tov; unsigned short version; unsigned long tov_in_jiffies; /* timer to retire an outstanding block */ struct timer_list retire_blk_timer; }; #define PGV_FROM_VMALLOC 1 struct pgv { char *buffer; }; struct packet_ring_buffer { struct pgv *pg_vec; unsigned int head; unsigned int frames_per_block; unsigned int frame_size; unsigned int frame_max; unsigned int pg_vec_order; unsigned int pg_vec_pages; unsigned int pg_vec_len; struct tpacket_kbdq_core prb_bdqc; atomic_t pending; }; #define BLOCK_STATUS(x) ((x)->hdr.bh1.block_status) #define BLOCK_NUM_PKTS(x) ((x)->hdr.bh1.num_pkts) #define BLOCK_O2FP(x) ((x)->hdr.bh1.offset_to_first_pkt) #define BLOCK_LEN(x) ((x)->hdr.bh1.blk_len) #define BLOCK_SNUM(x) ((x)->hdr.bh1.seq_num) #define BLOCK_O2PRIV(x) ((x)->offset_to_priv) #define BLOCK_PRIV(x) ((void *)((char *)(x) + BLOCK_O2PRIV(x))) struct packet_sock; static int tpacket_snd(struct packet_sock *po, struct msghdr *msg); static void *packet_previous_frame(struct packet_sock *po, struct packet_ring_buffer *rb, int status); static void packet_increment_head(struct packet_ring_buffer *buff); static int prb_curr_blk_in_use(struct tpacket_kbdq_core *, struct tpacket_block_desc *); static void *prb_dispatch_next_block(struct tpacket_kbdq_core *, struct packet_sock *); static void prb_retire_current_block(struct tpacket_kbdq_core *, struct packet_sock *, unsigned int status); static int prb_queue_frozen(struct tpacket_kbdq_core *); static void prb_open_block(struct tpacket_kbdq_core *, struct tpacket_block_desc *); static void prb_retire_rx_blk_timer_expired(unsigned long); static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *); static void prb_init_blk_timer(struct packet_sock *, struct tpacket_kbdq_core *, void (*func) (unsigned long)); static void prb_fill_rxhash(struct tpacket_kbdq_core *, struct tpacket3_hdr *); static void prb_clear_rxhash(struct tpacket_kbdq_core *, struct tpacket3_hdr *); static void prb_fill_vlan_info(struct tpacket_kbdq_core *, struct tpacket3_hdr *); static void packet_flush_mclist(struct sock *sk); struct packet_fanout; struct packet_sock { /* struct sock has to be the first member of packet_sock */ struct sock sk; struct packet_fanout *fanout; struct tpacket_stats stats; union tpacket_stats_u stats_u; struct packet_ring_buffer rx_ring; struct packet_ring_buffer tx_ring; int copy_thresh; spinlock_t bind_lock; struct mutex pg_vec_lock; unsigned int running:1, /* prot_hook is attached*/ auxdata:1, origdev:1, has_vnet_hdr:1; int ifindex; /* bound device */ __be16 num; struct packet_mclist *mclist; atomic_t mapped; enum tpacket_versions tp_version; unsigned int tp_hdrlen; unsigned int tp_reserve; unsigned int tp_loss:1; unsigned int tp_tstamp; struct packet_type prot_hook ____cacheline_aligned_in_smp; }; #define PACKET_FANOUT_MAX 256 struct packet_fanout { #ifdef CONFIG_NET_NS struct net *net; #endif unsigned int num_members; u16 id; u8 type; u8 defrag; atomic_t rr_cur; struct list_head list; struct sock *arr[PACKET_FANOUT_MAX]; spinlock_t lock; atomic_t sk_ref; struct packet_type prot_hook ____cacheline_aligned_in_smp; }; struct packet_skb_cb { unsigned int origlen; union { struct sockaddr_pkt pkt; struct sockaddr_ll ll; } sa; }; #define PACKET_SKB_CB(__skb) ((struct packet_skb_cb *)((__skb)->cb)) #define GET_PBDQC_FROM_RB(x) ((struct tpacket_kbdq_core *)(&(x)->prb_bdqc)) #define GET_PBLOCK_DESC(x, bid) \ ((struct tpacket_block_desc *)((x)->pkbdq[(bid)].buffer)) #define GET_CURR_PBLOCK_DESC_FROM_CORE(x) \ ((struct tpacket_block_desc *)((x)->pkbdq[(x)->kactive_blk_num].buffer)) #define GET_NEXT_PRB_BLK_NUM(x) \ (((x)->kactive_blk_num < ((x)->knum_blocks-1)) ? \ ((x)->kactive_blk_num+1) : 0) static struct packet_sock *pkt_sk(struct sock *sk) { return (struct packet_sock *)sk; } static void __fanout_unlink(struct sock *sk, struct packet_sock *po); static void __fanout_link(struct sock *sk, struct packet_sock *po); /* register_prot_hook must be invoked with the po->bind_lock held, * or from a context in which asynchronous accesses to the packet * socket is not possible (packet_create()). */ static void register_prot_hook(struct sock *sk) { struct packet_sock *po = pkt_sk(sk); if (!po->running) { if (po->fanout) __fanout_link(sk, po); else dev_add_pack(&po->prot_hook); sock_hold(sk); po->running = 1; } } /* {,__}unregister_prot_hook() must be invoked with the po->bind_lock * held. If the sync parameter is true, we will temporarily drop * the po->bind_lock and do a synchronize_net to make sure no * asynchronous packet processing paths still refer to the elements * of po->prot_hook. If the sync parameter is false, it is the * callers responsibility to take care of this. */ static void __unregister_prot_hook(struct sock *sk, bool sync) { struct packet_sock *po = pkt_sk(sk); po->running = 0; if (po->fanout) __fanout_unlink(sk, po); else __dev_remove_pack(&po->prot_hook); __sock_put(sk); if (sync) { spin_unlock(&po->bind_lock); synchronize_net(); spin_lock(&po->bind_lock); } } static void unregister_prot_hook(struct sock *sk, bool sync) { struct packet_sock *po = pkt_sk(sk); if (po->running) __unregister_prot_hook(sk, sync); } static inline __pure struct page *pgv_to_page(void *addr) { if (is_vmalloc_addr(addr)) return vmalloc_to_page(addr); return virt_to_page(addr); } static void __packet_set_status(struct packet_sock *po, void *frame, int status) { union { struct tpacket_hdr *h1; struct tpacket2_hdr *h2; void *raw; } h; h.raw = frame; switch (po->tp_version) { case TPACKET_V1: h.h1->tp_status = status; flush_dcache_page(pgv_to_page(&h.h1->tp_status)); break; case TPACKET_V2: h.h2->tp_status = status; flush_dcache_page(pgv_to_page(&h.h2->tp_status)); break; case TPACKET_V3: default: WARN(1, "TPACKET version not supported.\n"); BUG(); } smp_wmb(); } static int __packet_get_status(struct packet_sock *po, void *frame) { union { struct tpacket_hdr *h1; struct tpacket2_hdr *h2; void *raw; } h; smp_rmb(); h.raw = frame; switch (po->tp_version) { case TPACKET_V1: flush_dcache_page(pgv_to_page(&h.h1->tp_status)); return h.h1->tp_status; case TPACKET_V2: flush_dcache_page(pgv_to_page(&h.h2->tp_status)); return h.h2->tp_status; case TPACKET_V3: default: WARN(1, "TPACKET version not supported.\n"); BUG(); return 0; } } static void *packet_lookup_frame(struct packet_sock *po, struct packet_ring_buffer *rb, unsigned int position, int status) { unsigned int pg_vec_pos, frame_offset; union { struct tpacket_hdr *h1; struct tpacket2_hdr *h2; void *raw; } h; pg_vec_pos = position / rb->frames_per_block; frame_offset = position % rb->frames_per_block; h.raw = rb->pg_vec[pg_vec_pos].buffer + (frame_offset * rb->frame_size); if (status != __packet_get_status(po, h.raw)) return NULL; return h.raw; } static void *packet_current_frame(struct packet_sock *po, struct packet_ring_buffer *rb, int status) { return packet_lookup_frame(po, rb, rb->head, status); } static void prb_del_retire_blk_timer(struct tpacket_kbdq_core *pkc) { del_timer_sync(&pkc->retire_blk_timer); } static void prb_shutdown_retire_blk_timer(struct packet_sock *po, int tx_ring, struct sk_buff_head *rb_queue) { struct tpacket_kbdq_core *pkc; pkc = tx_ring ? &po->tx_ring.prb_bdqc : &po->rx_ring.prb_bdqc; spin_lock(&rb_queue->lock); pkc->delete_blk_timer = 1; spin_unlock(&rb_queue->lock); prb_del_retire_blk_timer(pkc); } static void prb_init_blk_timer(struct packet_sock *po, struct tpacket_kbdq_core *pkc, void (*func) (unsigned long)) { init_timer(&pkc->retire_blk_timer); pkc->retire_blk_timer.data = (long)po; pkc->retire_blk_timer.function = func; pkc->retire_blk_timer.expires = jiffies; } static void prb_setup_retire_blk_timer(struct packet_sock *po, int tx_ring) { struct tpacket_kbdq_core *pkc; if (tx_ring) BUG(); pkc = tx_ring ? &po->tx_ring.prb_bdqc : &po->rx_ring.prb_bdqc; prb_init_blk_timer(po, pkc, prb_retire_rx_blk_timer_expired); } static int prb_calc_retire_blk_tmo(struct packet_sock *po, int blk_size_in_bytes) { struct net_device *dev; unsigned int mbits = 0, msec = 0, div = 0, tmo = 0; struct ethtool_cmd ecmd; int err; u32 speed; rtnl_lock(); dev = __dev_get_by_index(sock_net(&po->sk), po->ifindex); if (unlikely(!dev)) { rtnl_unlock(); return DEFAULT_PRB_RETIRE_TOV; } err = __ethtool_get_settings(dev, &ecmd); speed = ethtool_cmd_speed(&ecmd); rtnl_unlock(); if (!err) { /* * If the link speed is so slow you don't really * need to worry about perf anyways */ if (speed < SPEED_1000 || speed == SPEED_UNKNOWN) { return DEFAULT_PRB_RETIRE_TOV; } else { msec = 1; div = speed / 1000; } } mbits = (blk_size_in_bytes * 8) / (1024 * 1024); if (div) mbits /= div; tmo = mbits * msec; if (div) return tmo+1; return tmo; } static void prb_init_ft_ops(struct tpacket_kbdq_core *p1, union tpacket_req_u *req_u) { p1->feature_req_word = req_u->req3.tp_feature_req_word; } static void init_prb_bdqc(struct packet_sock *po, struct packet_ring_buffer *rb, struct pgv *pg_vec, union tpacket_req_u *req_u, int tx_ring) { struct tpacket_kbdq_core *p1 = &rb->prb_bdqc; struct tpacket_block_desc *pbd; memset(p1, 0x0, sizeof(*p1)); p1->knxt_seq_num = 1; p1->pkbdq = pg_vec; pbd = (struct tpacket_block_desc *)pg_vec[0].buffer; p1->pkblk_start = pg_vec[0].buffer; p1->kblk_size = req_u->req3.tp_block_size; p1->knum_blocks = req_u->req3.tp_block_nr; p1->hdrlen = po->tp_hdrlen; p1->version = po->tp_version; p1->last_kactive_blk_num = 0; po->stats_u.stats3.tp_freeze_q_cnt = 0; if (req_u->req3.tp_retire_blk_tov) p1->retire_blk_tov = req_u->req3.tp_retire_blk_tov; else p1->retire_blk_tov = prb_calc_retire_blk_tmo(po, req_u->req3.tp_block_size); p1->tov_in_jiffies = msecs_to_jiffies(p1->retire_blk_tov); p1->blk_sizeof_priv = req_u->req3.tp_sizeof_priv; prb_init_ft_ops(p1, req_u); prb_setup_retire_blk_timer(po, tx_ring); prb_open_block(p1, pbd); } /* Do NOT update the last_blk_num first. * Assumes sk_buff_head lock is held. */ static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *pkc) { mod_timer(&pkc->retire_blk_timer, jiffies + pkc->tov_in_jiffies); pkc->last_kactive_blk_num = pkc->kactive_blk_num; } /* * Timer logic: * 1) We refresh the timer only when we open a block. * By doing this we don't waste cycles refreshing the timer * on packet-by-packet basis. * * With a 1MB block-size, on a 1Gbps line, it will take * i) ~8 ms to fill a block + ii) memcpy etc. * In this cut we are not accounting for the memcpy time. * * So, if the user sets the 'tmo' to 10ms then the timer * will never fire while the block is still getting filled * (which is what we want). However, the user could choose * to close a block early and that's fine. * * But when the timer does fire, we check whether or not to refresh it. * Since the tmo granularity is in msecs, it is not too expensive * to refresh the timer, lets say every '8' msecs. * Either the user can set the 'tmo' or we can derive it based on * a) line-speed and b) block-size. * prb_calc_retire_blk_tmo() calculates the tmo. * */ static void prb_retire_rx_blk_timer_expired(unsigned long data) { struct packet_sock *po = (struct packet_sock *)data; struct tpacket_kbdq_core *pkc = &po->rx_ring.prb_bdqc; unsigned int frozen; struct tpacket_block_desc *pbd; spin_lock(&po->sk.sk_receive_queue.lock); frozen = prb_queue_frozen(pkc); pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); if (unlikely(pkc->delete_blk_timer)) goto out; /* We only need to plug the race when the block is partially filled. * tpacket_rcv: * lock(); increment BLOCK_NUM_PKTS; unlock() * copy_bits() is in progress ... * timer fires on other cpu: * we can't retire the current block because copy_bits * is in progress. * */ if (BLOCK_NUM_PKTS(pbd)) { while (atomic_read(&pkc->blk_fill_in_prog)) { /* Waiting for skb_copy_bits to finish... */ cpu_relax(); } } if (pkc->last_kactive_blk_num == pkc->kactive_blk_num) { if (!frozen) { prb_retire_current_block(pkc, po, TP_STATUS_BLK_TMO); if (!prb_dispatch_next_block(pkc, po)) goto refresh_timer; else goto out; } else { /* Case 1. Queue was frozen because user-space was * lagging behind. */ if (prb_curr_blk_in_use(pkc, pbd)) { /* * Ok, user-space is still behind. * So just refresh the timer. */ goto refresh_timer; } else { /* Case 2. queue was frozen,user-space caught up, * now the link went idle && the timer fired. * We don't have a block to close.So we open this * block and restart the timer. * opening a block thaws the queue,restarts timer * Thawing/timer-refresh is a side effect. */ prb_open_block(pkc, pbd); goto out; } } } refresh_timer: _prb_refresh_rx_retire_blk_timer(pkc); out: spin_unlock(&po->sk.sk_receive_queue.lock); } static void prb_flush_block(struct tpacket_kbdq_core *pkc1, struct tpacket_block_desc *pbd1, __u32 status) { /* Flush everything minus the block header */ #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1 u8 *start, *end; start = (u8 *)pbd1; /* Skip the block header(we know header WILL fit in 4K) */ start += PAGE_SIZE; end = (u8 *)PAGE_ALIGN((unsigned long)pkc1->pkblk_end); for (; start < end; start += PAGE_SIZE) flush_dcache_page(pgv_to_page(start)); smp_wmb(); #endif /* Now update the block status. */ BLOCK_STATUS(pbd1) = status; /* Flush the block header */ #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1 start = (u8 *)pbd1; flush_dcache_page(pgv_to_page(start)); smp_wmb(); #endif } /* * Side effect: * * 1) flush the block * 2) Increment active_blk_num * * Note:We DONT refresh the timer on purpose. * Because almost always the next block will be opened. */ static void prb_close_block(struct tpacket_kbdq_core *pkc1, struct tpacket_block_desc *pbd1, struct packet_sock *po, unsigned int stat) { __u32 status = TP_STATUS_USER | stat; struct tpacket3_hdr *last_pkt; struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1; if (po->stats.tp_drops) status |= TP_STATUS_LOSING; last_pkt = (struct tpacket3_hdr *)pkc1->prev; last_pkt->tp_next_offset = 0; /* Get the ts of the last pkt */ if (BLOCK_NUM_PKTS(pbd1)) { h1->ts_last_pkt.ts_sec = last_pkt->tp_sec; h1->ts_last_pkt.ts_nsec = last_pkt->tp_nsec; } else { /* Ok, we tmo'd - so get the current time */ struct timespec ts; getnstimeofday(&ts); h1->ts_last_pkt.ts_sec = ts.tv_sec; h1->ts_last_pkt.ts_nsec = ts.tv_nsec; } smp_wmb(); /* Flush the block */ prb_flush_block(pkc1, pbd1, status); pkc1->kactive_blk_num = GET_NEXT_PRB_BLK_NUM(pkc1); } static void prb_thaw_queue(struct tpacket_kbdq_core *pkc) { pkc->reset_pending_on_curr_blk = 0; } /* * Side effect of opening a block: * * 1) prb_queue is thawed. * 2) retire_blk_timer is refreshed. * */ static void prb_open_block(struct tpacket_kbdq_core *pkc1, struct tpacket_block_desc *pbd1) { struct timespec ts; struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1; smp_rmb(); if (likely(TP_STATUS_KERNEL == BLOCK_STATUS(pbd1))) { /* We could have just memset this but we will lose the * flexibility of making the priv area sticky */ BLOCK_SNUM(pbd1) = pkc1->knxt_seq_num++; BLOCK_NUM_PKTS(pbd1) = 0; BLOCK_LEN(pbd1) = BLK_PLUS_PRIV(pkc1->blk_sizeof_priv); getnstimeofday(&ts); h1->ts_first_pkt.ts_sec = ts.tv_sec; h1->ts_first_pkt.ts_nsec = ts.tv_nsec; pkc1->pkblk_start = (char *)pbd1; pkc1->nxt_offset = pkc1->pkblk_start + BLK_PLUS_PRIV(pkc1->blk_sizeof_priv); BLOCK_O2FP(pbd1) = (__u32)BLK_PLUS_PRIV(pkc1->blk_sizeof_priv); BLOCK_O2PRIV(pbd1) = BLK_HDR_LEN; pbd1->version = pkc1->version; pkc1->prev = pkc1->nxt_offset; pkc1->pkblk_end = pkc1->pkblk_start + pkc1->kblk_size; prb_thaw_queue(pkc1); _prb_refresh_rx_retire_blk_timer(pkc1); smp_wmb(); return; } WARN(1, "ERROR block:%p is NOT FREE status:%d kactive_blk_num:%d\n", pbd1, BLOCK_STATUS(pbd1), pkc1->kactive_blk_num); dump_stack(); BUG(); } /* * Queue freeze logic: * 1) Assume tp_block_nr = 8 blocks. * 2) At time 't0', user opens Rx ring. * 3) Some time past 't0', kernel starts filling blocks starting from 0 .. 7 * 4) user-space is either sleeping or processing block '0'. * 5) tpacket_rcv is currently filling block '7', since there is no space left, * it will close block-7,loop around and try to fill block '0'. * call-flow: * __packet_lookup_frame_in_block * prb_retire_current_block() * prb_dispatch_next_block() * |->(BLOCK_STATUS == USER) evaluates to true * 5.1) Since block-0 is currently in-use, we just freeze the queue. * 6) Now there are two cases: * 6.1) Link goes idle right after the queue is frozen. * But remember, the last open_block() refreshed the timer. * When this timer expires,it will refresh itself so that we can * re-open block-0 in near future. * 6.2) Link is busy and keeps on receiving packets. This is a simple * case and __packet_lookup_frame_in_block will check if block-0 * is free and can now be re-used. */ static void prb_freeze_queue(struct tpacket_kbdq_core *pkc, struct packet_sock *po) { pkc->reset_pending_on_curr_blk = 1; po->stats_u.stats3.tp_freeze_q_cnt++; } #define TOTAL_PKT_LEN_INCL_ALIGN(length) (ALIGN((length), V3_ALIGNMENT)) /* * If the next block is free then we will dispatch it * and return a good offset. * Else, we will freeze the queue. * So, caller must check the return value. */ static void *prb_dispatch_next_block(struct tpacket_kbdq_core *pkc, struct packet_sock *po) { struct tpacket_block_desc *pbd; smp_rmb(); /* 1. Get current block num */ pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); /* 2. If this block is currently in_use then freeze the queue */ if (TP_STATUS_USER & BLOCK_STATUS(pbd)) { prb_freeze_queue(pkc, po); return NULL; } /* * 3. * open this block and return the offset where the first packet * needs to get stored. */ prb_open_block(pkc, pbd); return (void *)pkc->nxt_offset; } static void prb_retire_current_block(struct tpacket_kbdq_core *pkc, struct packet_sock *po, unsigned int status) { struct tpacket_block_desc *pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); /* retire/close the current block */ if (likely(TP_STATUS_KERNEL == BLOCK_STATUS(pbd))) { /* * Plug the case where copy_bits() is in progress on * cpu-0 and tpacket_rcv() got invoked on cpu-1, didn't * have space to copy the pkt in the current block and * called prb_retire_current_block() * * We don't need to worry about the TMO case because * the timer-handler already handled this case. */ if (!(status & TP_STATUS_BLK_TMO)) { while (atomic_read(&pkc->blk_fill_in_prog)) { /* Waiting for skb_copy_bits to finish... */ cpu_relax(); } } prb_close_block(pkc, pbd, po, status); return; } WARN(1, "ERROR-pbd[%d]:%p\n", pkc->kactive_blk_num, pbd); dump_stack(); BUG(); } static int prb_curr_blk_in_use(struct tpacket_kbdq_core *pkc, struct tpacket_block_desc *pbd) { return TP_STATUS_USER & BLOCK_STATUS(pbd); } static int prb_queue_frozen(struct tpacket_kbdq_core *pkc) { return pkc->reset_pending_on_curr_blk; } static void prb_clear_blk_fill_status(struct packet_ring_buffer *rb) { struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb); atomic_dec(&pkc->blk_fill_in_prog); } static void prb_fill_rxhash(struct tpacket_kbdq_core *pkc, struct tpacket3_hdr *ppd) { ppd->hv1.tp_rxhash = skb_get_rxhash(pkc->skb); } static void prb_clear_rxhash(struct tpacket_kbdq_core *pkc, struct tpacket3_hdr *ppd) { ppd->hv1.tp_rxhash = 0; } static void prb_fill_vlan_info(struct tpacket_kbdq_core *pkc, struct tpacket3_hdr *ppd) { if (vlan_tx_tag_present(pkc->skb)) { ppd->hv1.tp_vlan_tci = vlan_tx_tag_get(pkc->skb); ppd->tp_status = TP_STATUS_VLAN_VALID; } else { ppd->hv1.tp_vlan_tci = ppd->tp_status = 0; } } static void prb_run_all_ft_ops(struct tpacket_kbdq_core *pkc, struct tpacket3_hdr *ppd) { prb_fill_vlan_info(pkc, ppd); if (pkc->feature_req_word & TP_FT_REQ_FILL_RXHASH) prb_fill_rxhash(pkc, ppd); else prb_clear_rxhash(pkc, ppd); } static void prb_fill_curr_block(char *curr, struct tpacket_kbdq_core *pkc, struct tpacket_block_desc *pbd, unsigned int len) { struct tpacket3_hdr *ppd; ppd = (struct tpacket3_hdr *)curr; ppd->tp_next_offset = TOTAL_PKT_LEN_INCL_ALIGN(len); pkc->prev = curr; pkc->nxt_offset += TOTAL_PKT_LEN_INCL_ALIGN(len); BLOCK_LEN(pbd) += TOTAL_PKT_LEN_INCL_ALIGN(len); BLOCK_NUM_PKTS(pbd) += 1; atomic_inc(&pkc->blk_fill_in_prog); prb_run_all_ft_ops(pkc, ppd); } /* Assumes caller has the sk->rx_queue.lock */ static void *__packet_lookup_frame_in_block(struct packet_sock *po, struct sk_buff *skb, int status, unsigned int len ) { struct tpacket_kbdq_core *pkc; struct tpacket_block_desc *pbd; char *curr, *end; pkc = GET_PBDQC_FROM_RB(&po->rx_ring); pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); /* Queue is frozen when user space is lagging behind */ if (prb_queue_frozen(pkc)) { /* * Check if that last block which caused the queue to freeze, * is still in_use by user-space. */ if (prb_curr_blk_in_use(pkc, pbd)) { /* Can't record this packet */ return NULL; } else { /* * Ok, the block was released by user-space. * Now let's open that block. * opening a block also thaws the queue. * Thawing is a side effect. */ prb_open_block(pkc, pbd); } } smp_mb(); curr = pkc->nxt_offset; pkc->skb = skb; end = (char *)pbd + pkc->kblk_size; /* first try the current block */ if (curr+TOTAL_PKT_LEN_INCL_ALIGN(len) < end) { prb_fill_curr_block(curr, pkc, pbd, len); return (void *)curr; } /* Ok, close the current block */ prb_retire_current_block(pkc, po, 0); /* Now, try to dispatch the next block */ curr = (char *)prb_dispatch_next_block(pkc, po); if (curr) { pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); prb_fill_curr_block(curr, pkc, pbd, len); return (void *)curr; } /* * No free blocks are available.user_space hasn't caught up yet. * Queue was just frozen and now this packet will get dropped. */ return NULL; } static void *packet_current_rx_frame(struct packet_sock *po, struct sk_buff *skb, int status, unsigned int len) { char *curr = NULL; switch (po->tp_version) { case TPACKET_V1: case TPACKET_V2: curr = packet_lookup_frame(po, &po->rx_ring, po->rx_ring.head, status); return curr; case TPACKET_V3: return __packet_lookup_frame_in_block(po, skb, status, len); default: WARN(1, "TPACKET version not supported\n"); BUG(); return 0; } } static void *prb_lookup_block(struct packet_sock *po, struct packet_ring_buffer *rb, unsigned int previous, int status) { struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb); struct tpacket_block_desc *pbd = GET_PBLOCK_DESC(pkc, previous); if (status != BLOCK_STATUS(pbd)) return NULL; return pbd; } static int prb_previous_blk_num(struct packet_ring_buffer *rb) { unsigned int prev; if (rb->prb_bdqc.kactive_blk_num) prev = rb->prb_bdqc.kactive_blk_num-1; else prev = rb->prb_bdqc.knum_blocks-1; return prev; } /* Assumes caller has held the rx_queue.lock */ static void *__prb_previous_block(struct packet_sock *po, struct packet_ring_buffer *rb, int status) { unsigned int previous = prb_previous_blk_num(rb); return prb_lookup_block(po, rb, previous, status); } static void *packet_previous_rx_frame(struct packet_sock *po, struct packet_ring_buffer *rb, int status) { if (po->tp_version <= TPACKET_V2) return packet_previous_frame(po, rb, status); return __prb_previous_block(po, rb, status); } static void packet_increment_rx_head(struct packet_sock *po, struct packet_ring_buffer *rb) { switch (po->tp_version) { case TPACKET_V1: case TPACKET_V2: return packet_increment_head(rb); case TPACKET_V3: default: WARN(1, "TPACKET version not supported.\n"); BUG(); return; } } static void *packet_previous_frame(struct packet_sock *po, struct packet_ring_buffer *rb, int status) { unsigned int previous = rb->head ? rb->head - 1 : rb->frame_max; return packet_lookup_frame(po, rb, previous, status); } static void packet_increment_head(struct packet_ring_buffer *buff) { buff->head = buff->head != buff->frame_max ? buff->head+1 : 0; } static void packet_sock_destruct(struct sock *sk) { skb_queue_purge(&sk->sk_error_queue); WARN_ON(atomic_read(&sk->sk_rmem_alloc)); WARN_ON(atomic_read(&sk->sk_wmem_alloc)); if (!sock_flag(sk, SOCK_DEAD)) { pr_err("Attempt to release alive packet socket: %p\n", sk); return; } sk_refcnt_debug_dec(sk); } static int fanout_rr_next(struct packet_fanout *f, unsigned int num) { int x = atomic_read(&f->rr_cur) + 1; if (x >= num) x = 0; return x; } static struct sock *fanout_demux_hash(struct packet_fanout *f, struct sk_buff *skb, unsigned int num) { u32 idx, hash = skb->rxhash; idx = ((u64)hash * num) >> 32; return f->arr[idx]; } static struct sock *fanout_demux_lb(struct packet_fanout *f, struct sk_buff *skb, unsigned int num) { int cur, old; cur = atomic_read(&f->rr_cur); while ((old = atomic_cmpxchg(&f->rr_cur, cur, fanout_rr_next(f, num))) != cur) cur = old; return f->arr[cur]; } static struct sock *fanout_demux_cpu(struct packet_fanout *f, struct sk_buff *skb, unsigned int num) { unsigned int cpu = smp_processor_id(); return f->arr[cpu % num]; } static int packet_rcv_fanout(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev) { struct packet_fanout *f = pt->af_packet_priv; unsigned int num = f->num_members; struct packet_sock *po; struct sock *sk; if (!net_eq(dev_net(dev), read_pnet(&f->net)) || !num) { kfree_skb(skb); return 0; } switch (f->type) { case PACKET_FANOUT_HASH: default: if (f->defrag) { skb = ip_check_defrag(skb, IP_DEFRAG_AF_PACKET); if (!skb) return 0; } skb_get_rxhash(skb); sk = fanout_demux_hash(f, skb, num); break; case PACKET_FANOUT_LB: sk = fanout_demux_lb(f, skb, num); break; case PACKET_FANOUT_CPU: sk = fanout_demux_cpu(f, skb, num); break; } po = pkt_sk(sk); return po->prot_hook.func(skb, dev, &po->prot_hook, orig_dev); } static DEFINE_MUTEX(fanout_mutex); static LIST_HEAD(fanout_list); static void __fanout_link(struct sock *sk, struct packet_sock *po) { struct packet_fanout *f = po->fanout; spin_lock(&f->lock); f->arr[f->num_members] = sk; smp_wmb(); f->num_members++; spin_unlock(&f->lock); } static void __fanout_unlink(struct sock *sk, struct packet_sock *po) { struct packet_fanout *f = po->fanout; int i; spin_lock(&f->lock); for (i = 0; i < f->num_members; i++) { if (f->arr[i] == sk) break; } BUG_ON(i >= f->num_members); f->arr[i] = f->arr[f->num_members - 1]; f->num_members--; spin_unlock(&f->lock); } static int fanout_add(struct sock *sk, u16 id, u16 type_flags) { struct packet_sock *po = pkt_sk(sk); struct packet_fanout *f, *match; u8 type = type_flags & 0xff; u8 defrag = (type_flags & PACKET_FANOUT_FLAG_DEFRAG) ? 1 : 0; int err; switch (type) { case PACKET_FANOUT_HASH: case PACKET_FANOUT_LB: case PACKET_FANOUT_CPU: break; default: return -EINVAL; } if (!po->running) return -EINVAL; if (po->fanout) return -EALREADY; mutex_lock(&fanout_mutex); match = NULL; list_for_each_entry(f, &fanout_list, list) { if (f->id == id && read_pnet(&f->net) == sock_net(sk)) { match = f; break; } } err = -EINVAL; if (match && match->defrag != defrag) goto out; if (!match) { err = -ENOMEM; match = kzalloc(sizeof(*match), GFP_KERNEL); if (!match) goto out; write_pnet(&match->net, sock_net(sk)); match->id = id; match->type = type; match->defrag = defrag; atomic_set(&match->rr_cur, 0); INIT_LIST_HEAD(&match->list); spin_lock_init(&match->lock); atomic_set(&match->sk_ref, 0); match->prot_hook.type = po->prot_hook.type; match->prot_hook.dev = po->prot_hook.dev; match->prot_hook.func = packet_rcv_fanout; match->prot_hook.af_packet_priv = match; dev_add_pack(&match->prot_hook); list_add(&match->list, &fanout_list); } err = -EINVAL; if (match->type == type && match->prot_hook.type == po->prot_hook.type && match->prot_hook.dev == po->prot_hook.dev) { err = -ENOSPC; if (atomic_read(&match->sk_ref) < PACKET_FANOUT_MAX) { __dev_remove_pack(&po->prot_hook); po->fanout = match; atomic_inc(&match->sk_ref); __fanout_link(sk, po); err = 0; } } out: mutex_unlock(&fanout_mutex); return err; } static void fanout_release(struct sock *sk) { struct packet_sock *po = pkt_sk(sk); struct packet_fanout *f; f = po->fanout; if (!f) return; po->fanout = NULL; mutex_lock(&fanout_mutex); if (atomic_dec_and_test(&f->sk_ref)) { list_del(&f->list); dev_remove_pack(&f->prot_hook); kfree(f); } mutex_unlock(&fanout_mutex); } static const struct proto_ops packet_ops; static const struct proto_ops packet_ops_spkt; static int packet_rcv_spkt(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev) { struct sock *sk; struct sockaddr_pkt *spkt; /* * When we registered the protocol we saved the socket in the data * field for just this event. */ sk = pt->af_packet_priv; /* * Yank back the headers [hope the device set this * right or kerboom...] * * Incoming packets have ll header pulled, * push it back. * * For outgoing ones skb->data == skb_mac_header(skb) * so that this procedure is noop. */ if (skb->pkt_type == PACKET_LOOPBACK) goto out; if (!net_eq(dev_net(dev), sock_net(sk))) goto out; skb = skb_share_check(skb, GFP_ATOMIC); if (skb == NULL) goto oom; /* drop any routing info */ skb_dst_drop(skb); /* drop conntrack reference */ nf_reset(skb); spkt = &PACKET_SKB_CB(skb)->sa.pkt; skb_push(skb, skb->data - skb_mac_header(skb)); /* * The SOCK_PACKET socket receives _all_ frames. */ spkt->spkt_family = dev->type; strlcpy(spkt->spkt_device, dev->name, sizeof(spkt->spkt_device)); spkt->spkt_protocol = skb->protocol; /* * Charge the memory to the socket. This is done specifically * to prevent sockets using all the memory up. */ if (sock_queue_rcv_skb(sk, skb) == 0) return 0; out: kfree_skb(skb); oom: return 0; } /* * Output a raw packet to a device layer. This bypasses all the other * protocol layers and you must therefore supply it with a complete frame */ static int packet_sendmsg_spkt(struct kiocb *iocb, struct socket *sock, struct msghdr *msg, size_t len) { struct sock *sk = sock->sk; struct sockaddr_pkt *saddr = (struct sockaddr_pkt *)msg->msg_name; struct sk_buff *skb = NULL; struct net_device *dev; __be16 proto = 0; int err; int extra_len = 0; /* * Get and verify the address. */ if (saddr) { if (msg->msg_namelen < sizeof(struct sockaddr)) return -EINVAL; if (msg->msg_namelen == sizeof(struct sockaddr_pkt)) proto = saddr->spkt_protocol; } else return -ENOTCONN; /* SOCK_PACKET must be sent giving an address */ /* * Find the device first to size check it */ saddr->spkt_device[sizeof(saddr->spkt_device) - 1] = 0; retry: rcu_read_lock(); dev = dev_get_by_name_rcu(sock_net(sk), saddr->spkt_device); err = -ENODEV; if (dev == NULL) goto out_unlock; err = -ENETDOWN; if (!(dev->flags & IFF_UP)) goto out_unlock; /* * You may not queue a frame bigger than the mtu. This is the lowest level * raw protocol and you must do your own fragmentation at this level. */ if (unlikely(sock_flag(sk, SOCK_NOFCS))) { if (!netif_supports_nofcs(dev)) { err = -EPROTONOSUPPORT; goto out_unlock; } extra_len = 4; /* We're doing our own CRC */ } err = -EMSGSIZE; if (len > dev->mtu + dev->hard_header_len + VLAN_HLEN + extra_len) goto out_unlock; if (!skb) { size_t reserved = LL_RESERVED_SPACE(dev); int tlen = dev->needed_tailroom; unsigned int hhlen = dev->header_ops ? dev->hard_header_len : 0; rcu_read_unlock(); skb = sock_wmalloc(sk, len + reserved + tlen, 0, GFP_KERNEL); if (skb == NULL) return -ENOBUFS; /* FIXME: Save some space for broken drivers that write a hard * header at transmission time by themselves. PPP is the notable * one here. This should really be fixed at the driver level. */ skb_reserve(skb, reserved); skb_reset_network_header(skb); /* Try to align data part correctly */ if (hhlen) { skb->data -= hhlen; skb->tail -= hhlen; if (len < hhlen) skb_reset_network_header(skb); } err = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len); if (err) goto out_free; goto retry; } if (len > (dev->mtu + dev->hard_header_len + extra_len)) { /* Earlier code assumed this would be a VLAN pkt, * double-check this now that we have the actual * packet in hand. */ struct ethhdr *ehdr; skb_reset_mac_header(skb); ehdr = eth_hdr(skb); if (ehdr->h_proto != htons(ETH_P_8021Q)) { err = -EMSGSIZE; goto out_unlock; } } skb->protocol = proto; skb->dev = dev; skb->priority = sk->sk_priority; skb->mark = sk->sk_mark; err = sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags); if (err < 0) goto out_unlock; if (unlikely(extra_len == 4)) skb->no_fcs = 1; dev_queue_xmit(skb); rcu_read_unlock(); return len; out_unlock: rcu_read_unlock(); out_free: kfree_skb(skb); return err; } static unsigned int run_filter(const struct sk_buff *skb, const struct sock *sk, unsigned int res) { struct sk_filter *filter; rcu_read_lock(); filter = rcu_dereference(sk->sk_filter); if (filter != NULL) res = SK_RUN_FILTER(filter, skb); rcu_read_unlock(); return res; } /* * This function makes lazy skb cloning in hope that most of packets * are discarded by BPF. * * Note tricky part: we DO mangle shared skb! skb->data, skb->len * and skb->cb are mangled. It works because (and until) packets * falling here are owned by current CPU. Output packets are cloned * by dev_queue_xmit_nit(), input packets are processed by net_bh * sequencially, so that if we return skb to original state on exit, * we will not harm anyone. */ static int packet_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev) { struct sock *sk; struct sockaddr_ll *sll; struct packet_sock *po; u8 *skb_head = skb->data; int skb_len = skb->len; unsigned int snaplen, res; if (skb->pkt_type == PACKET_LOOPBACK) goto drop; sk = pt->af_packet_priv; po = pkt_sk(sk); if (!net_eq(dev_net(dev), sock_net(sk))) goto drop; skb->dev = dev; if (dev->header_ops) { /* The device has an explicit notion of ll header, * exported to higher levels. * * Otherwise, the device hides details of its frame * structure, so that corresponding packet head is * never delivered to user. */ if (sk->sk_type != SOCK_DGRAM) skb_push(skb, skb->data - skb_mac_header(skb)); else if (skb->pkt_type == PACKET_OUTGOING) { /* Special case: outgoing packets have ll header at head */ skb_pull(skb, skb_network_offset(skb)); } } snaplen = skb->len; res = run_filter(skb, sk, snaplen); if (!res) goto drop_n_restore; if (snaplen > res) snaplen = res; if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf) goto drop_n_acct; if (skb_shared(skb)) { struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC); if (nskb == NULL) goto drop_n_acct; if (skb_head != skb->data) { skb->data = skb_head; skb->len = skb_len; } consume_skb(skb); skb = nskb; } BUILD_BUG_ON(sizeof(*PACKET_SKB_CB(skb)) + MAX_ADDR_LEN - 8 > sizeof(skb->cb)); sll = &PACKET_SKB_CB(skb)->sa.ll; sll->sll_family = AF_PACKET; sll->sll_hatype = dev->type; sll->sll_protocol = skb->protocol; sll->sll_pkttype = skb->pkt_type; if (unlikely(po->origdev)) sll->sll_ifindex = orig_dev->ifindex; else sll->sll_ifindex = dev->ifindex; sll->sll_halen = dev_parse_header(skb, sll->sll_addr); PACKET_SKB_CB(skb)->origlen = skb->len; if (pskb_trim(skb, snaplen)) goto drop_n_acct; skb_set_owner_r(skb, sk); skb->dev = NULL; skb_dst_drop(skb); /* drop conntrack reference */ nf_reset(skb); spin_lock(&sk->sk_receive_queue.lock); po->stats.tp_packets++; skb->dropcount = atomic_read(&sk->sk_drops); __skb_queue_tail(&sk->sk_receive_queue, skb); spin_unlock(&sk->sk_receive_queue.lock); sk->sk_data_ready(sk, skb->len); return 0; drop_n_acct: spin_lock(&sk->sk_receive_queue.lock); po->stats.tp_drops++; atomic_inc(&sk->sk_drops); spin_unlock(&sk->sk_receive_queue.lock); drop_n_restore: if (skb_head != skb->data && skb_shared(skb)) { skb->data = skb_head; skb->len = skb_len; } drop: consume_skb(skb); return 0; } static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev) { struct sock *sk; struct packet_sock *po; struct sockaddr_ll *sll; union { struct tpacket_hdr *h1; struct tpacket2_hdr *h2; struct tpacket3_hdr *h3; void *raw; } h; u8 *skb_head = skb->data; int skb_len = skb->len; unsigned int snaplen, res; unsigned long status = TP_STATUS_USER; unsigned short macoff, netoff, hdrlen; struct sk_buff *copy_skb = NULL; struct timeval tv; struct timespec ts; struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb); if (skb->pkt_type == PACKET_LOOPBACK) goto drop; sk = pt->af_packet_priv; po = pkt_sk(sk); if (!net_eq(dev_net(dev), sock_net(sk))) goto drop; if (dev->header_ops) { if (sk->sk_type != SOCK_DGRAM) skb_push(skb, skb->data - skb_mac_header(skb)); else if (skb->pkt_type == PACKET_OUTGOING) { /* Special case: outgoing packets have ll header at head */ skb_pull(skb, skb_network_offset(skb)); } } if (skb->ip_summed == CHECKSUM_PARTIAL) status |= TP_STATUS_CSUMNOTREADY; snaplen = skb->len; res = run_filter(skb, sk, snaplen); if (!res) goto drop_n_restore; if (snaplen > res) snaplen = res; if (sk->sk_type == SOCK_DGRAM) { macoff = netoff = TPACKET_ALIGN(po->tp_hdrlen) + 16 + po->tp_reserve; } else { unsigned int maclen = skb_network_offset(skb); netoff = TPACKET_ALIGN(po->tp_hdrlen + (maclen < 16 ? 16 : maclen)) + po->tp_reserve; macoff = netoff - maclen; } if (po->tp_version <= TPACKET_V2) { if (macoff + snaplen > po->rx_ring.frame_size) { if (po->copy_thresh && atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) { if (skb_shared(skb)) { copy_skb = skb_clone(skb, GFP_ATOMIC); } else { copy_skb = skb_get(skb); skb_head = skb->data; } if (copy_skb) skb_set_owner_r(copy_skb, sk); } snaplen = po->rx_ring.frame_size - macoff; if ((int)snaplen < 0) snaplen = 0; } } spin_lock(&sk->sk_receive_queue.lock); h.raw = packet_current_rx_frame(po, skb, TP_STATUS_KERNEL, (macoff+snaplen)); if (!h.raw) goto ring_is_full; if (po->tp_version <= TPACKET_V2) { packet_increment_rx_head(po, &po->rx_ring); /* * LOSING will be reported till you read the stats, * because it's COR - Clear On Read. * Anyways, moving it for V1/V2 only as V3 doesn't need this * at packet level. */ if (po->stats.tp_drops) status |= TP_STATUS_LOSING; } po->stats.tp_packets++; if (copy_skb) { status |= TP_STATUS_COPY; __skb_queue_tail(&sk->sk_receive_queue, copy_skb); } spin_unlock(&sk->sk_receive_queue.lock); skb_copy_bits(skb, 0, h.raw + macoff, snaplen); switch (po->tp_version) { case TPACKET_V1: h.h1->tp_len = skb->len; h.h1->tp_snaplen = snaplen; h.h1->tp_mac = macoff; h.h1->tp_net = netoff; if ((po->tp_tstamp & SOF_TIMESTAMPING_SYS_HARDWARE) && shhwtstamps->syststamp.tv64) tv = ktime_to_timeval(shhwtstamps->syststamp); else if ((po->tp_tstamp & SOF_TIMESTAMPING_RAW_HARDWARE) && shhwtstamps->hwtstamp.tv64) tv = ktime_to_timeval(shhwtstamps->hwtstamp); else if (skb->tstamp.tv64) tv = ktime_to_timeval(skb->tstamp); else do_gettimeofday(&tv); h.h1->tp_sec = tv.tv_sec; h.h1->tp_usec = tv.tv_usec; hdrlen = sizeof(*h.h1); break; case TPACKET_V2: h.h2->tp_len = skb->len; h.h2->tp_snaplen = snaplen; h.h2->tp_mac = macoff; h.h2->tp_net = netoff; if ((po->tp_tstamp & SOF_TIMESTAMPING_SYS_HARDWARE) && shhwtstamps->syststamp.tv64) ts = ktime_to_timespec(shhwtstamps->syststamp); else if ((po->tp_tstamp & SOF_TIMESTAMPING_RAW_HARDWARE) && shhwtstamps->hwtstamp.tv64) ts = ktime_to_timespec(shhwtstamps->hwtstamp); else if (skb->tstamp.tv64) ts = ktime_to_timespec(skb->tstamp); else getnstimeofday(&ts); h.h2->tp_sec = ts.tv_sec; h.h2->tp_nsec = ts.tv_nsec; if (vlan_tx_tag_present(skb)) { h.h2->tp_vlan_tci = vlan_tx_tag_get(skb); status |= TP_STATUS_VLAN_VALID; } else { h.h2->tp_vlan_tci = 0; } h.h2->tp_padding = 0; hdrlen = sizeof(*h.h2); break; case TPACKET_V3: /* tp_nxt_offset,vlan are already populated above. * So DONT clear those fields here */ h.h3->tp_status |= status; h.h3->tp_len = skb->len; h.h3->tp_snaplen = snaplen; h.h3->tp_mac = macoff; h.h3->tp_net = netoff; if ((po->tp_tstamp & SOF_TIMESTAMPING_SYS_HARDWARE) && shhwtstamps->syststamp.tv64) ts = ktime_to_timespec(shhwtstamps->syststamp); else if ((po->tp_tstamp & SOF_TIMESTAMPING_RAW_HARDWARE) && shhwtstamps->hwtstamp.tv64) ts = ktime_to_timespec(shhwtstamps->hwtstamp); else if (skb->tstamp.tv64) ts = ktime_to_timespec(skb->tstamp); else getnstimeofday(&ts); h.h3->tp_sec = ts.tv_sec; h.h3->tp_nsec = ts.tv_nsec; hdrlen = sizeof(*h.h3); break; default: BUG(); } sll = h.raw + TPACKET_ALIGN(hdrlen); sll->sll_halen = dev_parse_header(skb, sll->sll_addr); sll->sll_family = AF_PACKET; sll->sll_hatype = dev->type; sll->sll_protocol = skb->protocol; sll->sll_pkttype = skb->pkt_type; if (unlikely(po->origdev)) sll->sll_ifindex = orig_dev->ifindex; else sll->sll_ifindex = dev->ifindex; smp_mb(); #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1 { u8 *start, *end; if (po->tp_version <= TPACKET_V2) { end = (u8 *)PAGE_ALIGN((unsigned long)h.raw + macoff + snaplen); for (start = h.raw; start < end; start += PAGE_SIZE) flush_dcache_page(pgv_to_page(start)); } smp_wmb(); } #endif if (po->tp_version <= TPACKET_V2) __packet_set_status(po, h.raw, status); else prb_clear_blk_fill_status(&po->rx_ring); sk->sk_data_ready(sk, 0); drop_n_restore: if (skb_head != skb->data && skb_shared(skb)) { skb->data = skb_head; skb->len = skb_len; } drop: kfree_skb(skb); return 0; ring_is_full: po->stats.tp_drops++; spin_unlock(&sk->sk_receive_queue.lock); sk->sk_data_ready(sk, 0); kfree_skb(copy_skb); goto drop_n_restore; } static void tpacket_destruct_skb(struct sk_buff *skb) { struct packet_sock *po = pkt_sk(skb->sk); void *ph; if (likely(po->tx_ring.pg_vec)) { ph = skb_shinfo(skb)->destructor_arg; BUG_ON(__packet_get_status(po, ph) != TP_STATUS_SENDING); BUG_ON(atomic_read(&po->tx_ring.pending) == 0); atomic_dec(&po->tx_ring.pending); __packet_set_status(po, ph, TP_STATUS_AVAILABLE); } sock_wfree(skb); } static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb, void *frame, struct net_device *dev, int size_max, __be16 proto, unsigned char *addr, int hlen) { union { struct tpacket_hdr *h1; struct tpacket2_hdr *h2; void *raw; } ph; int to_write, offset, len, tp_len, nr_frags, len_max; struct socket *sock = po->sk.sk_socket; struct page *page; void *data; int err; ph.raw = frame; skb->protocol = proto; skb->dev = dev; skb->priority = po->sk.sk_priority; skb->mark = po->sk.sk_mark; skb_shinfo(skb)->destructor_arg = ph.raw; switch (po->tp_version) { case TPACKET_V2: tp_len = ph.h2->tp_len; break; default: tp_len = ph.h1->tp_len; break; } if (unlikely(tp_len > size_max)) { pr_err("packet size is too long (%d > %d)\n", tp_len, size_max); return -EMSGSIZE; } skb_reserve(skb, hlen); skb_reset_network_header(skb); data = ph.raw + po->tp_hdrlen - sizeof(struct sockaddr_ll); to_write = tp_len; if (sock->type == SOCK_DGRAM) { err = dev_hard_header(skb, dev, ntohs(proto), addr, NULL, tp_len); if (unlikely(err < 0)) return -EINVAL; } else if (dev->hard_header_len) { /* net device doesn't like empty head */ if (unlikely(tp_len <= dev->hard_header_len)) { pr_err("packet size is too short (%d < %d)\n", tp_len, dev->hard_header_len); return -EINVAL; } skb_push(skb, dev->hard_header_len); err = skb_store_bits(skb, 0, data, dev->hard_header_len); if (unlikely(err)) return err; data += dev->hard_header_len; to_write -= dev->hard_header_len; } err = -EFAULT; offset = offset_in_page(data); len_max = PAGE_SIZE - offset; len = ((to_write > len_max) ? len_max : to_write); skb->data_len = to_write; skb->len += to_write; skb->truesize += to_write; atomic_add(to_write, &po->sk.sk_wmem_alloc); while (likely(to_write)) { nr_frags = skb_shinfo(skb)->nr_frags; if (unlikely(nr_frags >= MAX_SKB_FRAGS)) { pr_err("Packet exceed the number of skb frags(%lu)\n", MAX_SKB_FRAGS); return -EFAULT; } page = pgv_to_page(data); data += len; flush_dcache_page(page); get_page(page); skb_fill_page_desc(skb, nr_frags, page, offset, len); to_write -= len; offset = 0; len_max = PAGE_SIZE; len = ((to_write > len_max) ? len_max : to_write); } return tp_len; } static int tpacket_snd(struct packet_sock *po, struct msghdr *msg) { struct sk_buff *skb; struct net_device *dev; __be16 proto; bool need_rls_dev = false; int err, reserve = 0; void *ph; struct sockaddr_ll *saddr = (struct sockaddr_ll *)msg->msg_name; int tp_len, size_max; unsigned char *addr; int len_sum = 0; int status = 0; int hlen, tlen; mutex_lock(&po->pg_vec_lock); err = -EBUSY; if (saddr == NULL) { dev = po->prot_hook.dev; proto = po->num; addr = NULL; } else { err = -EINVAL; if (msg->msg_namelen < sizeof(struct sockaddr_ll)) goto out; if (msg->msg_namelen < (saddr->sll_halen + offsetof(struct sockaddr_ll, sll_addr))) goto out; proto = saddr->sll_protocol; addr = saddr->sll_addr; dev = dev_get_by_index(sock_net(&po->sk), saddr->sll_ifindex); need_rls_dev = true; } err = -ENXIO; if (unlikely(dev == NULL)) goto out; reserve = dev->hard_header_len; err = -ENETDOWN; if (unlikely(!(dev->flags & IFF_UP))) goto out_put; size_max = po->tx_ring.frame_size - (po->tp_hdrlen - sizeof(struct sockaddr_ll)); if (size_max > dev->mtu + reserve) size_max = dev->mtu + reserve; do { ph = packet_current_frame(po, &po->tx_ring, TP_STATUS_SEND_REQUEST); if (unlikely(ph == NULL)) { schedule(); continue; } status = TP_STATUS_SEND_REQUEST; hlen = LL_RESERVED_SPACE(dev); tlen = dev->needed_tailroom; skb = sock_alloc_send_skb(&po->sk, hlen + tlen + sizeof(struct sockaddr_ll), 0, &err); if (unlikely(skb == NULL)) goto out_status; tp_len = tpacket_fill_skb(po, skb, ph, dev, size_max, proto, addr, hlen); if (unlikely(tp_len < 0)) { if (po->tp_loss) { __packet_set_status(po, ph, TP_STATUS_AVAILABLE); packet_increment_head(&po->tx_ring); kfree_skb(skb); continue; } else { status = TP_STATUS_WRONG_FORMAT; err = tp_len; goto out_status; } } skb->destructor = tpacket_destruct_skb; __packet_set_status(po, ph, TP_STATUS_SENDING); atomic_inc(&po->tx_ring.pending); status = TP_STATUS_SEND_REQUEST; err = dev_queue_xmit(skb); if (unlikely(err > 0)) { err = net_xmit_errno(err); if (err && __packet_get_status(po, ph) == TP_STATUS_AVAILABLE) { /* skb was destructed already */ skb = NULL; goto out_status; } /* * skb was dropped but not destructed yet; * let's treat it like congestion or err < 0 */ err = 0; } packet_increment_head(&po->tx_ring); len_sum += tp_len; } while (likely((ph != NULL) || ((!(msg->msg_flags & MSG_DONTWAIT)) && (atomic_read(&po->tx_ring.pending)))) ); err = len_sum; goto out_put; out_status: __packet_set_status(po, ph, status); kfree_skb(skb); out_put: if (need_rls_dev) dev_put(dev); out: mutex_unlock(&po->pg_vec_lock); return err; } static struct sk_buff *packet_alloc_skb(struct sock *sk, size_t prepad, size_t reserve, size_t len, size_t linear, int noblock, int *err) { struct sk_buff *skb; /* Under a page? Don't bother with paged skb. */ if (prepad + len < PAGE_SIZE || !linear) linear = len; skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock, err); if (!skb) return NULL; skb_reserve(skb, reserve); skb_put(skb, linear); skb->data_len = len - linear; skb->len += len - linear; return skb; } static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len) { struct sock *sk = sock->sk; struct sockaddr_ll *saddr = (struct sockaddr_ll *)msg->msg_name; struct sk_buff *skb; struct net_device *dev; __be16 proto; bool need_rls_dev = false; unsigned char *addr; int err, reserve = 0; struct virtio_net_hdr vnet_hdr = { 0 }; int offset = 0; int vnet_hdr_len; struct packet_sock *po = pkt_sk(sk); unsigned short gso_type = 0; int hlen, tlen; int extra_len = 0; /* * Get and verify the address. */ if (saddr == NULL) { dev = po->prot_hook.dev; proto = po->num; addr = NULL; } else { err = -EINVAL; if (msg->msg_namelen < sizeof(struct sockaddr_ll)) goto out; if (msg->msg_namelen < (saddr->sll_halen + offsetof(struct sockaddr_ll, sll_addr))) goto out; proto = saddr->sll_protocol; addr = saddr->sll_addr; dev = dev_get_by_index(sock_net(sk), saddr->sll_ifindex); need_rls_dev = true; } err = -ENXIO; if (dev == NULL) goto out_unlock; if (sock->type == SOCK_RAW) reserve = dev->hard_header_len; err = -ENETDOWN; if (!(dev->flags & IFF_UP)) goto out_unlock; if (po->has_vnet_hdr) { vnet_hdr_len = sizeof(vnet_hdr); err = -EINVAL; if (len < vnet_hdr_len) goto out_unlock; len -= vnet_hdr_len; err = memcpy_fromiovec((void *)&vnet_hdr, msg->msg_iov, vnet_hdr_len); if (err < 0) goto out_unlock; if ((vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) && (vnet_hdr.csum_start + vnet_hdr.csum_offset + 2 > vnet_hdr.hdr_len)) vnet_hdr.hdr_len = vnet_hdr.csum_start + vnet_hdr.csum_offset + 2; err = -EINVAL; if (vnet_hdr.hdr_len > len) goto out_unlock; if (vnet_hdr.gso_type != VIRTIO_NET_HDR_GSO_NONE) { switch (vnet_hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) { case VIRTIO_NET_HDR_GSO_TCPV4: gso_type = SKB_GSO_TCPV4; break; case VIRTIO_NET_HDR_GSO_TCPV6: gso_type = SKB_GSO_TCPV6; break; case VIRTIO_NET_HDR_GSO_UDP: gso_type = SKB_GSO_UDP; break; default: goto out_unlock; } if (vnet_hdr.gso_type & VIRTIO_NET_HDR_GSO_ECN) gso_type |= SKB_GSO_TCP_ECN; if (vnet_hdr.gso_size == 0) goto out_unlock; } } if (unlikely(sock_flag(sk, SOCK_NOFCS))) { if (!netif_supports_nofcs(dev)) { err = -EPROTONOSUPPORT; goto out_unlock; } extra_len = 4; /* We're doing our own CRC */ } err = -EMSGSIZE; if (!gso_type && (len > dev->mtu + reserve + VLAN_HLEN + extra_len)) goto out_unlock; err = -ENOBUFS; hlen = LL_RESERVED_SPACE(dev); tlen = dev->needed_tailroom; skb = packet_alloc_skb(sk, hlen + tlen, hlen, len, vnet_hdr.hdr_len, msg->msg_flags & MSG_DONTWAIT, &err); if (skb == NULL) goto out_unlock; skb_set_network_header(skb, reserve); err = -EINVAL; if (sock->type == SOCK_DGRAM && (offset = dev_hard_header(skb, dev, ntohs(proto), addr, NULL, len)) < 0) goto out_free; /* Returns -EFAULT on error */ err = skb_copy_datagram_from_iovec(skb, offset, msg->msg_iov, 0, len); if (err) goto out_free; err = sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags); if (err < 0) goto out_free; if (!gso_type && (len > dev->mtu + reserve + extra_len)) { /* Earlier code assumed this would be a VLAN pkt, * double-check this now that we have the actual * packet in hand. */ struct ethhdr *ehdr; skb_reset_mac_header(skb); ehdr = eth_hdr(skb); if (ehdr->h_proto != htons(ETH_P_8021Q)) { err = -EMSGSIZE; goto out_free; } } skb->protocol = proto; skb->dev = dev; skb->priority = sk->sk_priority; skb->mark = sk->sk_mark; if (po->has_vnet_hdr) { if (vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) { if (!skb_partial_csum_set(skb, vnet_hdr.csum_start, vnet_hdr.csum_offset)) { err = -EINVAL; goto out_free; } } skb_shinfo(skb)->gso_size = vnet_hdr.gso_size; skb_shinfo(skb)->gso_type = gso_type; /* Header must be checked, and gso_segs computed. */ skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY; skb_shinfo(skb)->gso_segs = 0; len += vnet_hdr_len; } if (unlikely(extra_len == 4)) skb->no_fcs = 1; /* * Now send it */ err = dev_queue_xmit(skb); if (err > 0 && (err = net_xmit_errno(err)) != 0) goto out_unlock; if (need_rls_dev) dev_put(dev); return len; out_free: kfree_skb(skb); out_unlock: if (dev && need_rls_dev) dev_put(dev); out: return err; } static int packet_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg, size_t len) { struct sock *sk = sock->sk; struct packet_sock *po = pkt_sk(sk); if (po->tx_ring.pg_vec) return tpacket_snd(po, msg); else return packet_snd(sock, msg, len); } /* * Close a PACKET socket. This is fairly simple. We immediately go * to 'closed' state and remove our protocol entry in the device list. */ static int packet_release(struct socket *sock) { struct sock *sk = sock->sk; struct packet_sock *po; struct net *net; union tpacket_req_u req_u; if (!sk) return 0; net = sock_net(sk); po = pkt_sk(sk); spin_lock_bh(&net->packet.sklist_lock); sk_del_node_init_rcu(sk); sock_prot_inuse_add(net, sk->sk_prot, -1); spin_unlock_bh(&net->packet.sklist_lock); spin_lock(&po->bind_lock); unregister_prot_hook(sk, false); if (po->prot_hook.dev) { dev_put(po->prot_hook.dev); po->prot_hook.dev = NULL; } spin_unlock(&po->bind_lock); packet_flush_mclist(sk); memset(&req_u, 0, sizeof(req_u)); if (po->rx_ring.pg_vec) packet_set_ring(sk, &req_u, 1, 0); if (po->tx_ring.pg_vec) packet_set_ring(sk, &req_u, 1, 1); fanout_release(sk); synchronize_net(); /* * Now the socket is dead. No more input will appear. */ sock_orphan(sk); sock->sk = NULL; /* Purge queues */ skb_queue_purge(&sk->sk_receive_queue); sk_refcnt_debug_release(sk); sock_put(sk); return 0; } /* * Attach a packet hook. */ static int packet_do_bind(struct sock *sk, struct net_device *dev, __be16 protocol) { struct packet_sock *po = pkt_sk(sk); if (po->fanout) { if (dev) dev_put(dev); return -EINVAL; } lock_sock(sk); spin_lock(&po->bind_lock); unregister_prot_hook(sk, true); po->num = protocol; po->prot_hook.type = protocol; if (po->prot_hook.dev) dev_put(po->prot_hook.dev); po->prot_hook.dev = dev; po->ifindex = dev ? dev->ifindex : 0; if (protocol == 0) goto out_unlock; if (!dev || (dev->flags & IFF_UP)) { register_prot_hook(sk); } else { sk->sk_err = ENETDOWN; if (!sock_flag(sk, SOCK_DEAD)) sk->sk_error_report(sk); } out_unlock: spin_unlock(&po->bind_lock); release_sock(sk); return 0; } /* * Bind a packet socket to a device */ static int packet_bind_spkt(struct socket *sock, struct sockaddr *uaddr, int addr_len) { struct sock *sk = sock->sk; char name[15]; struct net_device *dev; int err = -ENODEV; /* * Check legality */ if (addr_len != sizeof(struct sockaddr)) return -EINVAL; strlcpy(name, uaddr->sa_data, sizeof(name)); dev = dev_get_by_name(sock_net(sk), name); if (dev) err = packet_do_bind(sk, dev, pkt_sk(sk)->num); return err; } static int packet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) { struct sockaddr_ll *sll = (struct sockaddr_ll *)uaddr; struct sock *sk = sock->sk; struct net_device *dev = NULL; int err; /* * Check legality */ if (addr_len < sizeof(struct sockaddr_ll)) return -EINVAL; if (sll->sll_family != AF_PACKET) return -EINVAL; if (sll->sll_ifindex) { err = -ENODEV; dev = dev_get_by_index(sock_net(sk), sll->sll_ifindex); if (dev == NULL) goto out; } err = packet_do_bind(sk, dev, sll->sll_protocol ? : pkt_sk(sk)->num); out: return err; } static struct proto packet_proto = { .name = "PACKET", .owner = THIS_MODULE, .obj_size = sizeof(struct packet_sock), }; /* * Create a packet of type SOCK_PACKET. */ static int packet_create(struct net *net, struct socket *sock, int protocol, int kern) { struct sock *sk; struct packet_sock *po; __be16 proto = (__force __be16)protocol; /* weird, but documented */ int err; if (!capable(CAP_NET_RAW)) return -EPERM; if (sock->type != SOCK_DGRAM && sock->type != SOCK_RAW && sock->type != SOCK_PACKET) return -ESOCKTNOSUPPORT; sock->state = SS_UNCONNECTED; err = -ENOBUFS; sk = sk_alloc(net, PF_PACKET, GFP_KERNEL, &packet_proto); if (sk == NULL) goto out; sock->ops = &packet_ops; if (sock->type == SOCK_PACKET) sock->ops = &packet_ops_spkt; sock_init_data(sock, sk); po = pkt_sk(sk); sk->sk_family = PF_PACKET; po->num = proto; sk->sk_destruct = packet_sock_destruct; sk_refcnt_debug_inc(sk); /* * Attach a protocol block */ spin_lock_init(&po->bind_lock); mutex_init(&po->pg_vec_lock); po->prot_hook.func = packet_rcv; if (sock->type == SOCK_PACKET) po->prot_hook.func = packet_rcv_spkt; po->prot_hook.af_packet_priv = sk; if (proto) { po->prot_hook.type = proto; register_prot_hook(sk); } spin_lock_bh(&net->packet.sklist_lock); sk_add_node_rcu(sk, &net->packet.sklist); sock_prot_inuse_add(net, &packet_proto, 1); spin_unlock_bh(&net->packet.sklist_lock); return 0; out: return err; } static int packet_recv_error(struct sock *sk, struct msghdr *msg, int len) { struct sock_exterr_skb *serr; struct sk_buff *skb, *skb2; int copied, err; err = -EAGAIN; skb = skb_dequeue(&sk->sk_error_queue); if (skb == NULL) goto out; copied = skb->len; if (copied > len) { msg->msg_flags |= MSG_TRUNC; copied = len; } err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied); if (err) goto out_free_skb; sock_recv_timestamp(msg, sk, skb); serr = SKB_EXT_ERR(skb); put_cmsg(msg, SOL_PACKET, PACKET_TX_TIMESTAMP, sizeof(serr->ee), &serr->ee); msg->msg_flags |= MSG_ERRQUEUE; err = copied; /* Reset and regenerate socket error */ spin_lock_bh(&sk->sk_error_queue.lock); sk->sk_err = 0; if ((skb2 = skb_peek(&sk->sk_error_queue)) != NULL) { sk->sk_err = SKB_EXT_ERR(skb2)->ee.ee_errno; spin_unlock_bh(&sk->sk_error_queue.lock); sk->sk_error_report(sk); } else spin_unlock_bh(&sk->sk_error_queue.lock); out_free_skb: kfree_skb(skb); out: return err; } /* * Pull a packet from our receive queue and hand it to the user. * If necessary we block. */ static int packet_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg, size_t len, int flags) { struct sock *sk = sock->sk; struct sk_buff *skb; int copied, err; struct sockaddr_ll *sll; int vnet_hdr_len = 0; err = -EINVAL; if (flags & ~(MSG_PEEK|MSG_DONTWAIT|MSG_TRUNC|MSG_CMSG_COMPAT|MSG_ERRQUEUE)) goto out; #if 0 /* What error should we return now? EUNATTACH? */ if (pkt_sk(sk)->ifindex < 0) return -ENODEV; #endif if (flags & MSG_ERRQUEUE) { err = packet_recv_error(sk, msg, len); goto out; } /* * Call the generic datagram receiver. This handles all sorts * of horrible races and re-entrancy so we can forget about it * in the protocol layers. * * Now it will return ENETDOWN, if device have just gone down, * but then it will block. */ skb = skb_recv_datagram(sk, flags, flags & MSG_DONTWAIT, &err); /* * An error occurred so return it. Because skb_recv_datagram() * handles the blocking we don't see and worry about blocking * retries. */ if (skb == NULL) goto out; if (pkt_sk(sk)->has_vnet_hdr) { struct virtio_net_hdr vnet_hdr = { 0 }; err = -EINVAL; vnet_hdr_len = sizeof(vnet_hdr); if (len < vnet_hdr_len) goto out_free; len -= vnet_hdr_len; if (skb_is_gso(skb)) { struct skb_shared_info *sinfo = skb_shinfo(skb); /* This is a hint as to how much should be linear. */ vnet_hdr.hdr_len = skb_headlen(skb); vnet_hdr.gso_size = sinfo->gso_size; if (sinfo->gso_type & SKB_GSO_TCPV4) vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4; else if (sinfo->gso_type & SKB_GSO_TCPV6) vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV6; else if (sinfo->gso_type & SKB_GSO_UDP) vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_UDP; else if (sinfo->gso_type & SKB_GSO_FCOE) goto out_free; else BUG(); if (sinfo->gso_type & SKB_GSO_TCP_ECN) vnet_hdr.gso_type |= VIRTIO_NET_HDR_GSO_ECN; } else vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE; if (skb->ip_summed == CHECKSUM_PARTIAL) { vnet_hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM; vnet_hdr.csum_start = skb_checksum_start_offset(skb); vnet_hdr.csum_offset = skb->csum_offset; } else if (skb->ip_summed == CHECKSUM_UNNECESSARY) { vnet_hdr.flags = VIRTIO_NET_HDR_F_DATA_VALID; } /* else everything is zero */ err = memcpy_toiovec(msg->msg_iov, (void *)&vnet_hdr, vnet_hdr_len); if (err < 0) goto out_free; } /* * If the address length field is there to be filled in, we fill * it in now. */ sll = &PACKET_SKB_CB(skb)->sa.ll; if (sock->type == SOCK_PACKET) msg->msg_namelen = sizeof(struct sockaddr_pkt); else msg->msg_namelen = sll->sll_halen + offsetof(struct sockaddr_ll, sll_addr); /* * You lose any data beyond the buffer you gave. If it worries a * user program they can ask the device for its MTU anyway. */ copied = skb->len; if (copied > len) { copied = len; msg->msg_flags |= MSG_TRUNC; } err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied); if (err) goto out_free; sock_recv_ts_and_drops(msg, sk, skb); if (msg->msg_name) memcpy(msg->msg_name, &PACKET_SKB_CB(skb)->sa, msg->msg_namelen); if (pkt_sk(sk)->auxdata) { struct tpacket_auxdata aux; aux.tp_status = TP_STATUS_USER; if (skb->ip_summed == CHECKSUM_PARTIAL) aux.tp_status |= TP_STATUS_CSUMNOTREADY; aux.tp_len = PACKET_SKB_CB(skb)->origlen; aux.tp_snaplen = skb->len; aux.tp_mac = 0; aux.tp_net = skb_network_offset(skb); if (vlan_tx_tag_present(skb)) { aux.tp_vlan_tci = vlan_tx_tag_get(skb); aux.tp_status |= TP_STATUS_VLAN_VALID; } else { aux.tp_vlan_tci = 0; } aux.tp_padding = 0; put_cmsg(msg, SOL_PACKET, PACKET_AUXDATA, sizeof(aux), &aux); } /* * Free or return the buffer as appropriate. Again this * hides all the races and re-entrancy issues from us. */ err = vnet_hdr_len + ((flags&MSG_TRUNC) ? skb->len : copied); out_free: skb_free_datagram(sk, skb); out: return err; } static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr, int *uaddr_len, int peer) { struct net_device *dev; struct sock *sk = sock->sk; if (peer) return -EOPNOTSUPP; uaddr->sa_family = AF_PACKET; rcu_read_lock(); dev = dev_get_by_index_rcu(sock_net(sk), pkt_sk(sk)->ifindex); if (dev) strncpy(uaddr->sa_data, dev->name, 14); else memset(uaddr->sa_data, 0, 14); rcu_read_unlock(); *uaddr_len = sizeof(*uaddr); return 0; } static int packet_getname(struct socket *sock, struct sockaddr *uaddr, int *uaddr_len, int peer) { struct net_device *dev; struct sock *sk = sock->sk; struct packet_sock *po = pkt_sk(sk); DECLARE_SOCKADDR(struct sockaddr_ll *, sll, uaddr); if (peer) return -EOPNOTSUPP; sll->sll_family = AF_PACKET; sll->sll_ifindex = po->ifindex; sll->sll_protocol = po->num; sll->sll_pkttype = 0; rcu_read_lock(); dev = dev_get_by_index_rcu(sock_net(sk), po->ifindex); if (dev) { sll->sll_hatype = dev->type; sll->sll_halen = dev->addr_len; memcpy(sll->sll_addr, dev->dev_addr, dev->addr_len); } else { sll->sll_hatype = 0; /* Bad: we have no ARPHRD_UNSPEC */ sll->sll_halen = 0; } rcu_read_unlock(); *uaddr_len = offsetof(struct sockaddr_ll, sll_addr) + sll->sll_halen; return 0; } static int packet_dev_mc(struct net_device *dev, struct packet_mclist *i, int what) { switch (i->type) { case PACKET_MR_MULTICAST: if (i->alen != dev->addr_len) return -EINVAL; if (what > 0) return dev_mc_add(dev, i->addr); else return dev_mc_del(dev, i->addr); break; case PACKET_MR_PROMISC: return dev_set_promiscuity(dev, what); break; case PACKET_MR_ALLMULTI: return dev_set_allmulti(dev, what); break; case PACKET_MR_UNICAST: if (i->alen != dev->addr_len) return -EINVAL; if (what > 0) return dev_uc_add(dev, i->addr); else return dev_uc_del(dev, i->addr); break; default: break; } return 0; } static void packet_dev_mclist(struct net_device *dev, struct packet_mclist *i, int what) { for ( ; i; i = i->next) { if (i->ifindex == dev->ifindex) packet_dev_mc(dev, i, what); } } static int packet_mc_add(struct sock *sk, struct packet_mreq_max *mreq) { struct packet_sock *po = pkt_sk(sk); struct packet_mclist *ml, *i; struct net_device *dev; int err; rtnl_lock(); err = -ENODEV; dev = __dev_get_by_index(sock_net(sk), mreq->mr_ifindex); if (!dev) goto done; err = -EINVAL; if (mreq->mr_alen > dev->addr_len) goto done; err = -ENOBUFS; i = kmalloc(sizeof(*i), GFP_KERNEL); if (i == NULL) goto done; err = 0; for (ml = po->mclist; ml; ml = ml->next) { if (ml->ifindex == mreq->mr_ifindex && ml->type == mreq->mr_type && ml->alen == mreq->mr_alen && memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) { ml->count++; /* Free the new element ... */ kfree(i); goto done; } } i->type = mreq->mr_type; i->ifindex = mreq->mr_ifindex; i->alen = mreq->mr_alen; memcpy(i->addr, mreq->mr_address, i->alen); i->count = 1; i->next = po->mclist; po->mclist = i; err = packet_dev_mc(dev, i, 1); if (err) { po->mclist = i->next; kfree(i); } done: rtnl_unlock(); return err; } static int packet_mc_drop(struct sock *sk, struct packet_mreq_max *mreq) { struct packet_mclist *ml, **mlp; rtnl_lock(); for (mlp = &pkt_sk(sk)->mclist; (ml = *mlp) != NULL; mlp = &ml->next) { if (ml->ifindex == mreq->mr_ifindex && ml->type == mreq->mr_type && ml->alen == mreq->mr_alen && memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) { if (--ml->count == 0) { struct net_device *dev; *mlp = ml->next; dev = __dev_get_by_index(sock_net(sk), ml->ifindex); if (dev) packet_dev_mc(dev, ml, -1); kfree(ml); } rtnl_unlock(); return 0; } } rtnl_unlock(); return -EADDRNOTAVAIL; } static void packet_flush_mclist(struct sock *sk) { struct packet_sock *po = pkt_sk(sk); struct packet_mclist *ml; if (!po->mclist) return; rtnl_lock(); while ((ml = po->mclist) != NULL) { struct net_device *dev; po->mclist = ml->next; dev = __dev_get_by_index(sock_net(sk), ml->ifindex); if (dev != NULL) packet_dev_mc(dev, ml, -1); kfree(ml); } rtnl_unlock(); } static int packet_setsockopt(struct socket *sock, int level, int optname, char __user *optval, unsigned int optlen) { struct sock *sk = sock->sk; struct packet_sock *po = pkt_sk(sk); int ret; if (level != SOL_PACKET) return -ENOPROTOOPT; switch (optname) { case PACKET_ADD_MEMBERSHIP: case PACKET_DROP_MEMBERSHIP: { struct packet_mreq_max mreq; int len = optlen; memset(&mreq, 0, sizeof(mreq)); if (len < sizeof(struct packet_mreq)) return -EINVAL; if (len > sizeof(mreq)) len = sizeof(mreq); if (copy_from_user(&mreq, optval, len)) return -EFAULT; if (len < (mreq.mr_alen + offsetof(struct packet_mreq, mr_address))) return -EINVAL; if (optname == PACKET_ADD_MEMBERSHIP) ret = packet_mc_add(sk, &mreq); else ret = packet_mc_drop(sk, &mreq); return ret; } case PACKET_RX_RING: case PACKET_TX_RING: { union tpacket_req_u req_u; int len; switch (po->tp_version) { case TPACKET_V1: case TPACKET_V2: len = sizeof(req_u.req); break; case TPACKET_V3: default: len = sizeof(req_u.req3); break; } if (optlen < len) return -EINVAL; if (pkt_sk(sk)->has_vnet_hdr) return -EINVAL; if (copy_from_user(&req_u.req, optval, len)) return -EFAULT; return packet_set_ring(sk, &req_u, 0, optname == PACKET_TX_RING); } case PACKET_COPY_THRESH: { int val; if (optlen != sizeof(val)) return -EINVAL; if (copy_from_user(&val, optval, sizeof(val))) return -EFAULT; pkt_sk(sk)->copy_thresh = val; return 0; } case PACKET_VERSION: { int val; if (optlen != sizeof(val)) return -EINVAL; if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) return -EBUSY; if (copy_from_user(&val, optval, sizeof(val))) return -EFAULT; switch (val) { case TPACKET_V1: case TPACKET_V2: case TPACKET_V3: po->tp_version = val; return 0; default: return -EINVAL; } } case PACKET_RESERVE: { unsigned int val; if (optlen != sizeof(val)) return -EINVAL; if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) return -EBUSY; if (copy_from_user(&val, optval, sizeof(val))) return -EFAULT; po->tp_reserve = val; return 0; } case PACKET_LOSS: { unsigned int val; if (optlen != sizeof(val)) return -EINVAL; if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) return -EBUSY; if (copy_from_user(&val, optval, sizeof(val))) return -EFAULT; po->tp_loss = !!val; return 0; } case PACKET_AUXDATA: { int val; if (optlen < sizeof(val)) return -EINVAL; if (copy_from_user(&val, optval, sizeof(val))) return -EFAULT; po->auxdata = !!val; return 0; } case PACKET_ORIGDEV: { int val; if (optlen < sizeof(val)) return -EINVAL; if (copy_from_user(&val, optval, sizeof(val))) return -EFAULT; po->origdev = !!val; return 0; } case PACKET_VNET_HDR: { int val; if (sock->type != SOCK_RAW) return -EINVAL; if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) return -EBUSY; if (optlen < sizeof(val)) return -EINVAL; if (copy_from_user(&val, optval, sizeof(val))) return -EFAULT; po->has_vnet_hdr = !!val; return 0; } case PACKET_TIMESTAMP: { int val; if (optlen != sizeof(val)) return -EINVAL; if (copy_from_user(&val, optval, sizeof(val))) return -EFAULT; po->tp_tstamp = val; return 0; } case PACKET_FANOUT: { int val; if (optlen != sizeof(val)) return -EINVAL; if (copy_from_user(&val, optval, sizeof(val))) return -EFAULT; return fanout_add(sk, val & 0xffff, val >> 16); } default: return -ENOPROTOOPT; } } static int packet_getsockopt(struct socket *sock, int level, int optname, char __user *optval, int __user *optlen) { int len; int val, lv = sizeof(val); struct sock *sk = sock->sk; struct packet_sock *po = pkt_sk(sk); void *data = &val; struct tpacket_stats st; union tpacket_stats_u st_u; if (level != SOL_PACKET) return -ENOPROTOOPT; if (get_user(len, optlen)) return -EFAULT; if (len < 0) return -EINVAL; switch (optname) { case PACKET_STATISTICS: spin_lock_bh(&sk->sk_receive_queue.lock); if (po->tp_version == TPACKET_V3) { lv = sizeof(struct tpacket_stats_v3); memcpy(&st_u.stats3, &po->stats, sizeof(struct tpacket_stats)); st_u.stats3.tp_freeze_q_cnt = po->stats_u.stats3.tp_freeze_q_cnt; st_u.stats3.tp_packets += po->stats.tp_drops; data = &st_u.stats3; } else { lv = sizeof(struct tpacket_stats); st = po->stats; st.tp_packets += st.tp_drops; data = &st; } memset(&po->stats, 0, sizeof(st)); spin_unlock_bh(&sk->sk_receive_queue.lock); break; case PACKET_AUXDATA: val = po->auxdata; break; case PACKET_ORIGDEV: val = po->origdev; break; case PACKET_VNET_HDR: val = po->has_vnet_hdr; break; case PACKET_VERSION: val = po->tp_version; break; case PACKET_HDRLEN: if (len > sizeof(int)) len = sizeof(int); if (copy_from_user(&val, optval, len)) return -EFAULT; switch (val) { case TPACKET_V1: val = sizeof(struct tpacket_hdr); break; case TPACKET_V2: val = sizeof(struct tpacket2_hdr); break; case TPACKET_V3: val = sizeof(struct tpacket3_hdr); break; default: return -EINVAL; } break; case PACKET_RESERVE: val = po->tp_reserve; break; case PACKET_LOSS: val = po->tp_loss; break; case PACKET_TIMESTAMP: val = po->tp_tstamp; break; case PACKET_FANOUT: val = (po->fanout ? ((u32)po->fanout->id | ((u32)po->fanout->type << 16)) : 0); break; default: return -ENOPROTOOPT; } if (len > lv) len = lv; if (put_user(len, optlen)) return -EFAULT; if (copy_to_user(optval, data, len)) return -EFAULT; return 0; } static int packet_notifier(struct notifier_block *this, unsigned long msg, void *data) { struct sock *sk; struct hlist_node *node; struct net_device *dev = data; struct net *net = dev_net(dev); rcu_read_lock(); sk_for_each_rcu(sk, node, &net->packet.sklist) { struct packet_sock *po = pkt_sk(sk); switch (msg) { case NETDEV_UNREGISTER: if (po->mclist) packet_dev_mclist(dev, po->mclist, -1); /* fallthrough */ case NETDEV_DOWN: if (dev->ifindex == po->ifindex) { spin_lock(&po->bind_lock); if (po->running) { __unregister_prot_hook(sk, false); sk->sk_err = ENETDOWN; if (!sock_flag(sk, SOCK_DEAD)) sk->sk_error_report(sk); } if (msg == NETDEV_UNREGISTER) { po->ifindex = -1; if (po->prot_hook.dev) dev_put(po->prot_hook.dev); po->prot_hook.dev = NULL; } spin_unlock(&po->bind_lock); } break; case NETDEV_UP: if (dev->ifindex == po->ifindex) { spin_lock(&po->bind_lock); if (po->num) register_prot_hook(sk); spin_unlock(&po->bind_lock); } break; } } rcu_read_unlock(); return NOTIFY_DONE; } static int packet_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg) { struct sock *sk = sock->sk; switch (cmd) { case SIOCOUTQ: { int amount = sk_wmem_alloc_get(sk); return put_user(amount, (int __user *)arg); } case SIOCINQ: { struct sk_buff *skb; int amount = 0; spin_lock_bh(&sk->sk_receive_queue.lock); skb = skb_peek(&sk->sk_receive_queue); if (skb) amount = skb->len; spin_unlock_bh(&sk->sk_receive_queue.lock); return put_user(amount, (int __user *)arg); } case SIOCGSTAMP: return sock_get_timestamp(sk, (struct timeval __user *)arg); case SIOCGSTAMPNS: return sock_get_timestampns(sk, (struct timespec __user *)arg); #ifdef CONFIG_INET case SIOCADDRT: case SIOCDELRT: case SIOCDARP: case SIOCGARP: case SIOCSARP: case SIOCGIFADDR: case SIOCSIFADDR: case SIOCGIFBRDADDR: case SIOCSIFBRDADDR: case SIOCGIFNETMASK: case SIOCSIFNETMASK: case SIOCGIFDSTADDR: case SIOCSIFDSTADDR: case SIOCSIFFLAGS: return inet_dgram_ops.ioctl(sock, cmd, arg); #endif default: return -ENOIOCTLCMD; } return 0; } static unsigned int packet_poll(struct file *file, struct socket *sock, poll_table *wait) { struct sock *sk = sock->sk; struct packet_sock *po = pkt_sk(sk); unsigned int mask = datagram_poll(file, sock, wait); spin_lock_bh(&sk->sk_receive_queue.lock); if (po->rx_ring.pg_vec) { if (!packet_previous_rx_frame(po, &po->rx_ring, TP_STATUS_KERNEL)) mask |= POLLIN | POLLRDNORM; } spin_unlock_bh(&sk->sk_receive_queue.lock); spin_lock_bh(&sk->sk_write_queue.lock); if (po->tx_ring.pg_vec) { if (packet_current_frame(po, &po->tx_ring, TP_STATUS_AVAILABLE)) mask |= POLLOUT | POLLWRNORM; } spin_unlock_bh(&sk->sk_write_queue.lock); return mask; } /* Dirty? Well, I still did not learn better way to account * for user mmaps. */ static void packet_mm_open(struct vm_area_struct *vma) { struct file *file = vma->vm_file; struct socket *sock = file->private_data; struct sock *sk = sock->sk; if (sk) atomic_inc(&pkt_sk(sk)->mapped); } static void packet_mm_close(struct vm_area_struct *vma) { struct file *file = vma->vm_file; struct socket *sock = file->private_data; struct sock *sk = sock->sk; if (sk) atomic_dec(&pkt_sk(sk)->mapped); } static const struct vm_operations_struct packet_mmap_ops = { .open = packet_mm_open, .close = packet_mm_close, }; static void free_pg_vec(struct pgv *pg_vec, unsigned int order, unsigned int len) { int i; for (i = 0; i < len; i++) { if (likely(pg_vec[i].buffer)) { if (is_vmalloc_addr(pg_vec[i].buffer)) vfree(pg_vec[i].buffer); else free_pages((unsigned long)pg_vec[i].buffer, order); pg_vec[i].buffer = NULL; } } kfree(pg_vec); } static char *alloc_one_pg_vec_page(unsigned long order) { char *buffer = NULL; gfp_t gfp_flags = GFP_KERNEL | __GFP_COMP | __GFP_ZERO | __GFP_NOWARN | __GFP_NORETRY; buffer = (char *) __get_free_pages(gfp_flags, order); if (buffer) return buffer; /* * __get_free_pages failed, fall back to vmalloc */ buffer = vzalloc((1 << order) * PAGE_SIZE); if (buffer) return buffer; /* * vmalloc failed, lets dig into swap here */ gfp_flags &= ~__GFP_NORETRY; buffer = (char *)__get_free_pages(gfp_flags, order); if (buffer) return buffer; /* * complete and utter failure */ return NULL; } static struct pgv *alloc_pg_vec(struct tpacket_req *req, int order) { unsigned int block_nr = req->tp_block_nr; struct pgv *pg_vec; int i; pg_vec = kcalloc(block_nr, sizeof(struct pgv), GFP_KERNEL); if (unlikely(!pg_vec)) goto out; for (i = 0; i < block_nr; i++) { pg_vec[i].buffer = alloc_one_pg_vec_page(order); if (unlikely(!pg_vec[i].buffer)) goto out_free_pgvec; } out: return pg_vec; out_free_pgvec: free_pg_vec(pg_vec, order, block_nr); pg_vec = NULL; goto out; } static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u, int closing, int tx_ring) { struct pgv *pg_vec = NULL; struct packet_sock *po = pkt_sk(sk); int was_running, order = 0; struct packet_ring_buffer *rb; struct sk_buff_head *rb_queue; __be16 num; int err = -EINVAL; /* Added to avoid minimal code churn */ struct tpacket_req *req = &req_u->req; /* Opening a Tx-ring is NOT supported in TPACKET_V3 */ if (!closing && tx_ring && (po->tp_version > TPACKET_V2)) { WARN(1, "Tx-ring is not supported.\n"); goto out; } rb = tx_ring ? &po->tx_ring : &po->rx_ring; rb_queue = tx_ring ? &sk->sk_write_queue : &sk->sk_receive_queue; err = -EBUSY; if (!closing) { if (atomic_read(&po->mapped)) goto out; if (atomic_read(&rb->pending)) goto out; } if (req->tp_block_nr) { /* Sanity tests and some calculations */ err = -EBUSY; if (unlikely(rb->pg_vec)) goto out; switch (po->tp_version) { case TPACKET_V1: po->tp_hdrlen = TPACKET_HDRLEN; break; case TPACKET_V2: po->tp_hdrlen = TPACKET2_HDRLEN; break; case TPACKET_V3: po->tp_hdrlen = TPACKET3_HDRLEN; break; } err = -EINVAL; if (unlikely((int)req->tp_block_size <= 0)) goto out; if (unlikely(req->tp_block_size & (PAGE_SIZE - 1))) goto out; if (unlikely(req->tp_frame_size < po->tp_hdrlen + po->tp_reserve)) goto out; if (unlikely(req->tp_frame_size & (TPACKET_ALIGNMENT - 1))) goto out; rb->frames_per_block = req->tp_block_size/req->tp_frame_size; if (unlikely(rb->frames_per_block <= 0)) goto out; if (unlikely((rb->frames_per_block * req->tp_block_nr) != req->tp_frame_nr)) goto out; err = -ENOMEM; order = get_order(req->tp_block_size); pg_vec = alloc_pg_vec(req, order); if (unlikely(!pg_vec)) goto out; switch (po->tp_version) { case TPACKET_V3: /* Transmit path is not supported. We checked * it above but just being paranoid */ if (!tx_ring) init_prb_bdqc(po, rb, pg_vec, req_u, tx_ring); break; default: break; } } /* Done */ else { err = -EINVAL; if (unlikely(req->tp_frame_nr)) goto out; } lock_sock(sk); /* Detach socket from network */ spin_lock(&po->bind_lock); was_running = po->running; num = po->num; if (was_running) { po->num = 0; __unregister_prot_hook(sk, false); } spin_unlock(&po->bind_lock); synchronize_net(); err = -EBUSY; mutex_lock(&po->pg_vec_lock); if (closing || atomic_read(&po->mapped) == 0) { err = 0; spin_lock_bh(&rb_queue->lock); swap(rb->pg_vec, pg_vec); rb->frame_max = (req->tp_frame_nr - 1); rb->head = 0; rb->frame_size = req->tp_frame_size; spin_unlock_bh(&rb_queue->lock); swap(rb->pg_vec_order, order); swap(rb->pg_vec_len, req->tp_block_nr); rb->pg_vec_pages = req->tp_block_size/PAGE_SIZE; po->prot_hook.func = (po->rx_ring.pg_vec) ? tpacket_rcv : packet_rcv; skb_queue_purge(rb_queue); if (atomic_read(&po->mapped)) pr_err("packet_mmap: vma is busy: %d\n", atomic_read(&po->mapped)); } mutex_unlock(&po->pg_vec_lock); spin_lock(&po->bind_lock); if (was_running) { po->num = num; register_prot_hook(sk); } spin_unlock(&po->bind_lock); if (closing && (po->tp_version > TPACKET_V2)) { /* Because we don't support block-based V3 on tx-ring */ if (!tx_ring) prb_shutdown_retire_blk_timer(po, tx_ring, rb_queue); } release_sock(sk); if (pg_vec) free_pg_vec(pg_vec, order, req->tp_block_nr); out: return err; } static int packet_mmap(struct file *file, struct socket *sock, struct vm_area_struct *vma) { struct sock *sk = sock->sk; struct packet_sock *po = pkt_sk(sk); unsigned long size, expected_size; struct packet_ring_buffer *rb; unsigned long start; int err = -EINVAL; int i; if (vma->vm_pgoff) return -EINVAL; mutex_lock(&po->pg_vec_lock); expected_size = 0; for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) { if (rb->pg_vec) { expected_size += rb->pg_vec_len * rb->pg_vec_pages * PAGE_SIZE; } } if (expected_size == 0) goto out; size = vma->vm_end - vma->vm_start; if (size != expected_size) goto out; start = vma->vm_start; for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) { if (rb->pg_vec == NULL) continue; for (i = 0; i < rb->pg_vec_len; i++) { struct page *page; void *kaddr = rb->pg_vec[i].buffer; int pg_num; for (pg_num = 0; pg_num < rb->pg_vec_pages; pg_num++) { page = pgv_to_page(kaddr); err = vm_insert_page(vma, start, page); if (unlikely(err)) goto out; start += PAGE_SIZE; kaddr += PAGE_SIZE; } } } atomic_inc(&po->mapped); vma->vm_ops = &packet_mmap_ops; err = 0; out: mutex_unlock(&po->pg_vec_lock); return err; }


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