Return errors from pcap_dump and pcap_dump_close

Author: rigtorp

CHANGES

@@ -8,6 +8,8 @@ DayOfTheWeek, Month DD, YYYY / The Tcpdump Group
       Finalize moving of bpf_filter.c. (GH #1166)
       Address a few compiler warnings on Haiku.
       struct pcap: Update buffer type from "void *" to "u_char *".
+      Add pcap_dump1 and pcap_dump_close1 functions that propagates
+      write errors to the caller.
     Link-layer types:
       Add LINKTYPE_ETW/DLT_ETW.
       Add LINKTYPE_NETANALYZER_NG/DLT_NETANALYZER_NG (pull request

CMakeLists.txt

@@ -3555,7 +3555,9 @@ if(NOT MSVC)
         install(FILES ${MAN3PCAP} DESTINATION ${CMAKE_INSTALL_MANDIR}/man3)
         install_manpage_symlink(pcap_datalink_val_to_name.3pcap pcap_datalink_val_to_description.3pcap ${CMAKE_INSTALL_MANDIR}/man3)
         install_manpage_symlink(pcap_datalink_val_to_name.3pcap pcap_datalink_val_to_description_or_dlt.3pcap ${CMAKE_INSTALL_MANDIR}/man3)
+        install_manpage_symlink(pcap_dump_close.3pcap pcap_dump_close1.3pcap ${CMAKE_INSTALL_MANDIR}/man3)
         install_manpage_symlink(pcap_dump_open.3pcap pcap_dump_fopen.3pcap ${CMAKE_INSTALL_MANDIR}/man3)
+        install_manpage_symlink(pcap_dump.3pcap pcap_dump1.3pcap ${CMAKE_INSTALL_MANDIR}/man3)
         install_manpage_symlink(pcap_findalldevs.3pcap pcap_freealldevs.3pcap ${CMAKE_INSTALL_MANDIR}/man3)
         install_manpage_symlink(pcap_geterr.3pcap pcap_perror.3pcap ${CMAKE_INSTALL_MANDIR}/man3)
         install_manpage_symlink(pcap_inject.3pcap pcap_sendpacket.3pcap ${CMAKE_INSTALL_MANDIR}/man3)

Makefile.in

@@ -627,8 +627,12 @@ install: install-shared install-archive libpcap.pc pcap-config @INSTALL_RPCAPD@
 	rm -f pcap_datalink_val_to_description_or_dlt.3pcap && \
 	$(LN_S) pcap_datalink_val_to_name.3pcap \
 		 pcap_datalink_val_to_description_or_dlt.3pcap && \
+	rm -f pcap_dump_close1.3pcap && \
+	$(LN_S) pcap_dump_close.3pcap pcap_dump_close1.3pcap && \
 	rm -f pcap_dump_fopen.3pcap && \
 	$(LN_S) pcap_dump_open.3pcap pcap_dump_fopen.3pcap && \
+	rm -f pcap_dump1.3pcap && \
+	$(LN_S) pcap_dump.3pcap pcap_dump1.3pcap && \
 	rm -f pcap_freealldevs.3pcap && \
 	$(LN_S) pcap_findalldevs.3pcap pcap_freealldevs.3pcap && \
 	rm -f pcap_perror.3pcap && \

pcap/pcap.h

@@ -788,9 +788,15 @@ PCAP_API int	pcap_dump_flush(pcap_dumper_t *);
 PCAP_AVAILABLE_0_4
 PCAP_API void	pcap_dump_close(pcap_dumper_t *);
 
+PCAP_AVAILABLE_1_11
+PCAP_API int	pcap_dump_close1(pcap_dumper_t *);
+
 PCAP_AVAILABLE_0_4
 PCAP_API void	pcap_dump(u_char *, const struct pcap_pkthdr *, const u_char *);
 
+PCAP_AVAILABLE_1_11
+PCAP_API int	pcap_dump1(u_char *, const struct pcap_pkthdr *, const u_char *);
+
 PCAP_AVAILABLE_0_7
 PCAP_API int	pcap_findalldevs(pcap_if_t **, char *);
 

pcap_dump.3pcap

@@ -19,7 +19,7 @@
 .\"
 .TH PCAP_DUMP 3PCAP "8 March 2015"
 .SH NAME
-pcap_dump \- write a packet to a capture file
+pcap_dump, pcap_dump1 \- write a packet to a capture file
 .SH SYNOPSIS
 .nf
 .ft B
@@ -29,6 +29,9 @@ pcap_dump \- write a packet to a capture file
 .ft B
 void pcap_dump(u_char *user, struct pcap_pkthdr *h,
     u_char *sp);
+.ti +8
+int pcap_dump1(u_char *user, struct pcap_pkthdr *h,
+    u_char *sp);
 .ft
 .fi
 .SH DESCRIPTION
@@ -45,5 +48,11 @@ parameter is of type
 .B pcap_dumper_t
 as returned by
 .BR pcap_dump_open ().
+.SH RETURN VALUE
+Returns
+.B 0
+on success and
+.B PCAP_ERROR
+on failure.
 .SH SEE ALSO
 .BR pcap (3PCAP)

pcap_dump_close.3pcap

@@ -19,7 +19,7 @@
 .\"
 .TH PCAP_DUMP_CLOSE 3PCAP "3 January 2014"
 .SH NAME
-pcap_dump_close \- close a savefile being written to
+pcap_dump_close, pcap_dump_close1 \- close a savefile being written to
 .SH SYNOPSIS
 .nf
 .ft B
@@ -28,11 +28,18 @@ pcap_dump_close \- close a savefile being written to
 .LP
 .ft B
 void pcap_dump_close(pcap_dumper_t *p);
+int pcap_dump_close1(pcap_dumper_t *p);
 .ft
 .fi
 .SH DESCRIPTION
 .BR pcap_dump_close ()
 closes the ``savefile.''
+.SH RETURN VALUE
+Returns
+.B 0
+on success and
+.B PCAP_ERROR
+on failure.
 .SH SEE ALSO
 .BR pcap (3PCAP),
 .BR pcap_dump_open (3PCAP),

sf-pcap.c

@@ -744,6 +744,12 @@ sf_write_header(pcap_t *p, FILE *fp, int linktype, int snaplen)
  */
 void
 pcap_dump(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
+{
+	(void)pcap_dump1(user, h, sp);
+}
+
+int
+pcap_dump1(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
 {
 	register FILE *f;
 	struct pcap_sf_pkthdr sf_hdr;
@@ -766,7 +772,7 @@ pcap_dump(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
 	 * http://pubs.opengroup.org/onlinepubs/009695399/functions/fwrite.html
 	 */
 	if (ferror(f))
-		return;
+		return (-1);
 	/*
 	 * Better not try writing pcap files after
 	 * 2038-01-19 03:14:07 UTC; switch to pcapng.
@@ -783,9 +789,14 @@ pcap_dump(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
 	 * way to set ferror() to prevent future writes from being
 	 * attempted, but it is better than nothing.
 	 */
-	if (fwrite(&sf_hdr, sizeof(sf_hdr), 1, f) == 1) {
-		(void)fwrite(sp, h->caplen, 1, f);
+	if (fwrite(&sf_hdr, 1, sizeof(sf_hdr), f) != sizeof(sf_hdr)) {
+		return (-1);
+	}
+	if (fwrite(sp, 1, h->caplen, f) != h->caplen) {
+		return (-1);
 	}
+
+	return (0);
 }
 
 static pcap_dumper_t *
@@ -1181,11 +1192,14 @@ pcap_dump_flush(pcap_dumper_t *p)
 void
 pcap_dump_close(pcap_dumper_t *p)
 {
+	(void)pcap_dump_close1(p);
+}
 
-#ifdef notyet
-	if (ferror((FILE *)p))
-		return-an-error;
-	/* XXX should check return from fclose() too */
-#endif
-	(void)fclose((FILE *)p);
+int
+pcap_dump_close1(pcap_dumper_t *p)
+{
+	if (fclose((FILE *)p) == EOF) {
+		return (-1);
+	}
+	return (0);
 }