Clean up and ensure proper usage of alloca()

This replaces all calls to alloca() with ast_alloca() which calls gcc's
__builtin_alloca() to avoid BSD semantics and removes all NULL checks
on memory allocated via ast_alloca() and ast_strdupa().

(closes issue ASTERISK-20125)
Review: https://reviewboard.asterisk.org/r/2032/
Patch-by: Walter Doekes (wdoekes)
........

Merged revisions 370642 from http://svn.asterisk.org/svn/asterisk/branches/1.8
........

Merged revisions 370643 from http://svn.asterisk.org/svn/asterisk/branches/10


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@370655 65c4cc65-6c06-0410-ace0-fbb531ad65f3

5 files changed, 10 insertions, 9 deletions

diff --git a/res/ael/pval.c b/res/ael/pval.c
index ff425f543..70bd68986 100644
--- a/res/ael/pval.c
+++ b/res/ael/pval.c
@@ -2902,7 +2902,7 @@ void ael2_semantic_check(pval *item, int *arg_errs, int *arg_warns, int *arg_not
 	if (!item)
 		return; /* don't check an empty tree */
 #ifdef AAL_ARGCHECK
-	rfilename = alloca(10 + strlen(ast_config_AST_VAR_DIR));
+	rfilename = ast_alloca(10 + strlen(ast_config_AST_VAR_DIR));
 	sprintf(rfilename, "%s/applist", ast_config_AST_VAR_DIR);
 	
 	apps = argdesc_parse(rfilename, &argapp_errs); /* giveth */
diff --git a/res/res_agi.c b/res/res_agi.c
index 328674c5a..6f7675f53 100644
--- a/res/res_agi.c
+++ b/res/res_agi.c
@@ -1571,10 +1571,11 @@ static enum agi_result launch_ha_netscript(char *agiurl, char *argv[], int *fds)
 	unsigned short srvport;
 
 	/* format of agiurl is "hagi://host.domain[:port][/script/name]" */
-	if (!(host = ast_strdupa(agiurl + 7))) { /* Remove hagi:// */
+	if (strlen(agiurl) < 7) { /* Remove hagi:// */
 		ast_log(LOG_WARNING, "An error occurred parsing the AGI URI: %s", agiurl);
 		return AGI_RESULT_FAILURE;
 	}
+	host = ast_strdupa(agiurl + 7);
 
 	/* Strip off any script name */
 	if ((script = strchr(host, '/'))) {
@@ -2500,7 +2501,7 @@ static int handle_exec(struct ast_channel *chan, AGI *agi, int argc, const char
 			ast_set_flag(ast_channel_flags(chan), AST_FLAG_DISABLE_WORKAROUNDS);
 		}
 		if (ast_compat_res_agi && argc >= 3 && !ast_strlen_zero(argv[2])) {
-			char *compat = alloca(strlen(argv[2]) * 2 + 1), *cptr;
+			char *compat = ast_alloca(strlen(argv[2]) * 2 + 1), *cptr;
 			const char *vptr;
 			for (cptr = compat, vptr = argv[2]; *vptr; vptr++) {
 				if (*vptr == ',') {
diff --git a/res/res_config_pgsql.c b/res/res_config_pgsql.c
index 02c76fcfe..bafa27197 100644
--- a/res/res_config_pgsql.c
+++ b/res/res_config_pgsql.c
@@ -290,7 +290,7 @@ static struct tables *find_table(const char *database, const char *orig_tablenam
 		if (strchr(schemaname, '\\') || strchr(schemaname, '\'')) {
 			char *tmp = schemaname, *ptr;
 
-			ptr = schemaname = alloca(strlen(tmp) * 2 + 1);
+			ptr = schemaname = ast_alloca(strlen(tmp) * 2 + 1);
 			for (; *tmp; tmp++) {
 				if (strchr("\\'", *tmp)) {
 					*ptr++ = *tmp;
@@ -303,7 +303,7 @@ static struct tables *find_table(const char *database, const char *orig_tablenam
 		if (strchr(tablename, '\\') || strchr(tablename, '\'')) {
 			char *tmp = tablename, *ptr;
 
-			ptr = tablename = alloca(strlen(tmp) * 2 + 1);
+			ptr = tablename = ast_alloca(strlen(tmp) * 2 + 1);
 			for (; *tmp; tmp++) {
 				if (strchr("\\'", *tmp)) {
 					*ptr++ = *tmp;
@@ -322,7 +322,7 @@ static struct tables *find_table(const char *database, const char *orig_tablenam
 			const char *tmp = orig_tablename;
 			char *ptr;
 
-			orig_tablename = ptr = alloca(strlen(tmp) * 2 + 1);
+			orig_tablename = ptr = ast_alloca(strlen(tmp) * 2 + 1);
 			for (; *tmp; tmp++) {
 				if (strchr("\\'", *tmp)) {
 					*ptr++ = *tmp;
diff --git a/res/res_http_websocket.c b/res/res_http_websocket.c
index c5fcdeeee..86e2a82a3 100644
--- a/res/res_http_websocket.c
+++ b/res/res_http_websocket.c
@@ -208,7 +208,7 @@ int ast_websocket_write(struct ast_websocket *session, enum ast_websocket_opcode
 		header_size += 8;
 	}
 
-	frame = alloca(header_size);
+	frame = ast_alloca(header_size);
 	memset(frame, 0, sizeof(*frame));
 
 	frame[0] = opcode | 0x80;
diff --git a/res/res_jabber.c b/res/res_jabber.c
index c160266b0..9cab2f159 100644
--- a/res/res_jabber.c
+++ b/res/res_jabber.c
@@ -1585,8 +1585,8 @@ static int aji_start_sasl(struct aji_client *client, enum ikssasltype type, char
 
 	iks_insert_attrib(x, "xmlns", IKS_NS_XMPP_SASL);
 	len = strlen(username) + strlen(pass) + 3;
-	s = alloca(len);
-	base64 = alloca((len + 2) * 4 / 3);
+	s = ast_alloca(len);
+	base64 = ast_alloca((len + 2) * 4 / 3);
 	iks_insert_attrib(x, "mechanism", "PLAIN");
 	snprintf(s, len, "%c%s%c%s", 0, username, 0, pass);