Don't try to open non-cloning devices if we have a cloning device.

diff --git a/pcap-bpf.c b/pcap-bpf.c
index e821ff05105c73de22236327d517f41ba9341de7..78813a5dca5399d02b5bf2975cb9f77760b6f36f 100644 (file)
--- a/pcap-bpf.c
+++ b/pcap-bpf.c
@@ -476,7 +476,7 @@ pcap_create_interface(const char *device _U_, char *ebuf)
 static int
 bpf_open(char *errbuf)
 {
 static int
 bpf_open(char *errbuf)
 {

-       int fd;
+       int fd = -1;

        static const char cloning_device[] = "/dev/bpf";
        int n = 0;
        char device[sizeof "/dev/bpf0000000000"];
        static const char cloning_device[] = "/dev/bpf";
        int n = 0;
        char device[sizeof "/dev/bpf0000000000"];


@@ -508,37 +508,40 @@ bpf_open(char *errbuf)
                        else
                                fd = PCAP_ERROR;
                        pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE,
                        else
                                fd = PCAP_ERROR;
                        pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE,

-                         "(cannot open device) %s: %s", device,
+                         "(cannot open device) %s: %s", cloning_device,

                          pcap_strerror(errno));
                        return (fd);
                }
                no_cloning_bpf = 1;
        }
 
                          pcap_strerror(errno));
                        return (fd);
                }
                no_cloning_bpf = 1;
        }
 

-       /*
-        * Go through all the /dev/bpfN minors and find one that isn't
-        * in use.
-        */
-       do {
-               (void)pcap_snprintf(device, sizeof(device), "/dev/bpf%d", n++);
+       if (no_cloning_bpf) {

                /*
                /*

-                * Initially try a read/write open (to allow the inject
-                * method to work).  If that fails due to permission
-                * issues, fall back to read-only.  This allows a
-                * non-root user to be granted specific access to pcap
-                * capabilities via file permissions.
-                *
-                * XXX - we should have an API that has a flag that
-                * controls whether to open read-only or read-write,
-                * so that denial of permission to send (or inability
-                * to send, if sending packets isn't supported on
-                * the device in question) can be indicated at open
-                * time.
+                * We don't have /dev/bpf.
+                * Go through all the /dev/bpfN minors and find one
+                * that isn't in use.

                 */
                 */

-               fd = open(device, O_RDWR);
-               if (fd == -1 && errno == EACCES)
-                       fd = open(device, O_RDONLY);
-       } while (fd < 0 && errno == EBUSY);
+               do {
+                       (void)pcap_snprintf(device, sizeof(device), "/dev/bpf%d", n++);
+                       /*
+                        * Initially try a read/write open (to allow the inject
+                        * method to work).  If that fails due to permission
+                        * issues, fall back to read-only.  This allows a
+                        * non-root user to be granted specific access to pcap
+                        * capabilities via file permissions.
+                        *
+                        * XXX - we should have an API that has a flag that
+                        * controls whether to open read-only or read-write,
+                        * so that denial of permission to send (or inability
+                        * to send, if sending packets isn't supported on
+                        * the device in question) can be indicated at open
+                        * time.
+                        */
+                       fd = open(device, O_RDWR);
+                       if (fd == -1 && errno == EACCES)
+                               fd = open(device, O_RDONLY);
+               } while (fd < 0 && errno == EBUSY);
+       }

 
        /*
         * XXX better message for all minors used
 
        /*
         * XXX better message for all minors used