net-caif: add CAIF generic caif support functions
Support functions for the caif protocol stack:
cfcnfg.c - CAIF Configuration Module used for
adding and removing drivers and connection
cfpkt_skbuff.c - CAIF Packet layer (SKB helper functions)
Signed-off-by: Sjur Braendeland <sjur.brandeland@stericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/caif/cfpkt_skbuff.c b/net/caif/cfpkt_skbuff.c
new file mode 100644
index 0000000..83fff2f
--- /dev/null
+++ b/net/caif/cfpkt_skbuff.c
@@ -0,0 +1,571 @@
+/*
+ * 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);