diff options
Diffstat (limited to 'net/caif/cfpkt_skbuff.c')
| -rw-r--r-- | net/caif/cfpkt_skbuff.c | 580 |
1 files changed, 580 insertions, 0 deletions
diff --git a/net/caif/cfpkt_skbuff.c b/net/caif/cfpkt_skbuff.c new file mode 100644 index 000000000000..a6fdf899741a --- /dev/null +++ b/net/caif/cfpkt_skbuff.c @@ -0,0 +1,580 @@ +/* + * 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; + int ret; + 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 */ + ret = skb_cow_data(skb, 0, &lastskb); + if (unlikely(ret < 0)) { + PKT_ERROR(pkt, "cfpkt_add_head: 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); +} +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 (!pkt) + return NULL; + 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 */ + 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_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); + 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, + "cfpkt_split: trying to split beyond end of packet"); + 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; + + /* 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); |