Red Hat issue 1021948: snprintf API change

CHANGES

@@ -62,6 +62,11 @@ porting:
 	use getgrouplist() when available instead of sequence of calls to
 	getgrent()
 
+	Red Hat issue 1021948: snprintf API change;
+	Implemented xio_snprintf() function as wrapper that tries to emulate C99
+	behaviour on old glibc systems, and adapted all affected calls
+	appropriately
+
 docu:
 	libwrap always logs to syslog
 

compat.h

@@ -1,5 +1,5 @@
 /* source: compat.h */
-/* Copyright Gerhard Rieger 2001-2011 */
+/* Copyright Gerhard Rieger */
 /* Published under the GNU General Public License V.2, see file COPYING */
 
 #ifndef __compat_h_included
@@ -622,34 +622,4 @@
 extern const char *hstrerror(int);
 #endif
 
-/*****************************************************************************/
-/* here are the declarations of compat.c */
-
-#if !HAVE_SIGACTION
-struct sigaction {
-   void (*sa_handler)(int);
-   void (*sa_sigaction)(int, siginfo_t *, void *);
-   sigset_t sa_mask;
-   int sa_flags;
-} ;
-struct siginfo {
-   int si_signo;
-   int si_errno;
-   int si_code;
-   pid_t si_pid;
-   uid_t si_uid;
-   int   si_status;
-   /*clock_t si_utime;*/
-   /*clock_t si_stime;*/
-   sigval_t si_value;
-   int      si_int;
-   void    *si_ptr;
-   void    *si_addr;
-   /*int      si_band;*/
-   /*int      si_fd;*/
-} ;
-extern int sigaction(int signum, const struct sigaction *act,
-		     struct sigaction *oldact);
-#endif /* !HAVE_SIGACTION */
-
 #endif /* !defined(__compat_h_included) */

config.h.in

@@ -439,6 +439,9 @@
 /* is uint64_t already defined? */
 #undef HAVE_TYPE_UINT64
 
+/* Define if snprintf() returns required len on truncation (C-99 conform) */
+#undef HAVE_C99_SNPRINTF
+
 /* Define if you have the printf "Z" modifier */
 #undef HAVE_FORMAT_Z
 

configure.in

@@ -1284,11 +1284,29 @@ AC_CHECK_FUNC(SSLv2_server_method, AC_DEFINE(HAVE_SSLv2_server_method), AC_CHECK
 dnl Run time checks
 
 
+AC_MSG_CHECKING(if snprintf conforms to C99)
+AC_CACHE_VAL(ac_cv_have_c99_snprintf,
+[AC_TRY_RUN([
+#include <stdio.h>
+#include <stdlib.h>
+int main(void){
+char s[2];
+exit(snprintf(s,2,"ab")!=2);
+}],
+[ac_cv_have_c99_snprintf=yes],
+[ac_cv_have_c99_snprintf=no],
+[ac_cv_have_c99_snprintf=no])])
+if test $ac_cv_have_c99_snprintf = yes; then
+   AC_DEFINE(HAVE_C99_SNPRINTF)
+fi
+AC_MSG_RESULT($ac_cv_have_c99_snprintf)
+
+
 AC_MSG_CHECKING(if printf has Z modifier)
 AC_CACHE_VAL(ac_cv_have_z_modifier,
 [AC_TRY_RUN([
 #include <stdio.h>
-main(){
+int main(void){
 char s[16];
 sprintf(s,"%Zu",1);
 exit(strcmp(s,"1"));

sysutils.c

@@ -173,14 +173,16 @@ char *sockaddr_info(const struct sockaddr *sa, socklen_t salen, char *buff, size
    int n;
 
 #if HAVE_STRUCT_SOCKADDR_SALEN
-   if ((n = snprintf(cp, blen, "LEN=%d ", sau->soa.sa_len)) < 0) {
+   n = xio_snprintf(cp, blen, "LEN=%d ", sau->soa.sa_len);
+   if (n < 0 || n >= blen) {
       Warn1("sockaddr_info(): buffer too short ("F_Zu")", blen);
       *buff = '\0';
       return buff;
    }
    cp += n,  blen -= n;
 #endif
-   if ((n = snprintf(cp, blen, "AF=%d ", sau->soa.sa_family)) < 0) {
+   n = xio_snprintf(cp, blen, "AF=%d ", sau->soa.sa_family);
+   if (n < 0 || n >= blen) {
       Warn1("sockaddr_info(): buffer too short ("F_Zu")", blen);
       *buff = '\0';
       return buff;
@@ -204,13 +206,14 @@ char *sockaddr_info(const struct sockaddr *sa, socklen_t salen, char *buff, size
       break;
 #endif
    default:
-      if ((n = snprintf(cp, blen, "AF=%d ", sa->sa_family)) < 0) {
+      n = xio_snprintf(cp, blen, "AF=%d ", sa->sa_family);
+      if (n < 0 || n >= blen) {
 	 Warn1("sockaddr_info(): buffer too short ("F_Zu")", blen);
 	 *buff = '\0';
 	 return buff;
       }
       cp += n,  blen -= n;
-      if ((snprintf(cp, blen,
+      n = xio_snprintf(cp, blen,
 		    "0x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x",
 		    ((unsigned char *)sau->soa.sa_data)[0],
 		    ((unsigned char *)sau->soa.sa_data)[1],
@@ -225,7 +228,8 @@ char *sockaddr_info(const struct sockaddr *sa, socklen_t salen, char *buff, size
 		    ((unsigned char *)sau->soa.sa_data)[10],
 		    ((unsigned char *)sau->soa.sa_data)[11],
 		    ((unsigned char *)sau->soa.sa_data)[12],
-		    ((unsigned char *)sau->soa.sa_data)[13])) < 0) {
+		   ((unsigned char *)sau->soa.sa_data)[13]);
+      if (n < 0 || n >= blen) {
 	 Warn("sockaddr_info(): buffer too short");
 	 *buff = '\0';
 	 return buff;
@@ -268,9 +272,9 @@ char *sockaddr_unix_info(const struct sockaddr_un *sa, socklen_t salen, char *bu
 #if WITH_IP4
 /* addr in host byte order! */
 char *inet4addr_info(uint32_t addr, char *buff, size_t blen) {
-   if (snprintf(buff, blen, "%u.%u.%u.%u",
+   if (xio_snprintf(buff, blen, "%u.%u.%u.%u",
 		(unsigned int)(addr >> 24), (unsigned int)((addr >> 16) & 0xff),
-		(unsigned int)((addr >> 8) & 0xff), (unsigned int)(addr & 0xff)) < 0) {
+		(unsigned int)((addr >> 8) & 0xff), (unsigned int)(addr & 0xff)) >= blen) {
       Warn("inet4addr_info(): buffer too short");
       buff[blen-1] = '\0';
    }
@@ -280,12 +284,12 @@ char *inet4addr_info(uint32_t addr, char *buff, size_t blen) {
 
 #if WITH_IP4
 char *sockaddr_inet4_info(const struct sockaddr_in *sa, char *buff, size_t blen) {
-   if (snprintf(buff, blen, "%u.%u.%u.%u:%hu",
+   if (xio_snprintf(buff, blen, "%u.%u.%u.%u:%hu",
 		((unsigned char *)&sa->sin_addr.s_addr)[0],
 		((unsigned char *)&sa->sin_addr.s_addr)[1],
 		((unsigned char *)&sa->sin_addr.s_addr)[2],
 		((unsigned char *)&sa->sin_addr.s_addr)[3],
-		htons(sa->sin_port)) < 0) {
+		htons(sa->sin_port)) >= blen) {
       Warn("sockaddr_inet4_info(): buffer too short");
       buff[blen-1] = '\0';
    }
@@ -301,19 +305,19 @@ const char *inet_ntop(int pf, const void *binaddr,
    switch (pf) {
    case PF_INET:
       if ((retlen =
-	   snprintf(addrtext, textlen, "%u.%u.%u.%u",
+	   xio_snprintf(addrtext, textlen, "%u.%u.%u.%u",
 		    ((unsigned char *)binaddr)[0],
 		    ((unsigned char *)binaddr)[1],
 		    ((unsigned char *)binaddr)[2],
 		    ((unsigned char *)binaddr)[3]))
-	  < 0) {
+	  >= textlen) {
-	 return NULL;	/* errno is valid */
+	 errno = ENOSPC; return NULL;
       }
       break;
 #if WITH_IP6
    case PF_INET6:
       if ((retlen =
-	   snprintf(addrtext, textlen, "%x:%x:%x:%x:%x:%x:%x:%x",
+	   xio_snprintf(addrtext, textlen, "%x:%x:%x:%x:%x:%x:%x:%x",
 		    ntohs(((uint16_t *)binaddr)[0]),
 		    ntohs(((uint16_t *)binaddr)[1]),
 		    ntohs(((uint16_t *)binaddr)[2]),
@@ -323,8 +327,8 @@ const char *inet_ntop(int pf, const void *binaddr,
 		    ntohs(((uint16_t *)binaddr)[6]),
 		    ntohs(((uint16_t *)binaddr)[7])
 		    ))
-	  < 0) {
+	  >= textlen) {
-	 return NULL;	/* errno is valid */
+	 errno = ENOSPC; return NULL;
       }
       break;
 #endif /* WITH_IP6 */
@@ -341,7 +345,7 @@ const char *inet_ntop(int pf, const void *binaddr,
 /* convert the IP6 socket address to human readable form. buff should be at
    least 50 chars long. output includes the port number */
 char *sockaddr_inet6_info(const struct sockaddr_in6 *sa, char *buff, size_t blen) {
-   if (snprintf(buff, blen, "[%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x]:%hu",
+   if (xio_snprintf(buff, blen, "[%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x]:%hu",
 #if HAVE_IP6_SOCKADDR==0
 		(sa->sin6_addr.s6_addr[0]<<8)+
 		sa->sin6_addr.s6_addr[1],
@@ -405,9 +409,8 @@ char *sockaddr_inet6_info(const struct sockaddr_in6 *sa, char *buff, size_t blen
 		ntohs(((unsigned short *)&sa->sin6_addr.__u6_addr.__u6_addr16)[6]),
 		ntohs(((unsigned short *)&sa->sin6_addr.__u6_addr.__u6_addr16)[7]),
 #endif
-		ntohs(sa->sin6_port)) < 0) {
+		ntohs(sa->sin6_port)) >= blen) {
       Warn("sockaddr_inet6_info(): buffer too short");
-      buff[blen-1] = '\0';
    }
    return buff;
 }

utils.c

@@ -1,5 +1,5 @@
 /* source: utils.c */
-/* Copyright Gerhard Rieger 2001-2009 */
+/* Copyright Gerhard Rieger */
 /* Published under the GNU General Public License V.2, see file COPYING */
 
 /* useful additions to C library */
@@ -161,3 +161,22 @@ char *xiosubstr(char *scratch, const char *str, size_t from, size_t len) {
    return scratch0;
 }
       
+
+/* since version 1.7.2.4 socat supports C-99 behaviour of snprintf but still
+   can handle the old glibc case with -1 return on truncation.
+   Do not rely on exact return value in case of truncation
+ */
+int xio_snprintf(char *str, size_t size, const char *format, ...) {
+   va_list ap;
+   int result;
+
+   va_start(ap, format);
+   result = vsnprintf(str, size, format, ap);
+#if ! HAVE_C99_SNPRINTF
+   if (result < 0) {
+      result = size+63;	/* indicate truncation with just some guess */
+   }
+#endif /* !HAVE_C99_SNPRINTF */
+   va_end(ap);
+   return result;
+}

utils.h

@@ -66,4 +66,7 @@ char *sanitize_string(const char *data,	/* input data */
 extern
 char *xiosubstr(char *scratch, const char *str, size_t from, size_t len);
 
+extern
+int xio_snprintf(char *str, size_t size, const char *format, ...);
+
 #endif /* !defined(__utils_h_included) */

xio-ip6.c

@@ -312,7 +312,7 @@ int xiolog_ancillary_ip6(struct cmsghdr *cmsg, int *num,
 /* convert the IP6 socket address to human readable form. buff should be at
    least 50 chars long. output includes the port number */
 static char *inet6addr_info(const struct in6_addr *sa, char *buff, size_t blen) {
-   if (snprintf(buff, blen, "[%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x]",
+   if (xio_snprintf(buff, blen, "[%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x]",
 #if HAVE_IP6_SOCKADDR==0
 		(sa->s6_addr[0]<<8)+sa->s6_addr[1],
 		(sa->s6_addr[2]<<8)+sa->s6_addr[3],
@@ -368,7 +368,7 @@ static char *inet6addr_info(const struct in6_addr *sa, char *buff, size_t blen)
 		ntohs(((unsigned short *)&sa->__u6_addr.__u6_addr16)[6]),
 		ntohs(((unsigned short *)&sa->__u6_addr.__u6_addr16)[7])
 #endif
-		) < 0) {
+		) >= blen) {
       Warn("sockaddr_inet6_info(): buffer too short");
       buff[blen-1] = '\0';
    }