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authorHarald Welte <laforge@gnumonks.org>2012-09-08 19:58:59 +0200
committerHarald Welte <laforge@gnumonks.org>2012-09-08 20:01:00 +0200
commit972b502ecaf3b919b7e89c13257dd6ec97aaafb7 (patch)
tree654858a93bcc997a644352d649d8f67a02bd9222
parentb1789b044a202e0fc33651f82efbe630d58fa416 (diff)
msgb: msgb_get() is supposed to get bytes from END, msgb_pull() from HEAD
msgb_get() has been wrong all the time, despite the documentation being correct. If you've used the broken msgb_get() before, you have to change your code now, sorry.
-rw-r--r--include/osmocom/core/msgb.h37
1 files changed, 34 insertions, 3 deletions
diff --git a/include/osmocom/core/msgb.h b/include/osmocom/core/msgb.h
index 5457a07d..36c7c0f9 100644
--- a/include/osmocom/core/msgb.h
+++ b/include/osmocom/core/msgb.h
@@ -72,6 +72,7 @@ extern void msgb_free(struct msgb *m);
extern void msgb_enqueue(struct llist_head *queue, struct msgb *msg);
extern struct msgb *msgb_dequeue(struct llist_head *queue);
extern void msgb_reset(struct msgb *m);
+uint16_t msgb_length(const struct msgb *msg);
#ifdef MSGB_DEBUG
#include <osmocom/core/panic.h>
@@ -226,8 +227,11 @@ static inline void msgb_put_u32(struct msgb *msgb, uint32_t word)
*/
static inline unsigned char *msgb_get(struct msgb *msgb, unsigned int len)
{
- unsigned char *tmp = msgb->data;
- msgb->data += len;
+ unsigned char *tmp = msgb->data - len;
+ if (msgb_length(msgb) < len)
+ MSGB_ABORT(msgb, "msgb too small to get %u (len %u)\n",
+ len, msgb_length(msgb));
+ msgb->tail -= len;
msgb->len -= len;
return tmp;
}
@@ -295,6 +299,34 @@ static inline unsigned char *msgb_pull(struct msgb *msgb, unsigned int len)
return msgb->data += len;
}
+/*! \brief remove uint8 from front of message
+ * \param[in] msgb message buffer
+ * \returns 8bit value taken from end of msgb
+ */
+static inline uint8_t msgb_pull_u8(struct msgb *msgb)
+{
+ uint8_t *space = msgb_pull(msgb, 1);
+ return space[0];
+}
+/*! \brief remove uint16 from front of message
+ * \param[in] msgb message buffer
+ * \returns 16bit value taken from end of msgb
+ */
+static inline uint16_t msgb_pull_u16(struct msgb *msgb)
+{
+ uint8_t *space = msgb_pull(msgb, 2);
+ return space[0] << 8 | space[1];
+}
+/*! \brief remove uint32 from front of message
+ * \param[in] msgb message buffer
+ * \returns 32bit value taken from end of msgb
+ */
+static inline uint32_t msgb_pull_u32(struct msgb *msgb)
+{
+ uint8_t *space = msgb_pull(msgb, 4);
+ return space[0] << 24 | space[1] << 16 | space[2] << 8 | space[3];
+}
+
/*! \brief Increase headroom of empty msgb, reducing the tailroom
* \param[in] msg message buffer
* \param[in] len amount of extra octets to be reserved as headroom
@@ -362,7 +394,6 @@ static inline struct msgb *msgb_alloc_headroom(int size, int headroom,
/* non inline functions to ease binding */
uint8_t *msgb_data(const struct msgb *msg);
-uint16_t msgb_length(const struct msgb *msg);
void msgb_set_talloc_ctx(void *ctx);
/*! @} */