Changeset 4613 for pjproject/trunk/pjmedia/src/pjmedia-audiodev/alsa_dev.c

Timestamp:

Oct 8, 2013 9:08:13 AM (11 years ago)

Author:

bennylp

Message:

Re #1703: fixing general bugs. First installment: correct handling of snprintf return value

File:

• pjproject/trunk/pjmedia/src/pjmedia-audiodev/alsa_dev.c (modified) (2 diffs)

pjproject/trunk/pjmedia/src/pjmedia-audiodev/alsa_dev.c

@@ -172 +172 @@
 {
     char err_msg[128];
-    int index;
+    int index, len;
     va_list arg;
 
@@ -181 +181 @@
     index = snprintf (err_msg, sizeof(err_msg), "ALSA lib: ");
 #endif
+    if (index < 1 || index >= (int)sizeof(err_msg)) {
+        index = sizeof(err_msg)-1;
+        err_msg[index] = '\0';
+        goto print_msg;
+    }
+
     va_start (arg, fmt);
-    if (index < sizeof(err_msg)-1)
-        index += vsnprintf (err_msg+index, sizeof(err_msg)-index, fmt, arg);
+    if (index < sizeof(err_msg)-1) {
+        len = vsnprintf( err_msg+index, sizeof(err_msg)-index, fmt, arg);
+        if (len < 1 || len >= (int)sizeof(err_msg)-index)
+            len = sizeof(err_msg)-index-1;
+        index += len;
+        err_msg[index] = '\0';
+    }
     va_end(arg);
-    if (err && index < sizeof(err_msg)-1)
-        index += snprintf (err_msg+index, sizeof(err_msg)-index, ": %s",
-                           snd_strerror(err));
+    if (err && index < sizeof(err_msg)-1) {
+        len = snprintf( err_msg+index, sizeof(err_msg)-index, ": %s",
+                        snd_strerror(err));
+        if (len < 1 || len >= (int)sizeof(err_msg)-index)
+            len = sizeof(err_msg)-index-1;
+        index += len;
+        err_msg[index] = '\0';
+    }
+print_msg:
     PJ_LOG (4,(THIS_FILE, "%s", err_msg));
 }