Changeset 65b48ee in code

Timestamp:

Apr 22, 2015, 5:29:05 PM (10 years ago)

Author:

Mike Belopuhov <mike@…>

Branches:

master

Children:

8b1683e

Parents:

7ff6405

Message:

Improve [v]snprintf return value handling

File:

• icb.c (modified) (6 diffs)

icb.c

@@ -256 +256 @@
         struct icb_group *ig = is->group;
         struct icb_session *s;
-        int buflen = 1;
+        int res, buflen = 1;
 
         if (strlen(msg) == 0) {
@@ -263 +263 @@
         }
 
-        buflen += snprintf(&buf[1], sizeof buf - 1, "%c%s%c%s", ICB_M_OPEN,
+        res = snprintf(&buf[1], sizeof buf - 1, "%c%s%c%s", ICB_M_OPEN,
             is->nick, ICB_M_SEP, msg);
+        if (res < 0) {
+                icb_error(is, "Format error");
+                return;
+        }
+        buflen += MIN((size_t)res, sizeof buf - 1);
         buf[0] = buflen;
 
@@ -373 +378 @@
         va_list ap;
         char buf[ICB_MSGSIZE];
-        int buflen = 1;
+        int res, buflen = 1;
         static const struct {
                 int              type;
@@ -395 +400 @@
         if (type < 0 || type > (int)nitems(msgtab) - 1)
                 return;
+        res = snprintf(&buf[1], sizeof buf - 1, "%c%s%c", ICB_M_STATUS,
+            msgtab[type].msg, ICB_M_SEP);
+        if (res < 0) {
+                icbd_log(NULL, LOG_ERR, "Format error in %s", __func__);
+                return;
+        }
+        buflen += MIN((size_t)res, sizeof buf - 1);
+        if ((size_t)buflen >= sizeof buf) {
+                icbd_log(NULL, LOG_ERR, "Status buffer too small");
+                return;
+        }
         va_start(ap, fmt);
-        buflen += snprintf(&buf[1], sizeof buf - 1, "%c%s%c", ICB_M_STATUS,
-            msgtab[type].msg, ICB_M_SEP);
-        buflen += vsnprintf(&buf[buflen], sizeof buf - buflen, fmt, ap);
+        res = vsnprintf(&buf[buflen], sizeof buf - buflen, fmt, ap);
+        va_end(ap);
+        if (res < 0) {
+                icbd_log(NULL, LOG_ERR, "Format error in %s", __func__);
+                return;
+        }
+        buflen += MIN((size_t)res, sizeof buf - buflen);
         buf[0] = buflen;
-        va_end(ap);
         icbd_send(is, buf, buflen + 1);
 }
@@ -436 +455 @@
         char buf[ICB_MSGSIZE];
         va_list ap;
-        int buflen = 1;
+        int res, buflen = 1;
 
         va_start(ap, fmt);
-        buflen += vsnprintf(&buf[2], sizeof buf - 2, fmt, ap);
+        res = vsnprintf(&buf[2], sizeof buf - 2, fmt, ap);
         va_end(ap);
+        if (res < 0) {
+                icbd_log(NULL, LOG_ERR, "Format error");
+                return;
+        }
+        buflen += MIN((size_t)res, sizeof buf - 2);
         buf[0] = ++buflen; /* account for ICB_M_ERROR */
         buf[1] = ICB_M_ERROR;
@@ -625 +649 @@
         char buf[ICB_MSGSIZE];
         va_list ap;
-        int buflen = 1;
+        int res, buflen = 1;
 
         va_start(ap, fmt);
-        buflen += vsnprintf(&buf[1], sizeof buf - 1, fmt, ap);
+        res = vsnprintf(&buf[1], sizeof buf - 1, fmt, ap);
         va_end(ap);
+        if (res < 0) {
+                icbd_log(NULL, LOG_ERR, "Format error in %s", __func__);
+                return;
+        }
+        buflen += MIN((size_t)res, sizeof buf - 1);
         buf[0] = buflen;
         icbd_send(is, buf, buflen + 1);