Hi list,
after a code review session between Holger and me, I've now merged the
gtphub branch to master, completely. You can't miss the endless sequence
of commits that have just come in on master.
This is not to say that the code is glorified beyond doubt.
Please do review, if you can spare the time.
Thanks,
~Neels
--
- Neels Hofmeyr <nhofmeyr(a)sysmocom.de> http://www.sysmocom.de/
=======================================================================
* sysmocom - systems for mobile communications GmbH
* Alt-Moabit 93
* 10559 Berlin, Germany
* Sitz / Registered office: Berlin, HRB 134158 B
* Geschäftsführer / Managing Directors: Holger Freyther, Harald Welte
These functions originate from openbsc/src/gprs but are generic
msgb helper functions.
msgb_copy: This function allocates a new msgb, copies the data
buffer of msg, and adjusts the pointers (incl. l1h-l4h)
accordingly.
msgb_resize_area:
This resizes a sub area of the msgb data and adjusts the
pointers (incl. l1h-l4h) accordingly.
Sponsored-by: On-Waves ehf
---
include/osmocom/core/msgb.h | 3 ++
src/msgb.c | 88 +++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 91 insertions(+)
diff --git a/include/osmocom/core/msgb.h b/include/osmocom/core/msgb.h
index 644a639..21e363a 100644
--- a/include/osmocom/core/msgb.h
+++ b/include/osmocom/core/msgb.h
@@ -74,6 +74,9 @@ extern struct msgb *msgb_dequeue(struct llist_head *queue);
extern void msgb_reset(struct msgb *m);
uint16_t msgb_length(const struct msgb *msg);
extern const char *msgb_hexdump(const struct msgb *msg);
+extern int msgb_resize_area(struct msgb *msg, uint8_t *area,
+ size_t old_size, size_t new_size);
+extern struct msgb *msgb_copy(const struct msgb *msg, const char *name);
#ifdef MSGB_DEBUG
#include <osmocom/core/panic.h>
diff --git a/src/msgb.c b/src/msgb.c
index b2fe1d2..a257479 100644
--- a/src/msgb.c
+++ b/src/msgb.c
@@ -153,6 +153,94 @@ void msgb_set_talloc_ctx(void *ctx)
tall_msgb_ctx = ctx;
}
+/*! \brief Copy an msgb.
+ *
+ * This function allocates a new msgb, copies the data buffer of msg,
+ * and adjusts the pointers (incl l1h-l4h) accordingly. The cb part
+ * is not copied.
+ * \param[in] msg The old msgb object
+ * \param[in] name Human-readable name to be associated with msgb
+ */
+struct msgb *msgb_copy(const struct msgb *msg, const char *name)
+{
+ struct msgb *new_msg;
+
+ new_msg = msgb_alloc(msg->data_len, name);
+ if (!new_msg)
+ return NULL;
+
+ /* copy data */
+ memcpy(new_msg->_data, msg->_data, new_msg->data_len);
+
+ /* copy header */
+ new_msg->len = msg->len;
+ new_msg->data += msg->data - msg->_data;
+ new_msg->head += msg->head - msg->_data;
+ new_msg->tail += msg->tail - msg->_data;
+
+ if (msg->l1h)
+ new_msg->l1h = new_msg->_data + (msg->l1h - msg->_data);
+ if (msg->l2h)
+ new_msg->l2h = new_msg->_data + (msg->l2h - msg->_data);
+ if (msg->l3h)
+ new_msg->l3h = new_msg->_data + (msg->l3h - msg->_data);
+ if (msg->l4h)
+ new_msg->l4h = new_msg->_data + (msg->l4h - msg->_data);
+
+ return new_msg;
+}
+
+/*! \brief Resize an area within an msgb
+ *
+ * This resizes a sub area of the msgb data and adjusts the pointers (incl
+ * l1h-l4h) accordingly. The cb part is not updated. If the area is extended,
+ * the contents of the extension is undefined. The complete sub area must be a
+ * part of [data,tail].
+ *
+ * \param[inout] msg The msgb object
+ * \param[in] area A pointer to the sub-area
+ * \param[in] old_size The old size of the sub-area
+ * \param[in] new_size The new size of the sub-area
+ * \returns 0 on success, -1 if there is not enough space to extend the area
+ */
+int msgb_resize_area(struct msgb *msg, uint8_t *area,
+ size_t old_size, size_t new_size)
+{
+ int rc;
+ uint8_t *rest = area + old_size;
+ int rest_len = msg->len - old_size - (area - msg->data);
+ int delta_size = (int)new_size - (int)old_size;
+
+ if (area < msg->data || rest > msg->tail)
+ MSGB_ABORT(msg, "Sub area is not fully contained in the msg data\n");
+
+ if (delta_size == 0)
+ return 0;
+
+ if (delta_size > 0) {
+ rc = msgb_trim(msg, msg->len + delta_size);
+ if (rc < 0)
+ return rc;
+ }
+
+ memmove(area + new_size, area + old_size, rest_len);
+
+ if (msg->l1h >= rest)
+ msg->l1h += delta_size;
+ if (msg->l2h >= rest)
+ msg->l2h += delta_size;
+ if (msg->l3h >= rest)
+ msg->l3h += delta_size;
+ if (msg->l4h >= rest)
+ msg->l4h += delta_size;
+
+ if (delta_size < 0)
+ msgb_trim(msg, msg->len + delta_size);
+
+ return 0;
+}
+
+
/*! \brief Return a (static) buffer containing a hexdump of the msg
* \param[in] msg message buffer
* \returns a pointer to a static char array
--
1.9.1
