sdpops: new module for SDP operations

- the module is intended to export functions that will allow easier
  management of SDP from configuration file
- first function: spd_remove_codecs_by_id(list)
	- remove the codecs by their numeric IDs given in a comma separated list as paramter
	- codecs attributes are not removed yet

modules/sdpops/Makefile

@@ -0,0 +1,14 @@
+# $Id$
+#
+# 
+# WARNING: do not run this directly, it should be run by the master Makefile
+
+include ../../Makefile.defs
+auto_gen=
+NAME=sdpops.so
+DEFS +=
+LIBS +=
+
+DEFS+=-DOPENSER_MOD_INTERFACE
+
+include ../../Makefile.modules

modules/sdpops/sdpops_mod.c

@@ -0,0 +1,257 @@
+/*
+ * $Id$
+ *
+ * Copyright (C) 2011 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ */
+
+
+#include <string.h>
+#include <stdlib.h>
+#include <stdio.h>
+
+#include "../../sr_module.h"
+#include "../../dprint.h"
+#include "../../mod_fix.h"
+#include "../../pvar.h"
+#include "../../trim.h"
+#include "../../parser/sdp/sdp.h"
+#include "../../data_lump.h"
+
+
+MODULE_VERSION
+
+static int w_sdp_remove_codecs_by_id(sip_msg_t* msg, char* codecs, char *bar);
+static int fixup_sdp_remove_codecs_by_id(void** param, int param_no);
+
+static int mod_init(void);
+
+static cmd_export_t cmds[] = {
+	{"sdp_remove_codecs_by_id",    (cmd_function)w_sdp_remove_codecs_by_id,
+		1, fixup_sdp_remove_codecs_by_id,  0, ANY_ROUTE},
+	{0, 0, 0, 0, 0}
+};
+
+static pv_export_t mod_pvs[] = {
+#if 0
+	{{"sdp", (sizeof("sdp")-1)}, /* */
+		PVT_OTHER, pv_get_sdp, 0,
+		0, 0, 0, 0},
+#endif
+
+	{ {0, 0}, 0, 0, 0, 0, 0, 0, 0 }
+};
+
+static param_export_t params[] = {
+	{0, 0, 0}
+};
+
+/** module exports */
+struct module_exports exports= {
+	"sdpops",
+	DEFAULT_DLFLAGS, /* dlopen flags */
+	cmds,
+	params,
+	0,          /* exported statistics */
+	0  ,        /* exported MI functions */
+	mod_pvs,    /* exported pseudo-variables */
+	0,          /* extra processes */
+	mod_init,   /* module initialization function */
+	0,
+	0,
+	0           /* per-child init function */
+};
+
+/** 
+ * 
+ */
+static int mod_init(void)
+{
+	LM_DBG("sdpops module loaded\n");
+	return 0;
+}
+
+
+/**
+ *
+ */
+int str_find_token(str *text, str *result, char delim)
+{
+	int i;
+	if(text==NULL || result==NULL)
+		return -1;
+	if(text->s[0] == delim)
+	{
+		 text->s += 1;
+		 text->len -= 1;
+	}
+	trim_leading(text);
+	result->s = text->s;
+	result->len = 0;
+	for (i=0; i<text->len; i++)
+	{
+		if(result->s[i]==delim || result->s[i]=='\0'
+				|| result->s[i]=='\r' || result->s[i]=='\n')
+			return 0;
+		result->len++;
+	}
+	return 0;
+}
+
+
+int sdp_remove_str_codec_id(sip_msg_t* msg, str *allcodecs, str* rmcodec)
+{
+	int i;
+	int cmp;
+	struct lump *anchor;
+
+	if(msg==NULL || allcodecs==NULL || rmcodec==NULL
+			|| allcodecs->len<=0 || rmcodec->len<=0)
+		return -1;
+
+	cmp = 1;
+	for(i=0; i<allcodecs->len; i++) {
+		if(cmp==1) {
+			if(rmcodec->len <= allcodecs->len-i) {
+				if(strncmp(&allcodecs->s[i], rmcodec->s, rmcodec->len)==0) {
+					if(&allcodecs->s[i+rmcodec->len]
+									== &allcodecs->s[allcodecs->len]
+							|| allcodecs->s[i+rmcodec->len] == ' ') {
+						/* match - remove also the space before codec id */
+						LM_DBG("found codec [%.*s] inside [%.*s]\n",
+									rmcodec->len, rmcodec->s,
+									allcodecs->len, allcodecs->s);
+						anchor = del_lump(msg, &allcodecs->s[i-1] - msg->buf,
+								rmcodec->len+1, 0);
+						if (anchor == NULL) {
+							LM_ERR("failed to remove [%.*s] inside [%.*s]\n",
+									rmcodec->len, rmcodec->s,
+									allcodecs->len, allcodecs->s);
+							return -1;
+						}
+						return 0;
+					}
+				}
+			}
+		}
+		if(allcodecs->s[i]==' ')
+			cmp = 1;
+		else
+			cmp = 0;
+	}
+
+	return 0;
+}
+
+/**
+ *
+ */
+int sdp_remove_codecs_by_id(sip_msg_t* msg, str* codecs)
+{
+	sdp_info_t *sdp = NULL;
+	int sdp_session_num;
+	int sdp_stream_num;
+	sdp_session_cell_t* sdp_session;
+	sdp_stream_cell_t* sdp_stream;
+	str sdp_codecs;
+	str tmp_codecs;
+	str rm_codec;
+
+	if(parse_sdp(msg) < 0) {
+		LM_ERR("Unable to parse sdp\n");
+		return -1;
+	}
+
+	LM_ERR("attempting to remove codecs from sdp: [%.*s]\n",
+			codecs->len, codecs->s);
+
+	sdp = (sdp_info_t*)msg->body;
+
+	print_sdp(sdp, L_DBG);
+
+	sdp_session_num = 0;
+	for(;;)
+	{
+		sdp_session = get_sdp_session(msg, sdp_session_num);
+		if(!sdp_session) break;
+		sdp_stream_num = 0;
+		for(;;)
+		{
+			sdp_stream = get_sdp_stream(msg, sdp_session_num, sdp_stream_num);
+			if(!sdp_stream) break;
+
+			LM_DBG("stream %d of %d - payloads [%.*s]\n",
+				sdp_stream_num, sdp_session_num, 
+				sdp_stream->payloads.len, sdp_stream->payloads.s);
+			sdp_codecs = sdp_stream->payloads;
+			tmp_codecs = *codecs;
+			while(str_find_token(&tmp_codecs, &rm_codec, ',')==0
+					&& rm_codec.len>0)
+			{
+				tmp_codecs.len -=(int)(&rm_codec.s[rm_codec.len]-tmp_codecs.s);
+				tmp_codecs.s = rm_codec.s + rm_codec.len;
+
+				LM_DBG("codecs [%.*s] - remove [%.*s]\n",
+						sdp_codecs.len, sdp_codecs.s,
+						rm_codec.len, rm_codec.s);
+				sdp_remove_str_codec_id(msg, &sdp_codecs, &rm_codec);
+			}
+			sdp_stream_num++;
+		}
+		sdp_session_num++;
+	}
+
+	return 0;
+}
+
+/**
+ *
+ */
+static int w_sdp_remove_codecs_by_id(sip_msg_t* msg, char* codecs, char* bar)
+{
+	str lcodecs = {0, 0};
+
+	if(codecs==0)
+	{
+		LM_ERR("invalid parameters\n");
+		return -1;
+	}
+
+	if(fixup_get_svalue(msg, (gparam_p)codecs, &lcodecs)!=0)
+	{
+		LM_ERR("unable to get the list of codecs\n");
+		return -1;
+	}
+
+	if(sdp_remove_codecs_by_id(msg, &lcodecs)<0)
+		return -1;
+	return 1;
+}
+
+
+/** 
+ * 
+ */
+static int fixup_sdp_remove_codecs_by_id(void** param, int param_no)
+{
+	if (param_no == 1) {
+	    return fixup_spve_null(param, 1);
+	}
+	return 0;
+}