X-Git-Url: https://git.tcpdump.org/libpcap/blobdiff_plain/51288332aea19566627aed7a5018cd35367df10d..c909e8a31ffcbb7f1a41bb801392e14f5d20e1fc:/pcap-netmap.c

diff --git a/pcap-netmap.c b/pcap-netmap.c
index 3c9de68a..ee8d8b3a 100644
--- a/pcap-netmap.c
+++ b/pcap-netmap.c
@@ -25,7 +25,7 @@
  */
 
 #ifdef HAVE_CONFIG_H
-#include "config.h"
+#include <config.h>
 #endif
 
 #include <poll.h>
@@ -188,13 +188,14 @@ static int
 pcap_netmap_activate(pcap_t *p)
 {
 	struct pcap_netmap *pn = p->priv;
-	struct nm_desc *d = nm_open(p->opt.device, NULL, 0, NULL);
+	struct nm_desc *d;
 	uint32_t if_flags = 0;
 
+	d = nm_open(p->opt.device, NULL, 0, NULL);
 	if (d == NULL) {
-		snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
-			"netmap open: cannot access %s: %s\n",
-			p->opt.device, pcap_strerror(errno));
+		pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
+		    errno, "netmap open: cannot access %s",
+		    p->opt.device);
 		pcap_cleanup_live_common(p);
 		return (PCAP_ERROR);
 	}
@@ -204,6 +205,18 @@ pcap_netmap_activate(pcap_t *p)
 		d->first_rx_ring, d->last_rx_ring);
 	pn->d = d;
 	p->fd = d->fd;
+
+	/*
+	 * Turn a negative snapshot value (invalid), a snapshot value of
+	 * 0 (unspecified), or a value bigger than the normal maximum
+	 * value, into the maximum allowed value.
+	 *
+	 * If some application really *needs* a bigger snapshot
+	 * length, we should just increase MAXIMUM_SNAPLEN.
+	 */
+	if (p->snapshot <= 0 || p->snapshot > MAXIMUM_SNAPLEN)
+		p->snapshot = MAXIMUM_SNAPLEN;
+
 	if (p->opt.promisc && !(d->req.nr_ringid & NETMAP_SW_RING)) {
 		pcap_netmap_ioctl(p, SIOCGIFFLAGS, &if_flags); /* fetch flags */
 		if (!(if_flags & IFF_PPROMISC)) {
@@ -244,11 +257,12 @@ pcap_netmap_create(const char *device, char *ebuf, int *is_ours)
 }
 
 /*
- * XXX - is there a way to enumerate the netmap devices?
+ * The "device name" for netmap devices isn't a name for a device, it's
+ * an expression that indicates how the device should be set up, so
+ * there's no way to enumerate them.
  */
 int
-pcap_netmap_findalldevs(pcap_if_list_t *devlistp, char *err_str)
+pcap_netmap_findalldevs(pcap_if_list_t *devlistp _U_, char *err_str _U_)
 {
 	return 0;
 }
-