]> The Tcpdump Group git mirrors - libpcap/blobdiff - pcap-snit.c
Update config.{guess,sub}, timestamps 2023-01-01,2023-01-21
[libpcap] / pcap-snit.c
index 77cb07f9c82b8f0c044a3903c40e44e5667bd2d2..3f4e69d7186329c8018d504652e667b1ee5c27e6 100644 (file)
@@ -53,7 +53,6 @@
 #include <netinet/tcp.h>
 #include <netinet/tcpip.h>
 
-#include <ctype.h>
 #include <errno.h>
 #include <stdio.h>
 #include <string.h>
@@ -140,6 +139,9 @@ pcap_read_snit(pcap_t *p, int cnt, pcap_handler callback, u_char *user)
 
        /*
         * loop through each snapshot in the chunk
+        *
+        * This assumes that a single buffer of packets will have
+        * <= INT_MAX packets, so the packet count doesn't overflow.
         */
        n = 0;
        ep = bp + cc;
@@ -332,12 +334,16 @@ pcap_activate_snit(pcap_t *p)
        if (fd < 0 && errno == EACCES)
                p->fd = fd = open(dev, O_RDONLY);
        if (fd < 0) {
-               if (errno == EACCES)
+               if (errno == EACCES) {
                        err = PCAP_ERROR_PERM_DENIED;
-               else
+                       snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
+                           "Attempt to open %s failed with EACCES - root privileges may be required",
+                           dev);
+               } else {
                        err = PCAP_ERROR;
-               pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
-                   errno, "%s", dev);
+                       pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
+                           errno, "%s", dev);
+               }
                goto bad;
        }
 
@@ -460,7 +466,7 @@ pcap_create_interface(const char *device _U_, char *ebuf)
 {
        pcap_t *p;
 
-       p = pcap_create_common(ebuf, sizeof (struct pcap_snit));
+       p = PCAP_CREATE_COMMON(ebuf, struct pcap_snit);
        if (p == NULL)
                return (NULL);