[M] Change in osmo-mgw[master]: mgcp_client: simpler error handling

30 Mar 2023

neels has uploaded this change for review. ( https://gerrit.osmocom.org/c/osmo-mgw/+/32162 )
Change subject: mgcp_client: simpler error handling
......................................................................
mgcp_client: simpler error handling
add_sdp(), add_lco():
- do not msgb_free() within these functions. Just return error, and move
  the msgb_free() to the caler.
- when failing to write to the msgb, directly return error.
Change-Id: I904d56f56053952c2ebbbe5dca744fafa32b333e
---
M src/libosmo-mgcp-client/mgcp_client.c
1 file changed, 56 insertions(+), 54 deletions(-)
git pull ssh://gerrit.osmocom.org:29418/osmo-mgw refs/changes/62/32162/1

diff --git a/src/libosmo-mgcp-client/mgcp_client.c b/src/libosmo-mgcp-client/mgcp_client.c
index 670910b..fb4c17a 100644
--- a/src/libosmo-mgcp-client/mgcp_client.c
+++ b/src/libosmo-mgcp-client/mgcp_client.c
@@ -1131,47 +1131,43 @@
 #define MGCP_AUEP_MANDATORY (MGCP_MSG_PRESENCE_ENDPOINT)
 #define MGCP_RSIP_MANDATORY 0	/* none */
+#define MSGB_PRINTF_OR_RET(msg, FMT, ARGS...) \
+	if (msgb_printf(msg, FMT, ##ARGS) != 0) { \
+		LOGP(DLMGCP, LOGL_ERROR, "Message buffer to small, can not generate MGCP/SDP message\n"); \
+		return -ENOBUFS; \
+	}
+
 /* Helper function for mgcp_msg_gen(): Add LCO information to MGCP message */
 static int add_lco(struct msgb *msg, struct mgcp_msg *mgcp_msg)
 {
    unsigned int i;
-	int rc = 0;
    const char *codec;
    unsigned int pt;
-	rc |= msgb_printf(msg, "L:");
+	MSGB_PRINTF_OR_RET(msg, "L:");
if (mgcp_msg->ptime)
-		rc |= msgb_printf(msg, " p:%u,", mgcp_msg->ptime);
+		MSGB_PRINTF_OR_RET(msg, " p:%u,", mgcp_msg->ptime);
if (mgcp_msg->codecs_len) {
-		rc |= msgb_printf(msg, " a:");
+		MSGB_PRINTF_OR_RET(msg, " a:");
    	for (i = 0; i < mgcp_msg->codecs_len; i++) {
    		pt = mgcp_msg->codecs[i];
    		codec = get_value_string_or_null(osmo_mgcpc_codec_names, pt);
/* Note: Use codec descriptors from enum mgcp_codecs
    		 * in mgcp_client only! */
-			if (!codec) {
-				msgb_free(msg);
+			if (!codec)
    			return -EINVAL;
-			}
-			rc |= msgb_printf(msg, "%s", extract_codec_name(codec));
+			MSGB_PRINTF_OR_RET(msg, "%s", extract_codec_name(codec));
    		if (i < mgcp_msg->codecs_len - 1)
-				rc |= msgb_printf(msg, ";");
+				MSGB_PRINTF_OR_RET(msg, ";");
    	}
-		rc |= msgb_printf(msg, ",");
+		MSGB_PRINTF_OR_RET(msg, ",");
    }
-	rc |= msgb_printf(msg, " nt:IN\r\n");
-
-	if (rc != 0) {
-		LOGP(DLMGCP, LOGL_ERROR,
-		     "message buffer to small, can not generate MGCP message (LCO)\n");
-		msgb_free(msg);
-		return -ENOBUFS;
-	}
+	MSGB_PRINTF_OR_RET(msg, " nt:IN\r\n");
    return 0;
 }
@@ -1179,43 +1175,37 @@
 static int add_sdp(struct msgb *msg, struct mgcp_msg *mgcp_msg, struct mgcp_client *mgcp)
 {
    unsigned int i;
-	int rc = 0;
    char local_ip[INET6_ADDRSTRLEN];
    int local_ip_family, audio_ip_family;
    const char *codec;
    unsigned int pt;
/* Add separator to mark the beginning of the SDP block */
-	rc |= msgb_printf(msg, "\r\n");
+	MSGB_PRINTF_OR_RET(msg, "\r\n");
/* Add SDP protocol version */
-	rc |= msgb_printf(msg, "v=0\r\n");
+	MSGB_PRINTF_OR_RET(msg, "v=0\r\n");
/* Determine local IP-Address */
    if (osmo_sock_local_ip(local_ip, mgcp->actual.remote_addr) < 0) {
    	LOGPMGW(mgcp, LOGL_ERROR,
    		"Could not determine local IP-Address!\n");
-		msgb_free(msg);
    	return -EINVAL;
    }
    local_ip_family = osmo_ip_str_type(local_ip);
-	if (local_ip_family == AF_UNSPEC) {
-		msgb_free(msg);
+	if (local_ip_family == AF_UNSPEC)
    	return -EINVAL;
-	}
    audio_ip_family = osmo_ip_str_type(mgcp_msg->audio_ip);
-	if (audio_ip_family == AF_UNSPEC) {
-		msgb_free(msg);
+	if (audio_ip_family == AF_UNSPEC)
    	return -EINVAL;
-	}
/* Add owner/creator (SDP) */
-	rc |= msgb_printf(msg, "o=- %x 23 IN IP%c %s\r\n", mgcp_msg->call_id,
+	MSGB_PRINTF_OR_RET(msg, "o=- %x 23 IN IP%c %s\r\n", mgcp_msg->call_id,
    		  local_ip_family == AF_INET6 ? '6' : '4',
    		  local_ip);
/* Add session name (none) */
-	rc |= msgb_printf(msg, "s=-\r\n");
+	MSGB_PRINTF_OR_RET(msg, "s=-\r\n");
/* Add RTP address and port */
    if (mgcp_msg->audio_port == 0) {
@@ -1230,20 +1220,20 @@
    	msgb_free(msg);
    	return -EINVAL;
    }
-	rc |= msgb_printf(msg, "c=IN IP%c %s\r\n",
+	MSGB_PRINTF_OR_RET(msg, "c=IN IP%c %s\r\n",
    		  audio_ip_family == AF_INET6 ? '6' : '4',
    		  mgcp_msg->audio_ip);
/* Add time description, active time (SDP) */
-	rc |= msgb_printf(msg, "t=0 0\r\n");
+	MSGB_PRINTF_OR_RET(msg, "t=0 0\r\n");
-	rc |= msgb_printf(msg, "m=audio %u RTP/AVP", mgcp_msg->audio_port);
+	MSGB_PRINTF_OR_RET(msg, "m=audio %u RTP/AVP", mgcp_msg->audio_port);
    for (i = 0; i < mgcp_msg->codecs_len; i++) {
    	pt = map_codec_to_pt(mgcp_msg->ptmap, mgcp_msg->ptmap_len, mgcp_msg->codecs[i]);
-		rc |= msgb_printf(msg, " %u", pt);
+		MSGB_PRINTF_OR_RET(msg, " %u", pt);
}
-	rc |= msgb_printf(msg, "\r\n");
+	MSGB_PRINTF_OR_RET(msg, "\r\n");
/* Add optional codec parameters (fmtp) */
    if (mgcp_msg->param_present) {
@@ -1253,9 +1243,9 @@
    			   continue;
    		pt = map_codec_to_pt(mgcp_msg->ptmap, mgcp_msg->ptmap_len, mgcp_msg->codecs[i]);
    		if (mgcp_msg->param.amr_octet_aligned_present && mgcp_msg->param.amr_octet_aligned)
-				rc |= msgb_printf(msg, "a=fmtp:%u octet-align=1\r\n", pt);
+				MSGB_PRINTF_OR_RET(msg, "a=fmtp:%u octet-align=1\r\n", pt);
    		else if (mgcp_msg->param.amr_octet_aligned_present && !mgcp_msg->param.amr_octet_aligned)
-				rc |= msgb_printf(msg, "a=fmtp:%u octet-align=0\r\n", pt);
+				MSGB_PRINTF_OR_RET(msg, "a=fmtp:%u octet-align=0\r\n", pt);
    	}
    }
@@ -1275,18 +1265,12 @@
    			return -EINVAL;
    		}
-			rc |= msgb_printf(msg, "a=rtpmap:%u %s\r\n", pt, codec);
+			MSGB_PRINTF_OR_RET(msg, "a=rtpmap:%u %s\r\n", pt, codec);
    	}
    }
if (mgcp_msg->ptime)
-		rc |= msgb_printf(msg, "a=ptime:%u\r\n", mgcp_msg->ptime);
-
-	if (rc != 0) {
-		LOGPMGW(mgcp, LOGL_ERROR, "Message buffer to small, can not generate MGCP message (SDP)\n");
-		msgb_free(msg);
-		return -ENOBUFS;
-	}
+		MSGB_PRINTF_OR_RET(msg, "a=ptime:%u\r\n", mgcp_msg->ptime);
return 0;
 }
@@ -1311,23 +1295,23 @@
    switch (mgcp_msg->verb) {
    case MGCP_VERB_CRCX:
    	mandatory_mask = MGCP_CRCX_MANDATORY;
-		rc |= msgb_printf(msg, "CRCX %u", trans_id);
+		MSGB_PRINTF_OR_RET(msg, "CRCX %u", trans_id);
    	break;
    case MGCP_VERB_MDCX:
    	mandatory_mask = MGCP_MDCX_MANDATORY;
-		rc |= msgb_printf(msg, "MDCX %u", trans_id);
+		MSGB_PRINTF_OR_RET(msg, "MDCX %u", trans_id);
    	break;
    case MGCP_VERB_DLCX:
    	mandatory_mask = MGCP_DLCX_MANDATORY;
-		rc |= msgb_printf(msg, "DLCX %u", trans_id);
+		MSGB_PRINTF_OR_RET(msg, "DLCX %u", trans_id);
    	break;
    case MGCP_VERB_AUEP:
    	mandatory_mask = MGCP_AUEP_MANDATORY;
-		rc |= msgb_printf(msg, "AUEP %u", trans_id);
+		MSGB_PRINTF_OR_RET(msg, "AUEP %u", trans_id);
    	break;
    case MGCP_VERB_RSIP:
    	mandatory_mask = MGCP_RSIP_MANDATORY;
-		rc |= msgb_printf(msg, "RSIP %u", trans_id);
+		MSGB_PRINTF_OR_RET(msg, "RSIP %u", trans_id);
    	break;
    default:
    	LOGPMGW(mgcp, LOGL_ERROR, "Invalid command verb, can not generate MGCP message\n");
@@ -1359,15 +1343,15 @@
    		return NULL;
    	}
-		rc |= msgb_printf(msg, " %s", mgcp_msg->endpoint);
+		MSGB_PRINTF_OR_RET(msg, " %s", mgcp_msg->endpoint);
    }
/* Add protocol version */
-	rc |= msgb_printf(msg, " MGCP 1.0\r\n");
+	MSGB_PRINTF_OR_RET(msg, " MGCP 1.0\r\n");
/* Add call id */
    if (mgcp_msg->presence & MGCP_MSG_PRESENCE_CALL_ID)
-		rc |= msgb_printf(msg, "C: %x\r\n", mgcp_msg->call_id);
+		MSGB_PRINTF_OR_RET(msg, "C: %x\r\n", mgcp_msg->call_id);
/* Add connection id */
    if (mgcp_msg->presence & MGCP_MSG_PRESENCE_CONN_ID) {
@@ -1376,7 +1360,7 @@
    		msgb_free(msg);
    		return NULL;
    	}
-		rc |= msgb_printf(msg, "I: %s\r\n", mgcp_msg->conn_id);
+		MSGB_PRINTF_OR_RET(msg, "I: %s\r\n", mgcp_msg->conn_id);
    }
/* Using SDP makes sense when a valid IP/Port combination is specifiec,
@@ -1391,6 +1375,7 @@
    	|| mgcp_msg->verb == MGCP_VERB_MDCX)) {
    	if (add_lco(msg, mgcp_msg) < 0) {
    		LOGPMGW(mgcp, LOGL_ERROR, "Failed to add LCO, can not generate MGCP message\n");
+			msgb_free(msg);
    		return NULL;
    	}
    }
@@ -1429,6 +1414,7 @@
    	|| mgcp_msg->verb == MGCP_VERB_MDCX)) {
    	if (add_sdp(msg, mgcp_msg, mgcp) < 0) {
    		LOGPMGW(mgcp, LOGL_ERROR, "Failed to add SDP, can not generate MGCP message\n");
+			msgb_free(msg);
    		return NULL;
    	}
    }
-- 
To view, visit https://gerrit.osmocom.org/c/osmo-mgw/+/32162
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Gerrit-Project: osmo-mgw
Gerrit-Branch: master
Gerrit-Change-Id: I904d56f56053952c2ebbbe5dca744fafa32b333e
Gerrit-Change-Number: 32162
Gerrit-PatchSet: 1
Gerrit-Owner: neels nhofmeyr@sysmocom.de
Gerrit-MessageType: newchange



    

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[M] Change in osmo-mgw[master]: mgcp_client: simpler error handling