Add _c versions of functions that otherwise return static buffers

We have a habit of returning static buffers from some functions,
particularly when generating some kind of string values.  This is
convenient in terms of memory management, but it comes at the expense
of not being thread-safe, and not allowing for two calls of the
related function within one printf() statement.

Let's introduce _c suffix versions of those functions where the
caller passes in a talloc context from which the output buffer shall
be allocated.

Change-Id: I8481c19b68ff67cfa22abb93c405ebcfcb0ab19b

1 files changed, 26 insertions, 0 deletions

diff --git a/include/osmocom/core/msgb.h b/include/osmocom/core/msgb.h
index 0c51ce26..e05d37f0 100644
--- a/include/osmocom/core/msgb.h
+++ b/include/osmocom/core/msgb.h
@@ -60,6 +60,7 @@ struct msgb {
 	unsigned char _data[0]; /*!< optional immediate data array */
 };
 
+extern struct msgb *msgb_alloc_c(const void *ctx, uint16_t size, const char *name);
 extern struct msgb *msgb_alloc(uint16_t size, const char *name);
 extern void msgb_free(struct msgb *m);
 extern void msgb_enqueue(struct llist_head *queue, struct msgb *msg);
@@ -68,9 +69,11 @@ extern void msgb_reset(struct msgb *m);
 uint16_t msgb_length(const struct msgb *msg);
 extern const char *msgb_hexdump(const struct msgb *msg);
 char *msgb_hexdump_buf(char *buf, size_t buf_len, const struct msgb *msg);
+char *msgb_hexdump_c(const void *ctx, const struct msgb *msg);
 extern int msgb_resize_area(struct msgb *msg, uint8_t *area,
 	int old_size, int new_size);
 extern struct msgb *msgb_copy(const struct msgb *msg, const char *name);
+extern struct msgb *msgb_copy_c(const void *ctx, const struct msgb *msg, const char *name);
 static int msgb_test_invariant(const struct msgb *msg) __attribute__((pure));
 
 /*! Free all msgbs from a queue built with msgb_enqueue().
@@ -501,6 +504,29 @@ static inline int msgb_l3trim(struct msgb *msg, int l3len)
 	return msgb_trim(msg, (msg->l3h - msg->data) + l3len);
 }
 
+/*! Allocate message buffer with specified headroom from specified talloc context.
+ *  \param[in] ctx talloc context from which to allocate
+ *  \param[in] size size in bytes, including headroom
+ *  \param[in] headroom headroom in bytes
+ *  \param[in] name human-readable name
+ *  \returns allocated message buffer with specified headroom
+ *
+ * This function is a convenience wrapper around \ref msgb_alloc
+ * followed by \ref msgb_reserve in order to create a new \ref msgb with
+ * user-specified amount of headroom.
+ */
+static inline struct msgb *msgb_alloc_headroom_c(const void *ctx, int size, int headroom,
+						 const char *name)
+{
+	osmo_static_assert(size > headroom, headroom_bigger);
+
+	struct msgb *msg = msgb_alloc_c(ctx, size, name);
+	if (msg)
+		msgb_reserve(msg, headroom);
+	return msg;
+}
+
+
 /*! Allocate message buffer with specified headroom
  *  \param[in] size size in bytes, including headroom
  *  \param[in] headroom headroom in bytes