/*
* Copyright (C) ST-Ericsson AB 2010
* Author: Sjur Brendeland/sjur.brandeland@stericsson.com
* License terms: GNU General Public License (GPL) version 2
*/
#include <linux/string.h>
#include <linux/skbuff.h>
#include <linux/hardirq.h>
#include <net/caif/cfpkt.h>
#define PKT_PREFIX CAIF_NEEDED_HEADROOM
#define PKT_POSTFIX CAIF_NEEDED_TAILROOM
#define PKT_LEN_WHEN_EXTENDING 128
#define PKT_ERROR(pkt, errmsg) do { \
cfpkt_priv(pkt)->erronous = true; \
skb_reset_tail_pointer(&pkt->skb); \
pr_warning("CAIF: " errmsg);\
} while (0)
struct cfpktq {
struct sk_buff_head head;
atomic_t count;
/* Lock protects count updates */
spinlock_t lock;
};
/*
* net/caif/ is generic and does not
* understand SKB, so we do this typecast
*/
struct cfpkt {
struct sk_buff skb;
};
/* Private data inside SKB */
struct cfpkt_priv_data {
struct dev_info dev_info;
bool erronous;
};
inline struct cfpkt_priv_data *cfpkt_priv(struct cfpkt *pkt)
{
return (struct cfpkt_priv_data *) pkt->skb.cb;
}
inline bool is_erronous(struct cfpkt *pkt)
{
return cfpkt_priv(pkt)->erronous;
}
inline struct sk_buff *pkt_to_skb(struct cfpkt *pkt)
{
return &pkt->skb;
}
inline struct cfpkt *skb_to_pkt(struct sk_buff *skb)
{
return (struct cfpkt *) skb;
}
struct cfpkt *cfpkt_fromnative(enum caif_direction dir, void *nativepkt)
{
struct cfpkt *pkt = skb_to_pkt(nativepkt);
cfpkt_priv(pkt)->erronous = false;
return pkt;
}
EXPORT_SYMBOL(cfpkt_fromnative);
void *cfpkt_tonative(struct cfpkt *pkt)
{
return (void *) pkt;
}
EXPORT_SYMBOL(cfpkt_tonative);
static struct cfpkt *cfpkt_create_pfx(u16 len, u16 pfx)
{
struct sk_buff *skb;
if (likely(in_interrupt()))
skb = alloc_skb(len + pfx, GFP_ATOMIC);
else
skb = alloc_skb(len + pfx, GFP_KERNEL);
if (unlikely(skb == NULL))
return NULL;
skb_reserve(skb, pfx);
return skb_to_pkt(skb);
}
inline struct cfpkt *cfpkt_create(u16 len)
{
return cfpkt_create_pfx(len + PKT_POSTFIX, PKT_PREFIX);
}
EXPORT_SYMBOL(cfpkt_create);
void cfpkt_destroy(struct cfpkt *pkt)
{
struct sk_buff *skb = pkt_to_skb(pkt);
kfree_skb(skb);
}
EXPORT_SYMBOL(cfpkt_destroy);
inline bool cfpkt_more(struct cfpkt *pkt)
{
struct sk_buff *skb = pkt_to_skb(pkt);
return skb->len > 0;
}
EXPORT_SYMBOL(cfpkt_more);
int cfpkt_peek_head(struct cfpkt *pkt, void *data, u16 len)
{
struct sk_buff *skb = pkt_to_skb(pkt);
if (skb_headlen(skb) >= len) {
memcpy(data, skb->data, len);
return 0;
}
return !cfpkt_extr_head(pkt, data, len) &&
!cfpkt_add_head(pkt, data, len);
}
EXPORT_SYMBOL(cfpkt_peek_head);
int cfpkt_extr_head(struct cfpkt *pkt, void *data, u16 len)
{
struct sk_buff *skb = pkt_to_skb(pkt);
u8 *from;
if (unlikely(is_erronous(pkt)))
return -EPROTO;
if (unlikely(len > skb->len)) {
PKT_ERROR(pkt, "cfpkt_extr_head read beyond end of packet\n");
return -EPROTO;
}
if (unlikely(len > skb_headlen(skb))) {
if (unlikely(skb_linearize(skb) != 0)) {
PKT_ERROR(pkt, "cfpkt_extr_head linearize failed\n");
return -EPROTO;
}
}
from = skb_pull(skb, len);
from -= len;
memcpy(data, from, len);
return 0;
}
EXPORT_SYMBOL(cfpkt_extr_head);
int cfpkt_extr_trail(struct cfpkt *pkt, void *dta, u16 len)
{
struct sk_buff *skb = pkt_to_skb(pkt);
u8 *data = dta;
u8 *from;
if (unlikely(is_erronous(pkt)))
return -EPROTO;
if (unlikely(skb_linearize(skb) != 0)) {
PKT_ERROR(pkt, "cfpkt_extr_trail linearize failed\n");
return -EPROTO;
}
if (unlikely(skb->data + len > skb_tail_pointer(skb))) {
PKT_ERROR(pkt, "cfpkt_extr_trail read beyond end of packet\n");
return -EPROTO;
}
from = skb_tail_pointer(skb) - len;
skb_trim(skb, skb->len - len);
memcpy(data, from, len);
return 0;
}
EXPORT_SYMBOL(cfpkt_extr_trail);
int cfpkt_pad_trail(struct cfpkt *pkt, u16 len)
{
return cfpkt_add_body(pkt, NULL, len);
}
EXPORT_SYMBOL(cfpkt_pad_trail);
int cfpkt_add_body(struct cfpkt *pkt, const void *data, u16 len)
{
struct sk_buff *skb = pkt_to_skb(pkt);
struct sk_buff *lastskb;
u8 *to;
u16 addlen = 0;
if (unlikely(is_erronous(pkt)))
return -EPROTO;
lastskb = skb;
/* Check whether we need to add space at the tail */
if (unlikely(skb_tailroom(skb) < len)) {
if (likely(len < PKT_LEN_WHEN_EXTENDING))
addlen = PKT_LEN_WHEN_EXTENDING;
else
addlen = len;
}
/* Check whether we need to change the SKB before writing to the tail */
if (unlikely((addlen > 0) || skb_cloned(skb) || skb_shared(skb))) {
/* Make sure data is writable */
if (unlikely(skb_cow_data(skb, addlen, &lastskb) < 0)) {
PKT_ERROR(pkt, "cfpkt_add_body: cow failed\n");
return -EPROTO;
}
/*
* Is the SKB non-linear after skb_cow_data()? If so, we are
* going to add data to the last SKB, so we need to adjust
* lengths of the top SKB.
*/
if (lastskb != skb) {
pr_warning("CAIF: %s(): Packet is non-linear\n",
__func__);
skb->len += len;
skb->data_len += len;
}
}
/* All set to put the last SKB and optionally write data there. */
to = skb_put(lastskb, len);
if (likely(data))
memcpy(to, data, len);
return 0;
}
EXPORT_SYMBOL(cfpkt_add_body);
inline int cfpkt_addbdy(struct cfpkt *pkt, u8 data)
{
return cfpkt_add_body(pkt, &data, 1);
}
EXPORT_SYMBOL(cfpkt_addbdy);
int cfpkt_add_head(struct cfpkt *pkt, const void *data2, u16 len)
{
struct sk_buff *skb = pkt_to_skb(pkt);
struct sk_buff *lastskb;
u8 *to;
const u8 *data = data2;
if (unlikely(is_erronous(pkt)))
return -EPROTO;
if (unlikely(skb_headroom(skb) < len)) {
PKT_ERROR(pkt, "cfpkt_add_head: no headroom\n");
return -EPROTO;
}
/* Make sure data is writable */
if (unlikely(skb_cow_data(skb, 0, &lastskb) < 0)) {
PKT_ERROR(pkt, "cfpkt_add_head: cow failed\n");
return -EPROTO;
}
to = skb_push(skb, len);
memcpy(to, data, len);
return 0;
}
EXPORT_SYMBOL(cfpkt_add_head);
inline int cfpkt_add_trail(struct cfpkt *pkt, const void *data, u16 len)
{
return cfpkt_add_body(pkt, data, len);
}
EXPORT_SYMBOL(cfpkt_add_trail);
inline u16 cfpkt_getlen(struct cfpkt *pkt)
{
struct sk_buff *skb = pkt_to_skb(pkt);
return skb->len;
}
EXPORT_SYMBOL(cfpkt_getlen);
inline u16 cfpkt_iterate(struct cfpkt *pkt,
u16 (*iter_func)(u16, void *, u16),
u16 data)
{
/*
* Don't care about the performance hit of linearizing,
* Checksum should not be used on high-speed interfaces anyway.
*/
if (unlikely(is_erronous(pkt)))
return -EPROTO;
if (unlikely(skb_linearize(&pkt->skb) != 0)) {
PKT_ERROR(pkt, "cfpkt_iterate: linearize failed\n");
return -EPROTO;
}
return iter_func(data, pkt->skb.data, cfpkt_getlen(pkt));
}
EXPORT_SYMBOL(cfpkt_iterate);
int cfpkt_setlen(struct cfpkt *pkt, u16 len)
{
struct sk_buff *skb = pkt_to_skb(pkt);
if (unlikely(is_erronous(pkt)))
return -EPROTO;
if (likely(len <= skb->len)) {
if (unlikely(skb->data_len))
___pskb_trim(skb, len);
else
skb_trim(skb, len);
return cfpkt_getlen(pkt);
}
/* Need to expand SKB */
if (unlikely(!cfpkt_pad_trail(pkt, len - skb->len)))
PKT_ERROR(pkt, "cfpkt_setlen: skb_pad_trail failed\n");
return cfpkt_getlen(pkt);
}
EXPORT_SYMBOL(cfpkt_setlen);
struct cfpkt *cfpkt_create_uplink(const unsigned char *data, unsigned int len)
{
struct cfpkt *pkt = cfpkt_create_pfx(len + PKT_POSTFIX, PKT_PREFIX);
if (unlikely(data != NULL))
cfpkt_add_body(pkt, data, len);
return pkt;
}
EXPORT_SYMBOL(cfpkt_create_uplink);
struct cfpkt *cfpkt_append(struct cfpkt *dstpkt,
struct cfpkt *addpkt,
u16 expectlen)
{
struct sk_buff *dst = pkt_to_skb(dstpkt);
struct sk_buff *add = pkt_to_skb(addpkt);
u16 addlen = skb_headlen(add);
u16 neededtailspace;
struct sk_buff *tmp;
u16 dstlen;
u16 createlen;
if (unlikely(is_erronous(dstpkt) || is_erronous(addpkt))) {
cfpkt_destroy(addpkt);
return dstpkt;
}
if (expectlen > addlen)
neededtailspace = expectlen;
else
neededtailspace = addlen;
if (dst->tail + neededtailspace > dst->end) {
/* Create a dumplicate of 'dst' with more tail space */
dstlen = skb_headlen(dst);
createlen = dstlen + neededtailspace;
tmp = pkt_to_skb(
cfpkt_create(createlen + PKT_PREFIX + PKT_POSTFIX));
if (!tmp)
return NULL;
skb_set_tail_pointer(tmp, dstlen);
tmp->len = dstlen;
memcpy(tmp->data, dst->data, dstlen);
cfpkt_destroy(dstpkt);
dst = tmp;
}
memcpy(skb_tail_pointer(dst), add->data, skb_headlen(add));
cfpkt_destroy(addpkt);
dst->tail += addlen;
dst->len += addlen;
return skb_to_pkt(dst);
}
EXPORT_SYMBOL(cfpkt_append);
struct cfpkt *cfpkt_split(struct cfpkt *pkt, u16 pos)
{
struct sk_buff *skb2;
struct sk_buff *skb = pkt_to_skb(pkt);
u8 *split = skb->data + pos;
u16 len2nd = skb_tail_pointer(skb) - split;
if (unlikely(is_erronous(pkt)))
return NULL;
if (skb->data + pos > skb_tail_pointer(skb)) {
PKT_ERROR(pkt,
"cfpkt_split: trying to split beyond end of packet");
return NULL;
}
/* Create a new packet for the second part of the data */
skb2 = pkt_to_skb(
cfpkt_create_pfx(len2nd + PKT_PREFIX + PKT_POSTFIX,
PKT_PREFIX));
if (skb2 == NULL)
return NULL;
/* Reduce the length of the original packet */
skb_set_tail_pointer(skb, pos);
skb->len = pos;
memcpy(skb2->data, split, len2nd);
skb2->tail += len2nd;
skb2->len += len2nd;
return skb_to_pkt(skb2);
}
EXPORT_SYMBOL(cfpkt_split);
char *cfpkt_log_pkt(struct cfpkt *pkt, char *buf, int buflen)
{
struct sk_buff *skb = pkt_to_skb(pkt);
char *p = buf;
int i;
/*
* Sanity check buffer length, it needs to be at least as large as
* the header info: ~=50+ bytes
*/
if (buflen < 50)
return NULL;
snprintf(buf, buflen, "%s: pkt:%p len:%ld(%ld+%ld) {%ld,%ld} data: [",
is_erronous(pkt) ? "ERRONOUS-SKB" :
(skb->data_len != 0 ? "COMPLEX-SKB" : "SKB"),
skb,
(long) skb->len,
(long) (skb_tail_pointer(skb) - skb->data),
(long) skb->data_len,
(long) (skb->data - skb->head),
(long) (skb_tail_pointer(skb) - skb->head));
p = buf + strlen(buf);
for (i = 0; i < skb_tail_pointer(skb) - skb->data && i < 300; i++) {
if (p > buf + buflen - 10) {
sprintf(p, "...");
p = buf + strlen(buf);
break;
}
sprintf(p, "%02x,", skb->data[i]);
p = buf + strlen(buf);
}
sprintf(p, "]\n");
return buf;
}
EXPORT_SYMBOL(cfpkt_log_pkt);
int cfpkt_raw_append(struct cfpkt *pkt, void **buf, unsigned int buflen)
{
struct sk_buff *skb = pkt_to_skb(pkt);
struct sk_buff *lastskb;
caif_assert(buf != NULL);
if (unlikely(is_erronous(pkt)))
return -EPROTO;
/* Make sure SKB is writable */
if (unlikely(skb_cow_data(skb, 0, &lastskb) < 0)) {
PKT_ERROR(pkt, "cfpkt_raw_append: skb_cow_data failed\n");
return -EPROTO;
}
if (unlikely(skb_linearize(skb) != 0)) {
PKT_ERROR(pkt, "cfpkt_raw_append: linearize failed\n");
return -EPROTO;
}
if (unlikely(skb_tailroom(skb) < buflen)) {
PKT_ERROR(pkt, "cfpkt_raw_append: buffer too short - failed\n");
return -EPROTO;
}
*buf = skb_put(skb, buflen);
return 1;
}
EXPORT_SYMBOL(cfpkt_raw_append);
int cfpkt_raw_extract(struct cfpkt *pkt, void **buf, unsigned int buflen)
{
struct sk_buff *skb = pkt_to_skb(pkt);
caif_assert(buf != NULL);
if (unlikely(is_erronous(pkt)))
return -EPROTO;
if (unlikely(buflen > skb->len)) {
PKT_ERROR(pkt, "cfpkt_raw_extract: buflen too large "
"- failed\n");
return -EPROTO;
}
if (unlikely(buflen > skb_headlen(skb))) {
if (unlikely(skb_linearize(skb) != 0)) {
PKT_ERROR(pkt, "cfpkt_raw_extract: linearize failed\n");
return -EPROTO;
}
}
*buf = skb->data;
skb_pull(skb, buflen);
return 1;
}
EXPORT_SYMBOL(cfpkt_raw_extract);
inline bool cfpkt_erroneous(struct cfpkt *pkt)
{
return cfpkt_priv(pkt)->erronous;
}
EXPORT_SYMBOL(cfpkt_erroneous);
struct cfpktq *cfpktq_create(void)
{
struct cfpktq *q = kmalloc(sizeof(struct cfpktq), GFP_ATOMIC);
if (!q)
return NULL;
skb_queue_head_init(&q->head);
atomic_set(&q->count, 0);
spin_lock_init(&q->lock);
return q;
}
EXPORT_SYMBOL(cfpktq_create);
void cfpkt_queue(struct cfpktq *pktq, struct cfpkt *pkt, unsigned short prio)
{
atomic_inc(&pktq->count);
spin_lock(&pktq->lock);
skb_queue_tail(&pktq->head, pkt_to_skb(pkt));
spin_unlock(&pktq->lock);
}
EXPORT_SYMBOL(cfpkt_queue);
struct cfpkt *cfpkt_qpeek(struct cfpktq *pktq)
{
struct cfpkt *tmp;
spin_lock(&pktq->lock);
tmp = skb_to_pkt(skb_peek(&pktq->head));
spin_unlock(&pktq->lock);
return tmp;
}
EXPORT_SYMBOL(cfpkt_qpeek);
struct cfpkt *cfpkt_dequeue(struct cfpktq *pktq)
{
struct cfpkt *pkt;
spin_lock(&pktq->lock);
pkt = skb_to_pkt(skb_dequeue(&pktq->head));
if (pkt) {
atomic_dec(&pktq->count);
caif_assert(atomic_read(&pktq->count) >= 0);
}
spin_unlock(&pktq->lock);
return pkt;
}
EXPORT_SYMBOL(cfpkt_dequeue);
int cfpkt_qcount(struct cfpktq *pktq)
{
return atomic_read(&pktq->count);
}
EXPORT_SYMBOL(cfpkt_qcount);
struct cfpkt *cfpkt_clone_release(struct cfpkt *pkt)
{
struct cfpkt *clone;
clone = skb_to_pkt(skb_clone(pkt_to_skb(pkt), GFP_ATOMIC));
/* Free original packet. */
cfpkt_destroy(pkt);
if (!clone)
return NULL;
return clone;
}
EXPORT_SYMBOL(cfpkt_clone_release);
struct caif_payload_info *cfpkt_info(struct cfpkt *pkt)
{
return (struct caif_payload_info *)&pkt_to_skb(pkt)->cb;
}
EXPORT_SYMBOL(cfpkt_info);
