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, 105 insertions, 116 deletions

diff --git a/pbx/pbx_ael.c b/pbx/pbx_ael.c
index 94a6212fa..5c42732bf 100644
--- a/pbx/pbx_ael.c
+++ b/pbx/pbx_ael.c
@@ -165,7 +165,7 @@ static int pbx_load_module(void)
 	if (config[0] == '/')
 		rfilename = (char *)config;
 	else {
-		rfilename = alloca(strlen(config) + strlen(ast_config_AST_CONFIG_DIR) + 2);
+		rfilename = ast_alloca(strlen(config) + strlen(ast_config_AST_CONFIG_DIR) + 2);
 		sprintf(rfilename, "%s/%s", ast_config_AST_CONFIG_DIR, config);
 	}
 	if (access(rfilename,R_OK) != 0) {
diff --git a/pbx/pbx_dundi.c b/pbx/pbx_dundi.c
index 52430838a..25871b1fb 100644
--- a/pbx/pbx_dundi.c
+++ b/pbx/pbx_dundi.c
@@ -1390,9 +1390,7 @@ static struct dundi_hdr *dundi_decrypt(struct dundi_transaction *trans, unsigned
 	unsigned long bytes;
 	struct dundi_hdr *h;
 	unsigned char *decrypt_space;
-	decrypt_space = alloca(srclen);
-	if (!decrypt_space)
-		return NULL;
+	decrypt_space = ast_alloca(srclen);
 	decrypt_memcpy(decrypt_space, src->encdata, srclen, src->iv, &trans->dcx);
 	/* Setup header */
 	h = (struct dundi_hdr *)dst;
@@ -1418,61 +1416,58 @@ static int dundi_encrypt(struct dundi_transaction *trans, struct dundi_packet *p
 	struct dundi_peer *peer;
 	unsigned char iv[16];
 	len = pack->datalen + pack->datalen / 100 + 42;
-	compress_space = alloca(len);
-	if (compress_space) {
-		memset(compress_space, 0, len);
-		/* We care about everthing save the first 6 bytes of header */
-		bytes = len;
-		res = compress(compress_space, &bytes, pack->data + 6, pack->datalen - 6);
-		if (res != Z_OK) {
-			ast_debug(1, "Ouch, compression failed!\n");
+	compress_space = ast_alloca(len);
+	memset(compress_space, 0, len);
+	/* We care about everthing save the first 6 bytes of header */
+	bytes = len;
+	res = compress(compress_space, &bytes, pack->data + 6, pack->datalen - 6);
+	if (res != Z_OK) {
+		ast_debug(1, "Ouch, compression failed!\n");
+		return -1;
+	}
+	memset(&ied, 0, sizeof(ied));
+	/* Say who we are */
+	if (!pack->h->iseqno && !pack->h->oseqno) {
+		/* Need the key in the first copy */
+		if (!(peer = find_peer(&trans->them_eid)))
 			return -1;
-		}
-		memset(&ied, 0, sizeof(ied));
-		/* Say who we are */
-		if (!pack->h->iseqno && !pack->h->oseqno) {
-			/* Need the key in the first copy */
-			if (!(peer = find_peer(&trans->them_eid)))
-				return -1;
-			if (update_key(peer))
-				return -1;
-			if (!peer->sentfullkey)
-				ast_set_flag(trans, FLAG_SENDFULLKEY);
-			/* Append key data */
-			dundi_ie_append_eid(&ied, DUNDI_IE_EID, &trans->us_eid);
-			if (ast_test_flag(trans, FLAG_SENDFULLKEY)) {
-				dundi_ie_append_raw(&ied, DUNDI_IE_SHAREDKEY, peer->txenckey, 128);
-				dundi_ie_append_raw(&ied, DUNDI_IE_SIGNATURE, peer->txenckey + 128, 128);
-			} else {
-				dundi_ie_append_int(&ied, DUNDI_IE_KEYCRC32, peer->us_keycrc32);
-			}
-			/* Setup contexts */
-			trans->ecx = peer->us_ecx;
-			trans->dcx = peer->us_dcx;
-
-			/* We've sent the full key */
-			peer->sentfullkey = 1;
-		}
-		/* Build initialization vector */
-		build_iv(iv);
-		/* Add the field, rounded up to 16 bytes */
-		dundi_ie_append_encdata(&ied, DUNDI_IE_ENCDATA, iv, NULL, ((bytes + 15) / 16) * 16);
-		/* Copy the data */
-		if ((ied.pos + bytes) >= sizeof(ied.buf)) {
-			ast_log(LOG_NOTICE, "Final packet too large!\n");
+		if (update_key(peer))
 			return -1;
+		if (!peer->sentfullkey)
+			ast_set_flag(trans, FLAG_SENDFULLKEY);
+		/* Append key data */
+		dundi_ie_append_eid(&ied, DUNDI_IE_EID, &trans->us_eid);
+		if (ast_test_flag(trans, FLAG_SENDFULLKEY)) {
+			dundi_ie_append_raw(&ied, DUNDI_IE_SHAREDKEY, peer->txenckey, 128);
+			dundi_ie_append_raw(&ied, DUNDI_IE_SIGNATURE, peer->txenckey + 128, 128);
+		} else {
+			dundi_ie_append_int(&ied, DUNDI_IE_KEYCRC32, peer->us_keycrc32);
 		}
-		encrypt_memcpy(ied.buf + ied.pos, compress_space, bytes, iv, &trans->ecx);
-		ied.pos += ((bytes + 15) / 16) * 16;
-		/* Reconstruct header */
-		pack->datalen = sizeof(struct dundi_hdr);
-		pack->h->cmdresp = DUNDI_COMMAND_ENCRYPT;
-		pack->h->cmdflags = 0;
-		memcpy(pack->h->ies, ied.buf, ied.pos);
-		pack->datalen += ied.pos;
-		return 0;
+		/* Setup contexts */
+		trans->ecx = peer->us_ecx;
+		trans->dcx = peer->us_dcx;
+
+		/* We've sent the full key */
+		peer->sentfullkey = 1;
+	}
+	/* Build initialization vector */
+	build_iv(iv);
+	/* Add the field, rounded up to 16 bytes */
+	dundi_ie_append_encdata(&ied, DUNDI_IE_ENCDATA, iv, NULL, ((bytes + 15) / 16) * 16);
+	/* Copy the data */
+	if ((ied.pos + bytes) >= sizeof(ied.buf)) {
+		ast_log(LOG_NOTICE, "Final packet too large!\n");
+		return -1;
 	}
-	return -1;
+	encrypt_memcpy(ied.buf + ied.pos, compress_space, bytes, iv, &trans->ecx);
+	ied.pos += ((bytes + 15) / 16) * 16;
+	/* Reconstruct header */
+	pack->datalen = sizeof(struct dundi_hdr);
+	pack->h->cmdresp = DUNDI_COMMAND_ENCRYPT;
+	pack->h->cmdflags = 0;
+	memcpy(pack->h->ies, ied.buf, ied.pos);
+	pack->datalen += ied.pos;
+	return 0;
 }
 
 static int check_key(struct dundi_peer *peer, unsigned char *newkey, unsigned char *newsig, uint32_t keycrc32)
@@ -1589,10 +1584,7 @@ static int handle_command_response(struct dundi_transaction *trans, struct dundi
 	}
 
 	if (datalen) {
-		bufcpy = alloca(datalen);
-		if (!bufcpy) {
-			goto return_cleanup;
-		}
+		bufcpy = ast_alloca(datalen);
 		/* Make a copy for parsing */
 		memcpy(bufcpy, hdr->ies, datalen);
 		ast_debug(1, "Got canonical message %d (%d), %d bytes data%s\n", cmd, hdr->oseqno, datalen, final ? " (Final)" : "");
@@ -3774,18 +3766,17 @@ static int dundi_precache_internal(const char *context, const char *number, int
 			nummaps++;
 	}
 	if (nummaps) {
-		maps = alloca(nummaps * sizeof(*maps));
+		maps = ast_alloca(nummaps * sizeof(*maps));
 		nummaps = 0;
-		if (maps) {
-			AST_LIST_TRAVERSE(&mappings, cur, list) {
-				if (!strcasecmp(cur->dcontext, context))
-					maps[nummaps++] = *cur;
-			}
+		AST_LIST_TRAVERSE(&mappings, cur, list) {
+			if (!strcasecmp(cur->dcontext, context))
+				maps[nummaps++] = *cur;
 		}
 	}
 	AST_LIST_UNLOCK(&peers);
-	if (!nummaps || !maps)
+	if (!nummaps) {
 		return -1;
+	}
 	ttlms = DUNDI_FLUFF_TIME + ttl * DUNDI_TTL_TIME;
 	memset(&dr2, 0, sizeof(dr2));
 	memset(&dr, 0, sizeof(dr));
diff --git a/pbx/pbx_lua.c b/pbx/pbx_lua.c
index 928861698..1b9182794 100644
--- a/pbx/pbx_lua.c
+++ b/pbx/pbx_lua.c
@@ -303,7 +303,7 @@ static int lua_get_variable_value(lua_State *L)
 {
 	struct ast_channel *chan;
 	char *value = NULL, *name;
-	char *workspace = alloca(LUA_BUF_SIZE);
+	char *workspace = ast_alloca(LUA_BUF_SIZE);
 	int autoservice;
 
 	workspace[0] = '\0';
@@ -561,7 +561,7 @@ static int lua_get_variable(lua_State *L)
 	struct ast_channel *chan;
 	const char *name = luaL_checkstring(L, 2);
 	char *value = NULL;
-	char *workspace = alloca(LUA_BUF_SIZE);
+	char *workspace = ast_alloca(LUA_BUF_SIZE);
 	workspace[0] = '\0';
 	
 	lua_getfield(L, LUA_REGISTRYINDEX, "channel");
@@ -1080,7 +1080,7 @@ static char *lua_read_extensions_file(lua_State *L, long *size)
 	FILE *f;
 	int error_func;
 	char *data;
-	char *path = alloca(strlen(config) + strlen(ast_config_AST_CONFIG_DIR) + 2);
+	char *path = ast_alloca(strlen(config) + strlen(ast_config_AST_CONFIG_DIR) + 2);
 	sprintf(path, "%s/%s", ast_config_AST_CONFIG_DIR, config);
 
 	if (!(f = fopen(path, "r"))) {
diff --git a/pbx/pbx_realtime.c b/pbx/pbx_realtime.c
index fb2f41320..3808483ad 100644
--- a/pbx/pbx_realtime.c
+++ b/pbx/pbx_realtime.c
@@ -228,52 +228,50 @@ static struct ast_variable *realtime_common(const char *context, const char *ext
 		char exten[AST_MAX_EXTENSION];
 	} cache_search = { { .priority = priority, .context = (char *) context }, };
 	char *buf = ast_strdupa(data);
-	if (buf) {
-		/* "Realtime" prefix is stripped off in the parent engine.  The
-		 * remaining string is: [[context@]table][/opts] */
-		char *opts = strchr(buf, '/');
-		if (opts)
-			*opts++ = '\0';
-		table = strchr(buf, '@');
-		if (table) {
-			*table++ = '\0';
-			ctx = buf;
-		}
-		ctx = S_OR(ctx, context);
-		table = S_OR(table, "extensions");
-		if (!ast_strlen_zero(opts)) {
-			ast_app_parse_options(switch_opts, &flags, NULL, opts);
-		}
-		ast_copy_string(cache_search.exten, exten, sizeof(cache_search.exten));
-		if (mode == MODE_MATCH && (ce = ao2_find(cache, &cache_search, OBJ_POINTER))) {
-			var = dup_vars(ce->var);
+	/* "Realtime" prefix is stripped off in the parent engine.  The
+	 * remaining string is: [[context@]table][/opts] */
+	char *opts = strchr(buf, '/');
+	if (opts)
+		*opts++ = '\0';
+	table = strchr(buf, '@');
+	if (table) {
+		*table++ = '\0';
+		ctx = buf;
+	}
+	ctx = S_OR(ctx, context);
+	table = S_OR(table, "extensions");
+	if (!ast_strlen_zero(opts)) {
+		ast_app_parse_options(switch_opts, &flags, NULL, opts);
+	}
+	ast_copy_string(cache_search.exten, exten, sizeof(cache_search.exten));
+	if (mode == MODE_MATCH && (ce = ao2_find(cache, &cache_search, OBJ_POINTER))) {
+		var = dup_vars(ce->var);
+		ao2_ref(ce, -1);
+	} else {
+		var = realtime_switch_common(table, ctx, exten, priority, mode, flags);
+		do {
+			struct ast_variable *new;
+			/* Only cache matches */
+			if (mode != MODE_MATCH) {
+				break;
+			}
+			if (!(new = dup_vars(var))) {
+				break;
+			}
+			if (!(ce = ao2_alloc(sizeof(*ce) + strlen(exten) + strlen(context), free_entry))) {
+				ast_variables_destroy(new);
+				break;
+			}
+			ce->context = ce->exten + strlen(exten) + 1;
+			strcpy(ce->exten, exten); /* SAFE */
+			strcpy(ce->context, context); /* SAFE */
+			ce->priority = priority;
+			ce->var = new;
+			ce->when = ast_tvnow();
+			ao2_link(cache, ce);
+			pthread_kill(cleanup_thread, SIGURG);
 			ao2_ref(ce, -1);
-		} else {
-			var = realtime_switch_common(table, ctx, exten, priority, mode, flags);
-			do {
-				struct ast_variable *new;
-				/* Only cache matches */
-				if (mode != MODE_MATCH) {
-					break;
-				}
-				if (!(new = dup_vars(var))) {
-					break;
-				}
-				if (!(ce = ao2_alloc(sizeof(*ce) + strlen(exten) + strlen(context), free_entry))) {
-					ast_variables_destroy(new);
-					break;
-				}
-				ce->context = ce->exten + strlen(exten) + 1;
-				strcpy(ce->exten, exten); /* SAFE */
-				strcpy(ce->context, context); /* SAFE */
-				ce->priority = priority;
-				ce->var = new;
-				ce->when = ast_tvnow();
-				ao2_link(cache, ce);
-				pthread_kill(cleanup_thread, SIGURG);
-				ao2_ref(ce, -1);
-			} while (0);
-		}
+		} while (0);
 	}
 	return var;
 }
@@ -315,7 +313,7 @@ static int realtime_exec(struct ast_channel *chan, const char *context, const ch
 				if (ast_compat_pbx_realtime) {
 					char *ptr;
 					int in = 0;
-					tmp = alloca(strlen(v->value) * 2 + 1);
+					tmp = ast_alloca(strlen(v->value) * 2 + 1);
 					for (ptr = tmp; *v->value; v->value++) {
 						if (*v->value == ',') {
 							*ptr++ = '\\';
diff --git a/pbx/pbx_spool.c b/pbx/pbx_spool.c
index e176b95c4..43bac620e 100644
--- a/pbx/pbx_spool.c
+++ b/pbx/pbx_spool.c
@@ -486,7 +486,7 @@ static void queue_file(const char *filename, time_t when)
 	time_t now = time(NULL);
 
 	if (filename[0] != '/') {
-		char *fn = alloca(strlen(qdir) + strlen(filename) + 2);
+		char *fn = ast_alloca(strlen(qdir) + strlen(filename) + 2);
 		sprintf(fn, "%s/%s", qdir, filename); /* SAFE */
 		filename = fn;
 	}