src/liboping.c: Use thread-safe error handling.

I. e. move to `strerror_r'.

diff --git a/configure.ac b/configure.ac
index 67bc892..984ad85 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -160,6 +160,8 @@ AC_CHECK_FUNCS(nanosleep, [],
                AC_MSG_ERROR(cannot find nanosleep)))
 AM_CONDITIONAL(BUILD_WITH_LIBRT, test "x$nanosleep_needs_rt" = "xyes")
 
+AC_FUNC_STRERROR_R
+
 AC_ARG_ENABLE(debug, [AS_HELP_STRING([--enable-debug], [Enable extensive debugging output.])],
 [
        if test "x$enable_debug" = "xyes"

diff --git a/src/liboping.c b/src/liboping.c
index c7bdaec..c64060c 100644 (file)
--- a/src/liboping.c
+++ b/src/liboping.c
@@ -137,11 +137,60 @@ struct pingobj
 /*
  * private (static) functions
  */
+/* Even though Posix requires "strerror_r" to return an "int",
+ * some systems (e.g. the GNU libc) return a "char *" _and_
+ * ignore the second argument ... -tokkee */
+char *sstrerror (int errnum, char *buf, size_t buflen)
+{
+       buf[0] = 0;
+
+#if !HAVE_STRERROR_R
+       {
+               snprintf (buf, buflen, "Error %i (%#x)", errnum, errnum);
+       }
+/* #endif !HAVE_STRERROR_R */
+
+#elif STRERROR_R_CHAR_P
+       {
+               char *temp;
+               temp = strerror_r (errnum, buf, buflen);
+               if (buf[0] == 0)
+               {
+                       if ((temp != NULL) && (temp != buf) && (temp[0] != 0))
+                               strncpy (buf, temp, buflen);
+                       else
+                               strncpy (buf, "strerror_r did not return "
+                                               "an error message", buflen);
+               }
+       }
+/* #endif STRERROR_R_CHAR_P */
+
+#else
+       if (strerror_r (errnum, buf, buflen) != 0)
+       {
+               snprintf (buf, buflen, "Error %i (%#x); "
+                               "Additionally, strerror_r failed.",
+                               errnum, errnum);
+       }
+#endif /* STRERROR_R_CHAR_P */
+
+       buf[buflen - 1] = 0;
+
+       return (buf);
+} /* char *sstrerror */
+
 static void ping_set_error (pingobj_t *obj, const char *function,
                const char *message)
 {
-       snprintf (obj->errmsg, PING_ERRMSG_LEN, "%s: %s", function, message);
-       obj->errmsg[PING_ERRMSG_LEN - 1] = '\0';
+       snprintf (obj->errmsg, sizeof (obj->errmsg),
+                       "%s: %s", function, message);
+       obj->errmsg[sizeof (obj->errmsg) - 1] = 0;
+}
+
+static void ping_set_errno (pingobj_t *obj, const char *function,
+               int error_number)
+{
+       sstrerror (error_number, obj->errmsg, sizeof (obj->errmsg));
 }
 
 static int ping_timeval_add (struct timeval *tv1, struct timeval *tv2,
@@ -390,7 +439,11 @@ static int ping_receive_one (int fd, pinghost_t *ph, struct timeval *now)
                        (struct sockaddr *) &sa, &sa_len);
        if (buffer_len < 0)
        {
-               dprintf ("recvfrom: %s\n", strerror (errno));
+#if WITH_DEBUG
+               char errbuf[PING_ERRMSG_LEN];
+               dprintf ("recvfrom: %s\n",
+                               sstrerror (errno, errbuf, sizeof (errbuf)));
+#endif
                return (-1);
        }
 
@@ -456,7 +509,7 @@ static int ping_receive_all (pingobj_t *obj)
 
        if (gettimeofday (&nowtime, NULL) == -1)
        {
-               ping_set_error (obj, "gettimeofday", strerror (errno));
+               ping_set_errno (obj, "gettimeofday", errno);
                return (-1);
        }
 
@@ -493,7 +546,7 @@ static int ping_receive_all (pingobj_t *obj)
 
                if (gettimeofday (&nowtime, NULL) == -1)
                {
-                       ping_set_error (obj, "gettimeofday", strerror (errno));
+                       ping_set_errno (obj, "gettimeofday", errno);
                        return (-1);
                }
 
@@ -508,7 +561,7 @@ static int ping_receive_all (pingobj_t *obj)
 
                if (gettimeofday (&nowtime, NULL) == -1)
                {
-                       ping_set_error (obj, "gettimeofday", strerror (errno));
+                       ping_set_errno (obj, "gettimeofday", errno);
                        return (-1);
                }
                
@@ -519,7 +572,11 @@ static int ping_receive_all (pingobj_t *obj)
                }
                else if (status < 0)
                {
-                       dprintf ("select: %s\n", strerror (errno));
+#if WITH_DEBUG
+                       char errbuf[PING_ERRMSG_LEN];
+                       dprintf ("select: %s\n",
+                                       sstrerror (errno, errbuf, sizeof (errbuf)));
+#endif
                        break;
                }
                else if (status == 0)
@@ -573,7 +630,7 @@ static ssize_t ping_sendto (pingobj_t *obj, pinghost_t *ph,
                if (errno == ENETUNREACH)
                        return (0);
 #endif
-               ping_set_error (obj, "sendto", strerror (errno));
+               ping_set_errno (obj, "sendto", errno);
        }
 
        return (ret);
@@ -685,7 +742,11 @@ static int ping_send_all (pingobj_t *obj)
                 * sending the packet, so I will do that too */
                if (gettimeofday (ptr->timer, NULL) == -1)
                {
-                       dprintf ("gettimeofday: %s\n", strerror (errno));
+#if WITH_DEBUG
+                       char errbuf[PING_ERRMSG_LEN];
+                       dprintf ("gettimeofday: %s\n",
+                                       sstrerror (errno, errbuf, sizeof (errbuf)));
+#endif
                        timerclear (ptr->timer);
                        ret--;
                        continue;
@@ -770,10 +831,14 @@ static int ping_get_ident (void)
 
                        close (fd);
                }
+#if WITH_DEBUG
                else
                {
-                       dprintf ("open (/dev/urandom): %s\n", strerror (errno));
+                       char errbuf[PING_ERRMSG_LEN];
+                       dprintf ("open (/dev/urandom): %s\n",
+                                       sstrerror (errno, errbuf, sizeof (errbuf)));
                }
+#endif
        }
 
        retval = (int) random ();
@@ -946,10 +1011,13 @@ int ping_setopt (pingobj_t *obj, int option, void *value)
                        status = getaddrinfo (hostname, NULL, &ai_hints, &ai_list);
                        if (status != 0)
                        {
+#if defined(EAI_SYSTEM)
+                               char errbuf[PING_ERRMSG_LEN];
+#endif
                                ping_set_error (obj, "getaddrinfo",
 #if defined(EAI_SYSTEM)
                                                (status == EAI_SYSTEM)
-                                               ? strerror (errno) :
+                                               ? sstrerror (errno, errbuf, sizeof (errbuf)) :
 #endif
                                                gai_strerror (status));
                                ret = -1;
@@ -967,8 +1035,7 @@ int ping_setopt (pingobj_t *obj, int option, void *value)
                                obj->srcaddr = (struct sockaddr_storage *) malloc (sizeof (struct sockaddr_storage));
                                if (obj->srcaddr == NULL)
                                {
-                                       ping_set_error (obj, "malloc",
-                                                       strerror (errno));
+                                       ping_set_errno (obj, "malloc", errno);
                                        ret = -1;
                                        freeaddrinfo (ai_list);
                                        break;
@@ -1055,7 +1122,7 @@ int ping_host_add (pingobj_t *obj, const char *host)
        if ((ph->username = strdup (host)) == NULL)
        {
                dprintf ("Out of memory!\n");
-               ping_set_error (obj, "strdup", strerror (errno));
+               ping_set_errno (obj, "strdup", errno);
                ping_free (ph);
                return (-1);
        }
@@ -1063,7 +1130,7 @@ int ping_host_add (pingobj_t *obj, const char *host)
        if ((ph->hostname = strdup (host)) == NULL)
        {
                dprintf ("Out of memory!\n");
-               ping_set_error (obj, "strdup", strerror (errno));
+               ping_set_errno (obj, "strdup", errno);
                ping_free (ph);
                return (-1);
        }
@@ -1072,18 +1139,21 @@ int ping_host_add (pingobj_t *obj, const char *host)
        if ((ph->data = strdup (obj->data == NULL ? PING_DEF_DATA : obj->data)) == NULL)
        {
                dprintf ("Out of memory!\n");
-               ping_set_error (obj, "strdup", strerror (errno));
+               ping_set_errno (obj, "strdup", errno);
                ping_free (ph);
                return (-1);
        }
 
        if ((ai_return = getaddrinfo (host, NULL, &ai_hints, &ai_list)) != 0)
        {
+#if defined(EAI_SYSTEM)
+               char errbuf[PING_ERRMSG_LEN];
+#endif
                dprintf ("getaddrinfo failed\n");
                ping_set_error (obj, "getaddrinfo",
 #if defined(EAI_SYSTEM)
                                                (ai_return == EAI_SYSTEM)
-                                               ? strerror (errno) :
+                                               ? sstrerror (errno, errbuf, sizeof (errbuf)) :
 #endif
                                gai_strerror (ai_return));
                ping_free (ph);
@@ -1141,8 +1211,12 @@ int ping_host_add (pingobj_t *obj, const char *host)
                ph->fd = socket (ai_ptr->ai_family, ai_ptr->ai_socktype, ai_ptr->ai_protocol);
                if (ph->fd == -1)
                {
-                       dprintf ("socket: %s\n", strerror (errno));
-                       ping_set_error (obj, "socket", strerror (errno));
+#if WITH_DEBUG
+                       char errbuf[PING_ERRMSG_LEN];
+                       dprintf ("socket: %s\n",
+                                       sstrerror (errno, errbuf, sizeof (errbuf)));
+#endif
+                       ping_set_errno (obj, "socket", errno);
                        continue;
                }
 
@@ -1153,8 +1227,12 @@ int ping_host_add (pingobj_t *obj, const char *host)
 
                        if (bind (ph->fd, (struct sockaddr *) obj->srcaddr, obj->srcaddrlen) == -1)
                        {
-                               dprintf ("bind: %s\n", strerror (errno));
-                               ping_set_error (obj, "bind", strerror (errno));
+#if WITH_DEBUG
+                               char errbuf[PING_ERRMSG_LEN];
+                               dprintf ("bind: %s\n",
+                                               sstrerror (errno, errbuf, sizeof (errbuf)));
+#endif
+                               ping_set_errno (obj, "bind", errno);
                                close (ph->fd);
                                ph->fd = -1;
                                continue;