Check return value of snprintf().

This should fix https://github.com/sctplab/usrsctp/issues/453.

11 files changed, 56 insertions, 26 deletions

diff --git a/programs/daytime_server.c b/programs/daytime_server.c
index 3e03dc1f..cab27554 100644
--- a/programs/daytime_server.c
+++ b/programs/daytime_server.c
@@ -111,10 +111,12 @@ main(int argc, char *argv[])
 		}
 		time(&now);
 #ifdef _WIN32
-		_snprintf(buffer, sizeof(buffer), "%s", ctime(&now));
+		if (_snprintf(buffer, sizeof(buffer), "%s", ctime(&now)) < 0) {
 #else
-		snprintf(buffer, sizeof(buffer), "%s", ctime(&now));
+		if (snprintf(buffer, sizeof(buffer), "%s", ctime(&now)) < 0) {
 #endif
+			buffer[0] = '\0';
+		}
 		sndinfo.snd_sid = 0;
 		sndinfo.snd_flags = 0;
 		sndinfo.snd_ppid = htonl(DAYTIME_PPID);
diff --git a/programs/daytime_server_upcall.c b/programs/daytime_server_upcall.c
index b85cb256..87017cf2 100644
--- a/programs/daytime_server_upcall.c
+++ b/programs/daytime_server_upcall.c
@@ -69,10 +69,12 @@ handle_accept(struct socket *sock, void *data, int flags)
 	}
 	time(&now);
 #ifdef _WIN32
-		_snprintf(buffer, sizeof(buffer), "%s", ctime(&now));
+		if (_snprintf(buffer, sizeof(buffer), "%s", ctime(&now)) < 0) {
 #else
-		snprintf(buffer, sizeof(buffer), "%s", ctime(&now));
+		if (snprintf(buffer, sizeof(buffer), "%s", ctime(&now)) < 0) {
 #endif
+			buffer[0] = '\0';
+		}
 		sndinfo.snd_sid = 0;
 		sndinfo.snd_flags = 0;
 		sndinfo.snd_ppid = htonl(DAYTIME_PPID);
diff --git a/programs/discard_server.c b/programs/discard_server.c
index e469b363..b60c6921 100644
--- a/programs/discard_server.c
+++ b/programs/discard_server.c
@@ -86,10 +86,12 @@ receive_cb(struct socket *sock, union sctp_sockstore addr, void *data,
 #endif
 			case AF_CONN:
 #ifdef _WIN32
-				_snprintf(namebuf, INET6_ADDRSTRLEN, "%p", addr.sconn.sconn_addr);
+				if (_snprintf(namebuf, INET6_ADDRSTRLEN, "%p", addr.sconn.sconn_addr) < 0) {
 #else
-				snprintf(namebuf, INET6_ADDRSTRLEN, "%p", addr.sconn.sconn_addr);
+				if (snprintf(namebuf, INET6_ADDRSTRLEN, "%p", addr.sconn.sconn_addr) < 0) {
 #endif
+					namebuf[0] = '\0';
+				}
 				name = namebuf;
 				port = ntohs(addr.sconn.sconn_port);
 				break;
diff --git a/programs/echo_server.c b/programs/echo_server.c
index f59a99c8..38fa6f41 100644
--- a/programs/echo_server.c
+++ b/programs/echo_server.c
@@ -86,10 +86,12 @@ receive_cb(struct socket *sock, union sctp_sockstore addr, void *data,
 #endif
 			case AF_CONN:
 #ifdef _WIN32
-				_snprintf(namebuf, INET6_ADDRSTRLEN, "%p", addr.sconn.sconn_addr);
+				if (_snprintf(namebuf, INET6_ADDRSTRLEN, "%p", addr.sconn.sconn_addr) < 0) {
 #else
-				snprintf(namebuf, INET6_ADDRSTRLEN, "%p", addr.sconn.sconn_addr);
+				if (snprintf(namebuf, INET6_ADDRSTRLEN, "%p", addr.sconn.sconn_addr) < 0) {
 #endif
+					namebuf[0] = '\0';
+				}
 				name = namebuf;
 				port = ntohs(addr.sconn.sconn_port);
 				break;
diff --git a/programs/ekr_loop_upcall.c b/programs/ekr_loop_upcall.c
index d225fee9..717dfce5 100644
--- a/programs/ekr_loop_upcall.c
+++ b/programs/ekr_loop_upcall.c
@@ -121,7 +121,9 @@ conn_output(void *addr, void *buf, size_t length, uint8_t tos, uint8_t set_df)
 	FILE *fp;
 	char fname[128];
 	static int pktnum = 0;
-	snprintf(fname, sizeof(fname), "pkt-%d", pktnum++);
+	if (snprintf(fname, sizeof(fname), "pkt-%d", pktnum++) < 0) {
+		fname[0] = '\0';
+	}
 	fp = fopen(fname, "wb");
 	fwrite((char *)buf + 12, 1, length - 12, fp);
 	fclose(fp);
diff --git a/programs/http_client.c b/programs/http_client.c
index def03849..03c92860 100644
--- a/programs/http_client.c
+++ b/programs/http_client.c
@@ -256,16 +256,20 @@ main(int argc, char *argv[])
 
 	if (argc > 6) {
 #ifdef _WIN32
-		_snprintf(request, sizeof(request), "%s %s %s", request_prefix, argv[6], request_postfix);
+		if (_snprintf(request, sizeof(request), "%s %s %s", request_prefix, argv[6], request_postfix) < 0) {
 #else
-		snprintf(request, sizeof(request), "%s %s %s", request_prefix, argv[6], request_postfix);
+		if (snprintf(request, sizeof(request), "%s %s %s", request_prefix, argv[6], request_postfix) < 0) {
 #endif
+			request[0] = '\0';
+		}
 	} else {
 #ifdef _WIN32
-		_snprintf(request, sizeof(request), "%s %s %s", request_prefix, "/", request_postfix);
+		if (_snprintf(request, sizeof(request), "%s %s %s", request_prefix, "/", request_postfix) < 0) {
 #else
-		snprintf(request, sizeof(request), "%s %s %s", request_prefix, "/", request_postfix);
+		if (snprintf(request, sizeof(request), "%s %s %s", request_prefix, "/", request_postfix) < 0) {
 #endif
+			request[0] = '\0';
+		}
 	}
 
 	printf("\nHTTP request:\n%s\n", request);
diff --git a/programs/http_client_upcall.c b/programs/http_client_upcall.c
index 5583b54c..63916266 100644
--- a/programs/http_client_upcall.c
+++ b/programs/http_client_upcall.c
@@ -276,16 +276,20 @@ main(int argc, char *argv[])
 
 	if (argc > 6) {
 #ifdef _WIN32
-		_snprintf(request, sizeof(request), "%s %s %s", request_prefix, argv[6], request_postfix);
+		if (_snprintf(request, sizeof(request), "%s %s %s", request_prefix, argv[6], request_postfix) < 0) {
 #else
-		snprintf(request, sizeof(request), "%s %s %s", request_prefix, argv[6], request_postfix);
+		if (snprintf(request, sizeof(request), "%s %s %s", request_prefix, argv[6], request_postfix) < 0) {
 #endif
+			request[0] = '\0';
+		}
 	} else {
 #ifdef _WIN32
-		_snprintf(request, sizeof(request), "%s %s %s", request_prefix, "/", request_postfix);
+		if (_snprintf(request, sizeof(request), "%s %s %s", request_prefix, "/", request_postfix) < 0) {
 #else
-		snprintf(request, sizeof(request), "%s %s %s", request_prefix, "/", request_postfix);
+		if (snprintf(request, sizeof(request), "%s %s %s", request_prefix, "/", request_postfix) < 0) {
 #endif
+			request[0] = '\0';
+		}
 	}
 
 	printf("\nHTTP request:\n%s\n", request);
diff --git a/programs/programs_helper.c b/programs/programs_helper.c
index 0883740f..a8dbd62f 100644
--- a/programs/programs_helper.c
+++ b/programs/programs_helper.c
@@ -65,8 +65,9 @@ debug_printf_stack(const char *format, ...)
 	timersub(&time_now, &time_main, &time_delta);
 
 	va_start(ap, format);
-	//vfprintf(stderr, format, ap);
-	vsnprintf(charbuf, 1024, format, ap);
+	if (vsnprintf(charbuf, 1024, format, ap) < 0) {
+		charbuf[0] = '\0';
+	}
 	va_end(ap);
 
 	fprintf(stderr, "[S][%u.%03u] %s", (unsigned int) time_delta.tv_sec, (unsigned int) time_delta.tv_usec / 1000, charbuf);
@@ -158,18 +159,22 @@ handle_peer_address_change_event(struct sctp_paddr_change *spc)
 	case AF_CONN:
 		sconn = (struct sockaddr_conn *)&spc->spc_aaddr;
 #ifdef _WIN32
-		_snprintf(addr_buf, INET6_ADDRSTRLEN, "%p", sconn->sconn_addr);
+		if (_snprintf(addr_buf, INET6_ADDRSTRLEN, "%p", sconn->sconn_addr) < 0) {
 #else
-		snprintf(addr_buf, INET6_ADDRSTRLEN, "%p", sconn->sconn_addr);
+		if (snprintf(addr_buf, INET6_ADDRSTRLEN, "%p", sconn->sconn_addr) < 0) {
 #endif
+			addr_buf[0] = '\0';
+		}
 		addr = addr_buf;
 		break;
 	default:
 #ifdef _WIN32
-		_snprintf(addr_buf, INET6_ADDRSTRLEN, "Unknown family %d", spc->spc_aaddr.ss_family);
+		if (_snprintf(addr_buf, INET6_ADDRSTRLEN, "Unknown family %d", spc->spc_aaddr.ss_family) < 0) {
 #else
-		snprintf(addr_buf, INET6_ADDRSTRLEN, "Unknown family %d", spc->spc_aaddr.ss_family);
+		if (snprintf(addr_buf, INET6_ADDRSTRLEN, "Unknown family %d", spc->spc_aaddr.ss_family) < 0) {
 #endif
+			addr_buf[0] = '\0';
+		}
 		addr = addr_buf;
 		break;
 	}
diff --git a/programs/rtcweb.c b/programs/rtcweb.c
index 1bf3b182..e0d3684a 100644
--- a/programs/rtcweb.c
+++ b/programs/rtcweb.c
@@ -927,10 +927,12 @@ handle_peer_address_change_event(struct sctp_paddr_change *spc)
 		break;
 	default:
 #ifdef _WIN32
-		_snprintf(addr_buf, INET6_ADDRSTRLEN, "Unknown family %d", spc->spc_aaddr.ss_family);
+		if (_snprintf(addr_buf, INET6_ADDRSTRLEN, "Unknown family %d", spc->spc_aaddr.ss_family) < 0) {
 #else
-		snprintf(addr_buf, INET6_ADDRSTRLEN, "Unknown family %d", spc->spc_aaddr.ss_family);
+		if (snprintf(addr_buf, INET6_ADDRSTRLEN, "Unknown family %d", spc->spc_aaddr.ss_family) < 0) {
 #endif
+			addr_buf[0] = '\0';
+		}
 		addr = addr_buf;
 		break;
 	}
diff --git a/programs/st_client.c b/programs/st_client.c
index da5c53bc..49250bce 100644
--- a/programs/st_client.c
+++ b/programs/st_client.c
@@ -137,6 +137,9 @@ on_connect(struct socket* s)
 	/* memset(buffer, 'A', BUFFER_SIZE); */
 	/* bufferlen = BUFFER_SIZE; */
 	bufferlen = snprintf(buffer, BUFFER_SIZE, "GET / HTTP/1.0\r\nUser-agent: libusrsctp\r\nConnection: close\r\n\r\n");
+	if (bufferlen < 0) {
+		return;
+	}
 	sndinfo.snd_sid = 0;
 	sndinfo.snd_flags = 0;
 	sndinfo.snd_ppid = htonl(DISCARD_PPID);
diff --git a/programs/tsctp_upcall.c b/programs/tsctp_upcall.c
index fab56891..21f6bba9 100644
--- a/programs/tsctp_upcall.c
+++ b/programs/tsctp_upcall.c
@@ -151,7 +151,9 @@ static const char *bytes2human(uint64_t bytes)
 		}
 	}
 
-	snprintf(output, sizeof(output), "%.02lf %s", human_size, suffix[i]);
+	if (snprintf(output, sizeof(output), "%.02lf %s", human_size, suffix[i]) < 0) {
+		output[0] = '\0';
+	}
 	return output;
 }