sdpops: function to parse path for sdp content

src/modules/sdpops/sdpops_path.c

@@ -0,0 +1,133 @@
+/*
+ * Copyright (C) 2024 Daniel-Constantin Mierla (asipto.com)
+ *
+ * This file is part of Kamailio, a free SIP server.
+ *
+ * Kamailio is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version
+ *
+ * Kamailio is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ */
+
+
+#include <string.h>
+#include <stdlib.h>
+#include <stdio.h>
+
+#include "../../core/dprint.h"
+
+#include "sdpops_path.h"
+
+/**
+ *
+ */
+int sdpops_path_parse(str *vpath, sdp_path_t *rpath)
+{
+	int n;
+	int i;
+	if(vpath == NULL || vpath->s == NULL || vpath->len <= 0 || rpath == NULL) {
+		LM_ERR("invalid parameters\n");
+		return -1;
+	}
+	if(vpath->s[0] != '/') {
+		LM_ERR("sdp path must start with '/'\n");
+		return -1;
+	}
+	if(vpath->len <= 1 || vpath->len >= SDPOPS_SDPPATH_SIZE) {
+		LM_ERR("sdp path is too short or long [%.*s] (%d)\n", vpath->len,
+				vpath->s, vpath->len);
+		return -1;
+	}
+	memset(rpath, 0, sizeof(sdp_path_t));
+	memcpy(rpath->spbuf, vpath->s, vpath->len);
+	rpath->spbuf[vpath->len] = '\0';
+	rpath->spath.s = rpath->spbuf;
+	rpath->spath.len = vpath->len;
+
+	n = 0;
+	i = 1;
+	while(i < rpath->spath.len) {
+		rpath->ilist[n].name.s = rpath->spath.s + 1;
+		while((i < rpath->spath.len) && (rpath->spath.s[i] != '[')
+				&& (rpath->spath.s[i] != '/')) {
+			i++;
+		}
+		rpath->ilist[n].name.len = rpath->spath.s + i - rpath->ilist[n].name.s;
+		if(rpath->ilist[n].name.len <= 0) {
+			LM_ERR("invalid field in sdp path [%.*s] (n: %d)\n", vpath->len,
+					vpath->s, n);
+			return -1;
+		}
+		if(rpath->ilist[n].name.s[0] == '@') {
+			rpath->ilist[n].itype = SDPOPS_SDPTYPE_FATTR;
+		}
+		if(i == rpath->spath.len) {
+			goto done;
+		}
+		if(rpath->spath.s[i] == '[') {
+			/* index */
+			if(i > rpath->spath.len - 2) {
+				LM_ERR("invalid sdp path [%.*s] (n: %d)\n", vpath->len,
+						vpath->s, n);
+				return -1;
+			}
+			i++;
+			while((i < rpath->spath.len) && (rpath->spath.s[i] != ']')) {
+				if(rpath->spath.s[i] >= '0' && rpath->spath.s[i] <= '9') {
+					rpath->ilist[n].index = rpath->ilist[n].index * 10
+											+ (rpath->spath.s[i] - '0');
+				} else {
+					LM_ERR("invalid index insdp path [%.*s] (n: %d)\n",
+							vpath->len, vpath->s, n);
+					return -1;
+				}
+				i++;
+			}
+
+		} else {
+			/* path item */
+			if(n < SDPOPS_SDPPATH_DEPTH - 1) {
+				n++;
+			} else {
+				LM_ERR("overflowing sdp path depth: %d\n", n);
+				return -1;
+			}
+		}
+		i++;
+	}
+
+done:
+	if(rpath->ilist[n].name.s != NULL) {
+		rpath->icount = n + 1;
+	} else {
+		rpath->icount = n;
+	}
+	return 0;
+}
+
+/**
+ *
+ */
+int sdpops_path_debug(sdp_path_t *rpath)
+{
+	int i;
+	if(rpath == NULL) {
+		return -1;
+	}
+	for(i = 0; i < rpath->icount; i++) {
+		LM_DBG("item[%d]: name='%.*s' index=%d type=%d\n", i,
+				rpath->ilist[i].name.len, rpath->ilist[i].name.s,
+				rpath->ilist[i].index, rpath->ilist[i].itype);
+	}
+	return 0;
+}

src/modules/sdpops/sdpops_path.h

@@ -0,0 +1,53 @@
+/*
+ * Copyright (C) 2024 Daniel-Constantin Mierla (asipto.com)
+ *
+ * This file is part of Kamailio, a free SIP server.
+ *
+ * Kamailio is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version
+ *
+ * Kamailio is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ */
+
+
+#ifndef _SDPOPS_DATA_H_
+#define _SDPOPS_DATA_H_
+
+#include "../../core/str.h"
+#include "../../core/parser/sdp/sdp.h"
+
+#define SDPOPS_SDPPATH_SIZE 256
+#define SDPOPS_SDPPATH_DEPTH 4
+
+#define SDPOPS_SDPTYPE_FIELD 0
+#define SDPOPS_SDPTYPE_FATTR 1
+
+/* clang-format off */
+typedef struct sdp_path_item {
+	str name;
+	int index;
+	int itype;
+} sdp_path_item_t;
+
+typedef struct sdp_path {
+	char spbuf[SDPOPS_SDPPATH_SIZE];
+	str spath;
+	int icount;
+	sdp_path_item_t ilist[SDPOPS_SDPPATH_DEPTH];
+} sdp_path_t;
+/* clang-format on */
+
+int sdpops_path_parse(str *vpath, sdp_path_t *rpath);
+int sdpops_path_debug(sdp_path_t *rpath);
+
+#endif