ioops: misc: add dup{,2}_or_die to ioops

Bail out if it should ever fail. Detected by coverty in the
translate_pcap_to_txf() path.

Signed-off-by: Daniel Borkmann <dborkman@redhat.com>

6 files changed, 26 insertions, 17 deletions

diff --git a/geoip.c b/geoip.c
index b403ad1..d027e14 100644
--- a/geoip.c
+++ b/geoip.c
@@ -348,10 +348,10 @@ static int fdout, fderr;
 static void geoip_open_prepare(void)
 {
 	fflush(stdout);
-	fdout = dup(1);
+	fdout = dup_or_die(1);
 
 	fflush(stderr);
-	fderr = dup(2);
+	fderr = dup_or_die(2);
 
 	close(1);
 	close(2);
@@ -359,8 +359,8 @@ static void geoip_open_prepare(void)
 
 static void geoip_open_restore(void)
 {
-	dup2(fdout, 1);
-	dup2(fderr, 2);
+	dup2_or_die(fdout, 1);
+	dup2_or_die(fderr, 2);
 
 	close(fdout);
 	close(fderr);
diff --git a/ioops.c b/ioops.c
index 7cec2fd..4ac0f3a 100644
--- a/ioops.c
+++ b/ioops.c
@@ -12,6 +12,7 @@
 #include "dev.h"
 #include "ioops.h"
 #include "str.h"
+#include "built_in.h"
 
 int open_or_die(const char *file, int flags)
 {
@@ -30,6 +31,21 @@ int open_or_die_m(const char *file, int flags, mode_t mode)
 	return ret;
 }
 
+int dup_or_die(int oldfd)
+{
+	int newfd = dup(oldfd);
+	if (unlikely(newfd < 0))
+		panic("Cannot dup old file descriptor!\n");
+	return newfd;
+}
+
+void dup2_or_die(int oldfd, int newfd)
+{
+	int ret = dup2(oldfd, newfd);
+	if (unlikely(ret < 0))
+		panic("Cannot dup2 old/new file descriptor!\n");
+}
+
 void create_or_die(const char *file, mode_t mode)
 {
 	int fd = open_or_die_m(file, O_WRONLY | O_CREAT, mode);
diff --git a/ioops.h b/ioops.h
index 6de6c62..8e12448 100644
--- a/ioops.h
+++ b/ioops.h
@@ -5,6 +5,8 @@
 
 extern int open_or_die(const char *file, int flags);
 extern int open_or_die_m(const char *file, int flags, mode_t mode);
+extern int dup_or_die(int oldfd);
+extern void dup2_or_die(int oldfd, int newfd);
 extern void create_or_die(const char *file, mode_t mode);
 extern int tun_open_or_die(char *name, int type);
 extern void pipe_or_die(int pipefd[2], int flags);
diff --git a/netsniff-ng.c b/netsniff-ng.c
index 14ce8f2..2738b9a 100644
--- a/netsniff-ng.c
+++ b/netsniff-ng.c
@@ -184,7 +184,7 @@ static void pcap_to_xmit(struct ctx *ctx)
 	tx_sock = pf_socket();
 
 	if (!strncmp("-", ctx->device_in, strlen("-"))) {
-		fd = dup(fileno(stdin));
+		fd = dup_or_die(fileno(stdin));
 		close(fileno(stdin));
 		if (ctx->pcap == PCAP_OPS_MM)
 			ctx->pcap = PCAP_OPS_SG;
@@ -544,7 +544,7 @@ static void read_pcap(struct ctx *ctx)
 	bug_on(!__pcap_io);
 
 	if (!strncmp("-", ctx->device_in, strlen("-"))) {
-		fd = dup(fileno(stdin));
+		fd = dup_or_die(fileno(stdin));
 		close(fileno(stdin));
 		if (ctx->pcap == PCAP_OPS_MM)
 			ctx->pcap = PCAP_OPS_SG;
@@ -579,7 +579,7 @@ static void read_pcap(struct ctx *ctx)
 
 	if (ctx->device_out) {
 		if (!strncmp("-", ctx->device_out, strlen("-"))) {
-			fdo = dup(fileno(stdout));
+			fdo = dup_or_die(fileno(stdout));
 			close(fileno(stdout));
 		} else {
 			fdo = open_or_die_m(ctx->device_out, O_RDWR | O_CREAT |
@@ -769,7 +769,7 @@ static int begin_single_pcap_file(struct ctx *ctx)
 	bug_on(!__pcap_io);
 
 	if (!strncmp("-", ctx->device_out, strlen("-"))) {
-		fd = dup(fileno(stdout));
+		fd = dup_or_die(fileno(stdout));
 		close(fileno(stdout));
 		if (ctx->pcap == PCAP_OPS_MM)
 			ctx->pcap = PCAP_OPS_SG;
diff --git a/xmalloc.c b/xmalloc.c
index d5805b8..02d6ce4 100644
--- a/xmalloc.c
+++ b/xmalloc.c
@@ -141,11 +141,3 @@ char *xstrndup(const char *str, size_t size)
 
 	return cp;
 }
-
-int xdup(int fd)
-{
-	int ret = dup(fd);
-	if (unlikely(ret < 0))
-		panic("xdup: dup failed\n");
-	return ret;
-}
diff --git a/xmalloc.h b/xmalloc.h
index 21ce84d..e1e4f8f 100644
--- a/xmalloc.h
+++ b/xmalloc.h
@@ -16,7 +16,6 @@ extern void *xrealloc(void *ptr, size_t nmemb, size_t size) __hidden;
 extern void xfree_func(void *ptr) __hidden;
 extern char *xstrdup(const char *str) __hidden;
 extern char *xstrndup(const char *str, size_t size) __hidden;
-extern int xdup(int fd) __hidden;
 
 static inline void __xfree(void *ptr)
 {