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

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Diffstat (limited to 'net/tipc')

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/* SCTP kernel implementation * (C) Copyright IBM Corp. 2001, 2004 * Copyright (c) 1999-2000 Cisco, Inc. * Copyright (c) 1999-2001 Motorola, Inc. * * This file is part of the SCTP kernel implementation * * These functions handle output processing. * * This SCTP implementation 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, or (at your option) * any later version. * * This SCTP implementation is distributed in the hope that it * will be useful, but WITHOUT ANY WARRANTY; without even the implied * ************************ * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. * See the GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with GNU CC; see the file COPYING. If not, see * <http://www.gnu.org/licenses/>. * * Please send any bug reports or fixes you make to the * email address(es): * lksctp developers <linux-sctp@vger.kernel.org> * * Written or modified by: * La Monte H.P. Yarroll <piggy@acm.org> * Karl Knutson <karl@athena.chicago.il.us> * Jon Grimm <jgrimm@austin.ibm.com> * Sridhar Samudrala <sri@us.ibm.com> */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include <linux/types.h> #include <linux/kernel.h> #include <linux/wait.h> #include <linux/time.h> #include <linux/ip.h> #include <linux/ipv6.h> #include <linux/init.h> #include <linux/slab.h> #include <net/inet_ecn.h> #include <net/ip.h> #include <net/icmp.h> #include <net/net_namespace.h> #include <linux/socket.h> /* for sa_family_t */ #include <net/sock.h> #include <net/sctp/sctp.h> #include <net/sctp/sm.h> #include <net/sctp/checksum.h> /* Forward declarations for private helpers. */ static sctp_xmit_t __sctp_packet_append_chunk(struct sctp_packet *packet, struct sctp_chunk *chunk); static sctp_xmit_t sctp_packet_can_append_data(struct sctp_packet *packet, struct sctp_chunk *chunk); static void sctp_packet_append_data(struct sctp_packet *packet, struct sctp_chunk *chunk); static sctp_xmit_t sctp_packet_will_fit(struct sctp_packet *packet, struct sctp_chunk *chunk, u16 chunk_len); static void sctp_packet_reset(struct sctp_packet *packet) { packet->size = packet->overhead; packet->has_cookie_echo = 0; packet->has_sack = 0; packet->has_data = 0; packet->has_auth = 0; packet->ipfragok = 0; packet->auth = NULL; } /* Config a packet. * This appears to be a followup set of initializations. */ void sctp_packet_config(struct sctp_packet *packet, __u32 vtag, int ecn_capable) { struct sctp_transport *tp = packet->transport; struct sctp_association *asoc = tp->asoc; pr_debug("%s: packet:%p vtag:0x%x\n", __func__, packet, vtag); packet->vtag = vtag; if (asoc && tp->dst) { struct sock *sk = asoc->base.sk; rcu_read_lock(); if (__sk_dst_get(sk) != tp->dst) { dst_hold(tp->dst); sk_setup_caps(sk, tp->dst); } if (sk_can_gso(sk)) { struct net_device *dev = tp->dst->dev; packet->max_size = dev->gso_max_size; } else { packet->max_size = asoc->pathmtu; } rcu_read_unlock(); } else { packet->max_size = tp->pathmtu; } if (ecn_capable && sctp_packet_empty(packet)) { struct sctp_chunk *chunk; /* If there a is a prepend chunk stick it on the list before * any other chunks get appended. */ chunk = sctp_get_ecne_prepend(asoc); if (chunk) sctp_packet_append_chunk(packet, chunk); } } /* Initialize the packet structure. */ void sctp_packet_init(struct sctp_packet *packet, struct sctp_transport *transport, __u16 sport, __u16 dport) { struct sctp_association *asoc = transport->asoc; size_t overhead; pr_debug("%s: packet:%p transport:%p\n", __func__, packet, transport); packet->transport = transport; packet->source_port = sport; packet->destination_port = dport; INIT_LIST_HEAD(&packet->chunk_list); if (asoc) { struct sctp_sock *sp = sctp_sk(asoc->base.sk); overhead = sp->pf->af->net_header_len; } else { overhead = sizeof(struct ipv6hdr); } overhead += sizeof(struct sctphdr); packet->overhead = overhead; sctp_packet_reset(packet); packet->vtag = 0; } /* Free a packet. */ void sctp_packet_free(struct sctp_packet *packet) { struct sctp_chunk *chunk, *tmp; pr_debug("%s: packet:%p\n", __func__, packet); list_for_each_entry_safe(chunk, tmp, &packet->chunk_list, list) { list_del_init(&chunk->list); sctp_chunk_free(chunk); } } /* This routine tries to append the chunk to the offered packet. If adding * the chunk causes the packet to exceed the path MTU and COOKIE_ECHO chunk * is not present in the packet, it transmits the input packet. * Data can be bundled with a packet containing a COOKIE_ECHO chunk as long * as it can fit in the packet, but any more data that does not fit in this * packet can be sent only after receiving the COOKIE_ACK. */ sctp_xmit_t sctp_packet_transmit_chunk(struct sctp_packet *packet, struct sctp_chunk *chunk, int one_packet, gfp_t gfp) { sctp_xmit_t retval; pr_debug("%s: packet:%p size:%zu chunk:%p size:%d\n", __func__, packet, packet->size, chunk, chunk->skb ? chunk->skb->len : -1); switch ((retval = (sctp_packet_append_chunk(packet, chunk)))) { case SCTP_XMIT_PMTU_FULL: if (!packet->has_cookie_echo) { int error = 0; error = sctp_packet_transmit(packet, gfp); if (error < 0) chunk->skb->sk->sk_err = -error; /* If we have an empty packet, then we can NOT ever * return PMTU_FULL. */ if (!one_packet) retval = sctp_packet_append_chunk(packet, chunk); } break; case SCTP_XMIT_RWND_FULL: case SCTP_XMIT_OK: case SCTP_XMIT_DELAY: break; } return retval; } /* Try to bundle an auth chunk into the packet. */ static sctp_xmit_t sctp_packet_bundle_auth(struct sctp_packet *pkt, struct sctp_chunk *chunk) { struct sctp_association *asoc = pkt->transport->asoc; struct sctp_chunk *auth; sctp_xmit_t retval = SCTP_XMIT_OK; /* if we don't have an association, we can't do authentication */ if (!asoc) return retval; /* See if this is an auth chunk we are bundling or if * auth is already bundled. */ if (chunk->chunk_hdr->type == SCTP_CID_AUTH || pkt->has_auth) return retval; /* if the peer did not request this chunk to be authenticated, * don't do it */ if (!chunk->auth) return retval; auth = sctp_make_auth(asoc); if (!auth) return retval; retval = __sctp_packet_append_chunk(pkt, auth); if (retval != SCTP_XMIT_OK) sctp_chunk_free(auth); return retval; } /* Try to bundle a SACK with the packet. */ static sctp_xmit_t sctp_packet_bundle_sack(struct sctp_packet *pkt, struct sctp_chunk *chunk) { sctp_xmit_t retval = SCTP_XMIT_OK; /* If sending DATA and haven't aleady bundled a SACK, try to * bundle one in to the packet. */ if (sctp_chunk_is_data(chunk) && !pkt->has_sack && !pkt->has_cookie_echo) { struct sctp_association *asoc; struct timer_list *timer; asoc = pkt->transport->asoc; timer = &asoc->timers[SCTP_EVENT_TIMEOUT_SACK]; /* If the SACK timer is running, we have a pending SACK */ if (timer_pending(timer)) { struct sctp_chunk *sack; if (pkt->transport->sack_generation != pkt->transport->asoc->peer.sack_generation) return retval; asoc->a_rwnd = asoc->rwnd; sack = sctp_make_sack(asoc); if (sack) { retval = __sctp_packet_append_chunk(pkt, sack); if (retval != SCTP_XMIT_OK) { sctp_chunk_free(sack); goto out; } asoc->peer.sack_needed = 0; if (del_timer(timer)) sctp_association_put(asoc); } } } out: return retval; } /* Append a chunk to the offered packet reporting back any inability to do * so. */ static sctp_xmit_t __sctp_packet_append_chunk(struct sctp_packet *packet, struct sctp_chunk *chunk) { sctp_xmit_t retval = SCTP_XMIT_OK; __u16 chunk_len = SCTP_PAD4(ntohs(chunk->chunk_hdr->length)); /* Check to see if this chunk will fit into the packet */ retval = sctp_packet_will_fit(packet, chunk, chunk_len); if (retval != SCTP_XMIT_OK) goto finish; /* We believe that this chunk is OK to add to the packet */ switch (chunk->chunk_hdr->type) { case SCTP_CID_DATA: /* Account for the data being in the packet */ sctp_packet_append_data(packet, chunk); /* Disallow SACK bundling after DATA. */ packet->has_sack = 1; /* Disallow AUTH bundling after DATA */ packet->has_auth = 1; /* Let it be knows that packet has DATA in it */ packet->has_data = 1; /* timestamp the chunk for rtx purposes */ chunk->sent_at = jiffies; /* Mainly used for prsctp RTX policy */ chunk->sent_count++; break; case SCTP_CID_COOKIE_ECHO: packet->has_cookie_echo = 1; break; case SCTP_CID_SACK: packet->has_sack = 1; if (chunk->asoc) chunk->asoc->stats.osacks++; break; case SCTP_CID_AUTH: packet->has_auth = 1; packet->auth = chunk; break; } /* It is OK to send this chunk. */ list_add_tail(&chunk->list, &packet->chunk_list); packet->size += chunk_len; chunk->transport = packet->transport; finish: return retval; } /* Append a chunk to the offered packet reporting back any inability to do * so. */ sctp_xmit_t sctp_packet_append_chunk(struct sctp_packet *packet, struct sctp_chunk *chunk) { sctp_xmit_t retval = SCTP_XMIT_OK; pr_debug("%s: packet:%p chunk:%p\n", __func__, packet, chunk); /* Data chunks are special. Before seeing what else we can * bundle into this packet, check to see if we are allowed to * send this DATA. */ if (sctp_chunk_is_data(chunk)) { retval = sctp_packet_can_append_data(packet, chunk); if (retval != SCTP_XMIT_OK) goto finish; } /* Try to bundle AUTH chunk */ retval = sctp_packet_bundle_auth(packet, chunk); if (retval != SCTP_XMIT_OK) goto finish; /* Try to bundle SACK chunk */ retval = sctp_packet_bundle_sack(packet, chunk); if (retval != SCTP_XMIT_OK) goto finish; retval = __sctp_packet_append_chunk(packet, chunk); finish: return retval; } static void sctp_packet_release_owner(struct sk_buff *skb) { sk_free(skb->sk); } static void sctp_packet_set_owner_w(struct sk_buff *skb, struct sock *sk) { skb_orphan(skb); skb->sk = sk; skb->destructor = sctp_packet_release_owner; /* * The data chunks have already been accounted for in sctp_sendmsg(), * therefore only reserve a single byte to keep socket around until * the packet has been transmitted. */ atomic_inc(&sk->sk_wmem_alloc); } static int sctp_packet_pack(struct sctp_packet *packet, struct sk_buff *head, int gso, gfp_t gfp) { struct sctp_transport *tp = packet->transport; struct sctp_auth_chunk *auth = NULL; struct sctp_chunk *chunk, *tmp; int pkt_count = 0, pkt_size; struct sock *sk = head->sk; struct sk_buff *nskb; int auth_len = 0; if (gso) { skb_shinfo(head)->gso_type = sk->sk_gso_type; NAPI_GRO_CB(head)->last = head; } else { nskb = head; pkt_size = packet->size; goto merge; } do { /* calculate the pkt_size and alloc nskb */ pkt_size = packet->overhead; list_for_each_entry_safe(chunk, tmp, &packet->chunk_list, list) { int padded = SCTP_PAD4(chunk->skb->len); if (chunk == packet->auth) auth_len = padded; else if (auth_len + padded + packet->overhead > tp->pathmtu) return 0; else if (pkt_size + padded > tp->pathmtu) break; pkt_size += padded; } nskb = alloc_skb(pkt_size + MAX_HEADER, gfp); if (!nskb) return 0; skb_reserve(nskb, packet->overhead + MAX_HEADER); merge: /* merge chunks into nskb and append nskb into head list */ pkt_size -= packet->overhead; list_for_each_entry_safe(chunk, tmp, &packet->chunk_list, list) { int padding; list_del_init(&chunk->list); if (sctp_chunk_is_data(chunk)) { if (!sctp_chunk_retransmitted(chunk) && !tp->rto_pending) { chunk->rtt_in_progress = 1; tp->rto_pending = 1; } } padding = SCTP_PAD4(chunk->skb->len) - chunk->skb->len; if (padding) memset(skb_put(chunk->skb, padding), 0, padding); if (chunk == packet->auth) auth = (struct sctp_auth_chunk *) skb_tail_pointer(nskb); memcpy(skb_put(nskb, chunk->skb->len), chunk->skb->data, chunk->skb->len); pr_debug("*** Chunk:%p[%s] %s 0x%x, length:%d, chunk->skb->len:%d, rtt_in_progress:%d\n", chunk, sctp_cname(SCTP_ST_CHUNK(chunk->chunk_hdr->type)), chunk->has_tsn ? "TSN" : "No TSN", chunk->has_tsn ? ntohl(chunk->subh.data_hdr->tsn) : 0, ntohs(chunk->chunk_hdr->length), chunk->skb->len, chunk->rtt_in_progress); pkt_size -= SCTP_PAD4(chunk->skb->len); if (!sctp_chunk_is_data(chunk) && chunk != packet->auth) sctp_chunk_free(chunk); if (!pkt_size) break; } if (auth) { sctp_auth_calculate_hmac(tp->asoc, nskb, auth, gfp); /* free auth if no more chunks, or add it back */ if (list_empty(&packet->chunk_list)) sctp_chunk_free(packet->auth); else list_add(&packet->auth->list, &packet->chunk_list); } if (gso) { if (skb_gro_receive(&head, nskb)) { kfree_skb(nskb); return 0; } if (WARN_ON_ONCE(skb_shinfo(head)->gso_segs >= sk->sk_gso_max_segs)) return 0; } pkt_count++; } while (!list_empty(&packet->chunk_list)); if (gso) { memset(head->cb, 0, max(sizeof(struct inet_skb_parm), sizeof(struct inet6_skb_parm))); skb_shinfo(head)->gso_segs = pkt_count; skb_shinfo(head)->gso_size = GSO_BY_FRAGS; rcu_read_lock(); if (skb_dst(head) != tp->dst) { dst_hold(tp->dst); sk_setup_caps(sk, tp->dst); } rcu_read_unlock(); goto chksum; } if (sctp_checksum_disable) return 1; if (!(skb_dst(head)->dev->features & NETIF_F_SCTP_CRC) || dst_xfrm(skb_dst(head)) || packet->ipfragok) { struct sctphdr *sh = (struct sctphdr *)skb_transport_header(head); sh->checksum = sctp_compute_cksum(head, 0); } else { chksum: head->ip_summed = CHECKSUM_PARTIAL; head->csum_start = skb_transport_header(head) - head->head; head->csum_offset = offsetof(struct sctphdr, checksum); } return pkt_count; } /* All packets are sent to the network through this function from * sctp_outq_tail(). * * The return value is always 0 for now. */ int sctp_packet_transmit(struct sctp_packet *packet, gfp_t gfp) { struct sctp_transport *tp = packet->transport; struct sctp_association *asoc = tp->asoc; struct sctp_chunk *chunk, *tmp; int pkt_count, gso = 0; int confirm; struct dst_entry *dst; struct sk_buff *head; struct sctphdr *sh;


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