1 files changed, 186 insertions, 0 deletions
diff --git a/src/sdp.c b/src/sdp.c
new file mode 100644
index 0000000..7a8ed29
--- /dev/null
+++ b/src/sdp.c
@@ -0,0 +1,186 @@
+/**
+ * @file src/sdp.c  SDP functions
+ *
+ * Copyright (C) 2011 Creytiv.com
+ */
+#include <stdlib.h>
+#include <re.h>
+#include <baresip.h>
+#include "core.h"
+
+
+uint32_t sdp_media_rattr_u32(const struct sdp_media *m, const char *name)
+{
+	const char *attr = sdp_media_rattr(m, name);
+	return attr ? atoi(attr) : 0;
+}
+
+
+/*
+ * Get a remote attribute from the SDP. Try the media-level first,
+ * and if it does not exist then try session-level.
+ */
+const char *sdp_rattr(const struct sdp_session *s, const struct sdp_media *m,
+		      const char *name)
+{
+	const char *x;
+
+	x = sdp_media_rattr(m, name);
+	if (x)
+		return x;
+
+	x = sdp_session_rattr(s, name);
+	if (x)
+		return x;
+
+	return NULL;
+}
+
+
+/* RFC 4572 */
+int sdp_fingerprint_decode(const char *attr, struct pl *hash,
+			   uint8_t *md, size_t *sz)
+{
+	struct pl f;
+	const char *p;
+	int err;
+
+	if (!attr || !hash)
+		return EINVAL;
+
+	err = re_regex(attr, str_len(attr), "[^ ]+ [0-9A-F:]+", hash, &f);
+	if (err)
+		return err;
+
+	if (md && sz) {
+		if (*sz < (f.l+1)/3)
+			return EOVERFLOW;
+
+		for (p = f.p; p < (f.p+f.l); p += 3) {
+			*md++ = ch_hex(p[0]) << 4 | ch_hex(p[1]);
+		}
+
+		*sz = (f.l+1)/3;
+	}
+
+	return 0;
+}
+
+
+bool sdp_media_has_media(const struct sdp_media *m)
+{
+	bool has;
+
+	has = sdp_media_rformat(m, NULL) != NULL;
+	if (has)
+		return sdp_media_rport(m) != 0;
+
+	return false;
+}
+
+
+/**
+ * Find a dynamic payload type that is not used
+ *
+ * @param m SDP Media
+ *
+ * @return Unused payload type, -1 if no found
+ */
+int sdp_media_find_unused_pt(const struct sdp_media *m)
+{
+	int pt;
+
+	for (pt = PT_DYN_MAX; pt>=PT_DYN_MIN; pt--) {
+
+		if (!sdp_media_format(m, false, NULL, pt, NULL, -1, -1))
+			return pt;
+	}
+
+	return -1;
+}
+
+
+const struct sdp_format *sdp_media_format_cycle(struct sdp_media *m)
+{
+	struct sdp_format *sf;
+	struct list *lst;
+
+ again:
+	sf = (struct sdp_format *)sdp_media_rformat(m, NULL);
+	if (!sf)
+		return NULL;
+
+	lst = sf->le.list;
+
+	/* move top-most codec to end of list */
+	list_unlink(&sf->le);
+	list_append(lst, &sf->le, sf);
+
+	sf = (struct sdp_format *)sdp_media_rformat(m, NULL);
+	if (!str_casecmp(sf->name, telev_rtpfmt))
+		goto again;
+
+	return sf;
+}
+
+
+static void decode_part(const struct pl *part, struct mbuf *mb)
+{
+	struct pl hdrs, body;
+
+	if (re_regex(part->p, part->l, "\r\n\r\n[^]+", &body))
+		return;
+
+	hdrs.p = part->p;
+	hdrs.l = body.p - part->p - 2;
+
+	if (0 == re_regex(hdrs.p, hdrs.l, "application/sdp")) {
+
+		mb->pos += (body.p - (char *)mbuf_buf(mb));
+		mb->end  = mb->pos + body.l;
+	}
+}
+
+
+/**
+ * Decode a multipart/mixed message and find the part with application/sdp
+ */
+int sdp_decode_multipart(const struct pl *ctype, struct mbuf *mb)
+{
+	struct pl bnd, s, e, p;
+	char expr[64];
+	int err;
+
+	if (!ctype || !mb)
+		return EINVAL;
+
+	/* fetch the boundary tag, excluding quotes */
+	err = re_regex(ctype->p, ctype->l,
+		       "multipart/mixed;[ \t]*boundary=[~]+", NULL, &bnd);
+	if (err)
+		return err;
+
+	if (re_snprintf(expr, sizeof(expr), "--%r[^]+", &bnd) < 0)
+		return ENOMEM;
+
+	/* find 1st boundary */
+	err = re_regex((char *)mbuf_buf(mb), mbuf_get_left(mb), expr, &s);
+	if (err)
+		return err;
+
+	/* iterate over each part */
+	while (s.l > 2) {
+		if (re_regex(s.p, s.l, expr, &e))
+			return 0;
+
+		p.p = s.p + 2;
+		p.l = e.p - p.p - bnd.l - 2;
+
+		/* valid part in "p" */
+		decode_part(&p, mb);
+
+		s = e;
+	}
+
+	return 0;
+}