Libnl 2.x returns its own error codes, not errnos; handle that.

While we're at it, don't special-case ENFILE for "delete monitor device"
operations; that's not like "add monitor device", where we want to drive
on if a device with that name already exists.

diff --git a/pcap-linux.c b/pcap-linux.c
index deabbc4a986a2232d9515207e259c7f6d70ce47d..5d291e955aa11356434fafc9d73e8ab2a8984d56 100644 (file)
--- a/pcap-linux.c
+++ b/pcap-linux.c
@@ -527,7 +527,9 @@ get_mac80211_phydev(pcap_t *handle, const char *device, char *phydev_path,
        return 1;
 }
 
-#ifndef HAVE_LIBNL_2_x
+#ifdef HAVE_LIBNL_2_x
+#define get_nl_errmsg  nl_geterror
+#else
 /* libnl 2.x compatibility code */
 
 #define nl_sock nl_handle
@@ -544,6 +546,8 @@ nl_socket_free(struct nl_handle *h)
        nl_handle_destroy(h);
 }
 
+#define get_nl_errmsg  strerror
+
 static inline int
 __genl_ctrl_alloc_cache(struct nl_handle *h, struct nl_cache **cache)
 {
@@ -584,7 +588,7 @@ nl80211_init(pcap_t *handle, struct nl80211_state *state, const char *device)
        if (err < 0) {
                snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
                    "%s: failed to allocate generic netlink cache: %s",
-                   device, strerror(-err));
+                   device, get_nl_errmsg(-err));
                goto out_handle_destroy;
        }
 
@@ -639,10 +643,17 @@ add_mon_if(pcap_t *handle, int sock_fd, struct nl80211_state *state,
 
        err = nl_send_auto_complete(state->nl_sock, msg);
        if (err < 0) {
+#ifdef HAVE_LIBNL_2_x
+               if (err == -NLE_FAILURE) {
+#else
                if (err == -ENFILE) {
+#endif
                        /*
                         * Device not available; our caller should just
-                        * keep trying.
+                        * keep trying.  (libnl 2.x maps ENFILE to
+                        * NLE_FAILURE; it can also map other errors
+                        * to that, but there's not much we can do
+                        * about that.)
                         */
                        nlmsg_free(msg);
                        return 0;
@@ -653,17 +664,24 @@ add_mon_if(pcap_t *handle, int sock_fd, struct nl80211_state *state,
                         */
                        snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
                            "%s: nl_send_auto_complete failed adding %s interface: %s",
-                           device, mondevice, strerror(-err));
+                           device, mondevice, get_nl_errmsg(-err));
                        nlmsg_free(msg);
                        return PCAP_ERROR;
                }
        }
        err = nl_wait_for_ack(state->nl_sock);
        if (err < 0) {
+#ifdef HAVE_LIBNL_2_x
+               if (err == -NLE_FAILURE) {
+#else
                if (err == -ENFILE) {
+#endif
                        /*
                         * Device not available; our caller should just
-                        * keep trying.
+                        * keep trying.  (libnl 2.x maps ENFILE to
+                        * NLE_FAILURE; it can also map other errors
+                        * to that, but there's not much we can do
+                        * about that.)
                         */
                        nlmsg_free(msg);
                        return 0;
@@ -674,7 +692,7 @@ add_mon_if(pcap_t *handle, int sock_fd, struct nl80211_state *state,
                         */
                        snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
                            "%s: nl_wait_for_ack failed adding %s interface: %s",
-                           device, mondevice, strerror(-err));
+                           device, mondevice, get_nl_errmsg(-err));
                        nlmsg_free(msg);
                        return PCAP_ERROR;
                }
@@ -719,45 +737,19 @@ del_mon_if(pcap_t *handle, int sock_fd, struct nl80211_state *state,
 
        err = nl_send_auto_complete(state->nl_sock, msg);
        if (err < 0) {
-               if (err == -ENFILE) {
-                       /*
-                        * Device not available; our caller should just
-                        * keep trying.
-                        */
-                       nlmsg_free(msg);
-                       return 0;
-               } else {
-                       /*
-                        * Real failure, not just "that device is not
-                        * available.
-                        */
-                       snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
-                           "%s: nl_send_auto_complete failed deleting %s interface: %s",
-                           device, mondevice, strerror(-err));
-                       nlmsg_free(msg);
-                       return PCAP_ERROR;
-               }
+               snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
+                   "%s: nl_send_auto_complete failed deleting %s interface: %s",
+                   device, mondevice, get_nl_errmsg(-err));
+               nlmsg_free(msg);
+               return PCAP_ERROR;
        }
        err = nl_wait_for_ack(state->nl_sock);
        if (err < 0) {
-               if (err == -ENFILE) {
-                       /*
-                        * Device not available; our caller should just
-                        * keep trying.
-                        */
-                       nlmsg_free(msg);
-                       return 0;
-               } else {
-                       /*
-                        * Real failure, not just "that device is not
-                        * available.
-                        */
-                       snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
-                           "%s: nl_wait_for_ack failed adding %s interface: %s",
-                           device, mondevice, strerror(-err));
-                       nlmsg_free(msg);
-                       return PCAP_ERROR;
-               }
+               snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
+                   "%s: nl_wait_for_ack failed adding %s interface: %s",
+                   device, mondevice, get_nl_errmsg(-err));
+               nlmsg_free(msg);
+               return PCAP_ERROR;
        }
 
        /*