return (n);
}
+/*
+ * Look for a given device in the specified list of devices.
+ *
+ * If we find it, return 0 and set *curdev_ret to point to it.
+ *
+ * If we don't find it, check whether we can open it:
+ *
+ * If that fails with PCAP_ERROR_NO_SUCH_DEVICE or
+ * PCAP_ERROR_IFACE_NOT_UP, don't attempt to add an entry for
+ * it, as that probably means it exists but doesn't support
+ * packet capture.
+ *
+ * Otherwise, attempt to add an entry for it, with the specified
+ * ifnet flags and description, and, if that succeeds, return 0
+ * and set *curdev_ret to point to the new entry, otherwise
+ * return PCAP_ERROR and set errbuf to an error message.
+ */
int
add_or_find_if(pcap_if_t **curdev_ret, pcap_if_t **alldevs, const char *name,
u_int flags, const char *description, char *errbuf)
pcap_if_t *curdev, *prevdev, *nextdev;
u_int this_figure_of_merit, nextdev_figure_of_merit;
char open_errbuf[PCAP_ERRBUF_SIZE];
+ int ret;
/*
* Is there already an entry in the list for this interface?
}
strcpy(en_name, "en");
strcat(en_name, name + 3);
- p = pcap_open_live(en_name, 68, 0, 0, open_errbuf);
+ p = pcap_create(en_name, open_errbuf);
free(en_name);
} else
#endif /* __APPLE */
- p = pcap_open_live(name, 68, 0, 0, open_errbuf);
+ p = pcap_create(name, open_errbuf);
if (p == NULL) {
/*
- * No. Don't bother including it.
- * Don't treat this as an error, though.
+ * The attempt to create the pcap_t failed;
+ * that's probably an indication that we're
+ * out of memory.
+ *
+ * Don't bother including this interface,
+ * but don't treat it as an error.
*/
*curdev_ret = NULL;
return (0);
}
+ /* Small snaplen, so we don't try to allocate much memory. */
+ pcap_set_snaplen(p, 68);
+ ret = pcap_activate(p);
pcap_close(p);
+ switch (ret) {
+
+ case PCAP_ERROR_NO_SUCH_DEVICE:
+ case PCAP_ERROR_IFACE_NOT_UP:
+ /*
+ * We expect these two errors - they're the
+ * reason we try to open the device.
+ *
+ * PCAP_ERROR_NO_SUCH_DEVICE typically means
+ * "there's no such device *known to the
+ * OS's capture mechanism*", so, even though
+ * it might be a valid network interface, you
+ * can't capture on it (e.g., the loopback
+ * device in Solaris up to Solaris 10, or
+ * the vmnet devices in OS X with VMware
+ * Fusion). We don't include those devices
+ * in our list of devices, as there's no
+ * point in doing so - they're not available
+ * for capture.
+ *
+ * PCAP_ERROR_IFACE_NOT_UP means that the
+ * OS's capture mechanism doesn't work on
+ * interfaces not marked as up; some capture
+ * mechanisms *do* support that, so we no
+ * longer reject those interfaces out of hand,
+ * but we *do* want to reject them if they
+ * can't be opened for capture.
+ */
+ *curdev_ret = NULL;
+ return (0);
+ }
/*
- * Yes, we can open it.
+ * Yes, we can open it, or we can't, for some other
+ * reason.
+ *
+ * If we can open it, we want to offer it for
+ * capture, as you can capture on it. If we can't,
+ * we want to offer it for capture, so that, if
+ * the user tries to capture on it, they'll get
+ * an error and they'll know why they can't
+ * capture on it (e.g., insufficient permissions)
+ * or they'll report it as a problem (and then
+ * have the error message to provide as information).
+ *
* Allocate a new entry.
*/
curdev = malloc(sizeof(pcap_if_t));
#endif /* SIOCGIFDESCR */
}
+/*
+ * Try to get a description for a given device, and then look for that
+ * device in the specified list of devices.
+ *
+ * If we find it, add the specified address to it and return 0.
+ *
+ * If we don't find it, check whether we can open it:
+ *
+ * If that fails with PCAP_ERROR_NO_SUCH_DEVICE or
+ * PCAP_ERROR_IFACE_NOT_UP, don't attempt to add an entry for
+ * it, as that probably means it exists but doesn't support
+ * packet capture.
+ *
+ * Otherwise, attempt to add an entry for it, with the specified
+ * ifnet flags and description, and, if that succeeds, add the
+ * specified address to it, set *curdev_ret to point to the new
+ * entry, and return 0, otherwise return PCAP_ERROR and set errbuf
+ * to an error message.
+ */
int
add_addr_to_iflist(pcap_if_t **alldevs, const char *name, u_int flags,
struct sockaddr *addr, size_t addr_size,
struct sockaddr *dstaddr, size_t dstaddr_size,
char *errbuf)
{
- pcap_if_t *curdev;
char *description;
+ pcap_if_t *curdev;
description = get_if_description(name);
if (add_or_find_if(&curdev, alldevs, name, flags, description,
return (0);
}
+/*
+ * Look for a given device in the specified list of devices.
+ *
+ * If we find it, return 0.
+ *
+ * If we don't find it, check whether we can open it:
+ *
+ * If that fails with PCAP_ERROR_NO_SUCH_DEVICE or
+ * PCAP_ERROR_IFACE_NOT_UP, don't attempt to add an entry for
+ * it, as that probably means it exists but doesn't support
+ * packet capture.
+ *
+ * Otherwise, attempt to add an entry for it, with the specified
+ * ifnet flags and description, and, if that succeeds, return 0
+ * and set *curdev_ret to point to the new entry, otherwise
+ * return PCAP_ERROR and set errbuf to an error message.
+ */
int
pcap_add_if(pcap_if_t **devlist, const char *name, u_int flags,
const char *description, char *errbuf)
projects / libpcap / blobdiff