Add APIs to put a "pcap_t" into or out of non-blocking mode, and to get

[libpcap] / pcap.c

diff --git a/pcap.c b/pcap.c
index 712e1430116cef14f7508c1aad44855738227898..1b0e4a4e5f69084e61df736cbf357ac2c91f99fc 100644 (file)
--- a/pcap.c
+++ b/pcap.c
@@ -33,7 +33,7 @@
 
 #ifndef lint
 static const char rcsid[] =
-    "@(#) $Header: /tcpdump/master/libpcap/pcap.c,v 1.36 2000-12-16 10:43:31 guy Exp $ (LBL)";
+    "@(#) $Header: /tcpdump/master/libpcap/pcap.c,v 1.37 2001-12-09 05:10:03 guy Exp $ (LBL)";
 #endif
 
 #ifdef HAVE_CONFIG_H
@@ -46,6 +46,8 @@ static const char rcsid[] =
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
+#include <fcntl.h>
+#include <errno.h>
 
 #ifdef HAVE_OS_PROTO_H
 #include "os-proto.h"
@@ -168,6 +170,65 @@ pcap_geterr(pcap_t *p)
        return (p->errbuf);
 }
 
+/*
+ * NOTE: in the future, these may need to call platform-dependent routines,
+ * e.g. on platforms with memory-mapped packet-capture mechanisms where
+ * "pcap_read()" uses "select()" or "poll()" to wait for packets to arrive.
+ */
+int
+pcap_getnonblock(pcap_t *p, char *errbuf)
+{
+       int fdflags;
+
+       if (p->sf.rfile != NULL) {
+               /*
+                * This is a savefile, not a live capture file, so
+                * never say it's in non-blocking mode.
+                */
+               return (0);
+       }
+       fdflags = fcntl(p->fd, F_GETFL, 0);
+       if (fdflags == -1) {
+               snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "F_GETFL: %s",
+                   pcap_strerror(errno));
+               return (-1);
+       }
+       if (fdflags & O_NONBLOCK)
+               return (1);
+       else
+               return (0);
+}
+
+int
+pcap_setnonblock(pcap_t *p, int nonblock, char *errbuf)
+{
+       int fdflags;
+
+       if (p->sf.rfile != NULL) {
+               /*
+                * This is a savefile, not a live capture file, so
+                * ignore requests to put it in non-blocking mode.
+                */
+               return (0);
+       }
+       fdflags = fcntl(p->fd, F_GETFL, 0);
+       if (fdflags == -1) {
+               snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "F_GETFL: %s",
+                   pcap_strerror(errno));
+               return (-1);
+       }
+       if (nonblock)
+               fdflags |= O_NONBLOCK;
+       else
+               fdflags &= ~O_NONBLOCK;
+       if (fcntl(p->fd, F_SETFL, fdflags) == -1) {
+               snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "F_SETFL: %s",
+                   pcap_strerror(errno));
+               return (-1);
+       }
+       return (fdflags);
+}
+
 /*
  * Not all systems have strerror().
  */