383 lines
8.1 KiB
C
383 lines
8.1 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/*
|
|
* Copyright (C) ST-Ericsson AB 2010
|
|
* Author: Sjur Brendeland
|
|
*/
|
|
|
|
#define pr_fmt(fmt) KBUILD_MODNAME ":%s(): " fmt, __func__
|
|
|
|
#include <linux/string.h>
|
|
#include <linux/skbuff.h>
|
|
#include <linux/export.h>
|
|
#include <net/caif/cfpkt.h>
|
|
|
|
#define PKT_PREFIX 48
|
|
#define PKT_POSTFIX 2
|
|
#define PKT_LEN_WHEN_EXTENDING 128
|
|
#define PKT_ERROR(pkt, errmsg) \
|
|
do { \
|
|
cfpkt_priv(pkt)->erronous = true; \
|
|
skb_reset_tail_pointer(&pkt->skb); \
|
|
pr_warn(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;
|
|
};
|
|
|
|
static inline struct cfpkt_priv_data *cfpkt_priv(struct cfpkt *pkt)
|
|
{
|
|
return (struct cfpkt_priv_data *) pkt->skb.cb;
|
|
}
|
|
|
|
static inline bool is_erronous(struct cfpkt *pkt)
|
|
{
|
|
return cfpkt_priv(pkt)->erronous;
|
|
}
|
|
|
|
static inline struct sk_buff *pkt_to_skb(struct cfpkt *pkt)
|
|
{
|
|
return &pkt->skb;
|
|
}
|
|
|
|
static 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;
|
|
|
|
skb = alloc_skb(len + pfx, GFP_ATOMIC);
|
|
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);
|
|
}
|
|
|
|
void cfpkt_destroy(struct cfpkt *pkt)
|
|
{
|
|
struct sk_buff *skb = pkt_to_skb(pkt);
|
|
kfree_skb(skb);
|
|
}
|
|
|
|
inline bool cfpkt_more(struct cfpkt *pkt)
|
|
{
|
|
struct sk_buff *skb = pkt_to_skb(pkt);
|
|
return skb->len > 0;
|
|
}
|
|
|
|
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);
|
|
}
|
|
|
|
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, "read beyond end of packet\n");
|
|
return -EPROTO;
|
|
}
|
|
|
|
if (unlikely(len > skb_headlen(skb))) {
|
|
if (unlikely(skb_linearize(skb) != 0)) {
|
|
PKT_ERROR(pkt, "linearize failed\n");
|
|
return -EPROTO;
|
|
}
|
|
}
|
|
from = skb_pull(skb, len);
|
|
from -= len;
|
|
if (data)
|
|
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, "linearize failed\n");
|
|
return -EPROTO;
|
|
}
|
|
if (unlikely(skb->data + len > skb_tail_pointer(skb))) {
|
|
PKT_ERROR(pkt, "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;
|
|
}
|
|
|
|
int cfpkt_pad_trail(struct cfpkt *pkt, u16 len)
|
|
{
|
|
return cfpkt_add_body(pkt, NULL, len);
|
|
}
|
|
|
|
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, "cow failed\n");
|
|
return -EPROTO;
|
|
}
|
|
}
|
|
|
|
/* All set to put the last SKB and optionally write data there. */
|
|
to = pskb_put(skb, lastskb, len);
|
|
if (likely(data))
|
|
memcpy(to, data, len);
|
|
return 0;
|
|
}
|
|
|
|
inline int cfpkt_addbdy(struct cfpkt *pkt, u8 data)
|
|
{
|
|
return cfpkt_add_body(pkt, &data, 1);
|
|
}
|
|
|
|
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;
|
|
int ret;
|
|
if (unlikely(is_erronous(pkt)))
|
|
return -EPROTO;
|
|
if (unlikely(skb_headroom(skb) < len)) {
|
|
PKT_ERROR(pkt, "no headroom\n");
|
|
return -EPROTO;
|
|
}
|
|
|
|
/* Make sure data is writable */
|
|
ret = skb_cow_data(skb, 0, &lastskb);
|
|
if (unlikely(ret < 0)) {
|
|
PKT_ERROR(pkt, "cow failed\n");
|
|
return ret;
|
|
}
|
|
|
|
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);
|
|
}
|
|
|
|
inline u16 cfpkt_getlen(struct cfpkt *pkt)
|
|
{
|
|
struct sk_buff *skb = pkt_to_skb(pkt);
|
|
return skb->len;
|
|
}
|
|
|
|
int 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, "linearize failed\n");
|
|
return -EPROTO;
|
|
}
|
|
return iter_func(data, pkt->skb.data, cfpkt_getlen(pkt));
|
|
}
|
|
|
|
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, "skb_pad_trail failed\n");
|
|
|
|
return cfpkt_getlen(pkt);
|
|
}
|
|
|
|
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))) {
|
|
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 */
|
|
struct cfpkt *tmppkt;
|
|
dstlen = skb_headlen(dst);
|
|
createlen = dstlen + neededtailspace;
|
|
tmppkt = cfpkt_create(createlen + PKT_PREFIX + PKT_POSTFIX);
|
|
if (tmppkt == NULL)
|
|
return NULL;
|
|
tmp = pkt_to_skb(tmppkt);
|
|
skb_put_data(tmp, dst->data, dstlen);
|
|
cfpkt_destroy(dstpkt);
|
|
dst = tmp;
|
|
}
|
|
skb_put_data(dst, add->data, skb_headlen(add));
|
|
cfpkt_destroy(addpkt);
|
|
return skb_to_pkt(dst);
|
|
}
|
|
|
|
struct cfpkt *cfpkt_split(struct cfpkt *pkt, u16 pos)
|
|
{
|
|
struct sk_buff *skb2;
|
|
struct sk_buff *skb = pkt_to_skb(pkt);
|
|
struct cfpkt *tmppkt;
|
|
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, "trying to split beyond end of packet\n");
|
|
return NULL;
|
|
}
|
|
|
|
/* Create a new packet for the second part of the data */
|
|
tmppkt = cfpkt_create_pfx(len2nd + PKT_PREFIX + PKT_POSTFIX,
|
|
PKT_PREFIX);
|
|
if (tmppkt == NULL)
|
|
return NULL;
|
|
skb2 = pkt_to_skb(tmppkt);
|
|
|
|
|
|
if (skb2 == NULL)
|
|
return NULL;
|
|
|
|
skb_put_data(skb2, split, len2nd);
|
|
|
|
/* Reduce the length of the original packet */
|
|
skb_trim(skb, pos);
|
|
|
|
skb2->priority = skb->priority;
|
|
return skb_to_pkt(skb2);
|
|
}
|
|
|
|
bool cfpkt_erroneous(struct cfpkt *pkt)
|
|
{
|
|
return cfpkt_priv(pkt)->erronous;
|
|
}
|
|
|
|
struct caif_payload_info *cfpkt_info(struct cfpkt *pkt)
|
|
{
|
|
return (struct caif_payload_info *)&pkt_to_skb(pkt)->cb;
|
|
}
|
|
EXPORT_SYMBOL(cfpkt_info);
|
|
|
|
void cfpkt_set_prio(struct cfpkt *pkt, int prio)
|
|
{
|
|
pkt_to_skb(pkt)->priority = prio;
|
|
}
|
|
EXPORT_SYMBOL(cfpkt_set_prio);
|