From: Yu Watanabe <watanabe.yu+github@gmail.com>
Date: Wed, 17 Jun 2020 04:54:56 +0000 (+0900)
Subject: network: do not fail to configure non-nl80211 wifi interfaces
X-Git-Tag: v246-rc1~138
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=cc17c4c9a16e4409a566840a68c530165375a221;p=thirdparty%2Fsystemd.git

network: do not fail to configure non-nl80211 wifi interfaces

Also, make wifi_get_interface() and wifi_get_station() initialize
destination buffer when they return a non-negatinve value.

Closes #16160.
---

diff --git a/src/shared/wifi-util.c b/src/shared/wifi-util.c
index 2717db65075..22bb3041fbb 100644
--- a/src/shared/wifi-util.c
+++ b/src/shared/wifi-util.c
@@ -14,6 +14,9 @@ int wifi_get_interface(sd_netlink *genl, int ifindex, enum nl80211_iftype *iftyp
         sd_genl_family family;
         int r;
 
+        assert(genl);
+        assert(ifindex > 0);
+
         r = sd_genl_message_new(genl, SD_GENL_NL80211, NL80211_CMD_GET_INTERFACE, &m);
         if (r < 0)
                 return log_debug_errno(r, "Failed to create generic netlink message: %m");
@@ -23,10 +26,17 @@ int wifi_get_interface(sd_netlink *genl, int ifindex, enum nl80211_iftype *iftyp
                 return log_debug_errno(r, "Could not append NL80211_ATTR_IFINDEX attribute: %m");
 
         r = sd_netlink_call(genl, m, 0, &reply);
+        if (r == -ENODEV) {
+                /* For obsolete WEXT driver. */
+                log_debug_errno(r, "Failed to request information about wifi interface %d. "
+                                "The device doesn't seem to have nl80211 interface. Ignoring.",
+                                ifindex);
+                goto nodata;
+        }
         if (r < 0)
                 return log_debug_errno(r, "Failed to request information about wifi interface %d: %m", ifindex);
         if (!reply)
-                return 0;
+                goto nodata;
 
         r = sd_netlink_message_get_errno(reply);
         if (r < 0)
@@ -37,7 +47,7 @@ int wifi_get_interface(sd_netlink *genl, int ifindex, enum nl80211_iftype *iftyp
                 return log_debug_errno(r, "Failed to determine genl family: %m");
         if (family != SD_GENL_NL80211) {
                 log_debug("Received message of unexpected genl family %u, ignoring.", family);
-                return 0;
+                goto nodata;
         }
 
         if (iftype) {
@@ -51,11 +61,20 @@ int wifi_get_interface(sd_netlink *genl, int ifindex, enum nl80211_iftype *iftyp
 
         if (ssid) {
                 r = sd_netlink_message_read_string_strdup(reply, NL80211_ATTR_SSID, ssid);
-                if (r < 0 && r != -ENODATA)
+                if (r == -ENODATA)
+                        goto nodata;
+                if (r < 0)
                         return log_debug_errno(r, "Failed to get NL80211_ATTR_SSID attribute: %m");
         }
 
-        return r == -ENODATA ? 0 : 1;
+        return 1;
+
+nodata:
+        if (iftype)
+                *iftype = 0;
+        if (ssid)
+                *ssid = NULL;
+        return 0;
 }
 
 int wifi_get_station(sd_netlink *genl, int ifindex, struct ether_addr *bssid) {
@@ -63,6 +82,10 @@ int wifi_get_station(sd_netlink *genl, int ifindex, struct ether_addr *bssid) {
         sd_genl_family family;
         int r;
 
+        assert(genl);
+        assert(ifindex > 0);
+        assert(bssid);
+
         r = sd_genl_message_new(genl, SD_GENL_NL80211, NL80211_CMD_GET_STATION, &m);
         if (r < 0)
                 return log_debug_errno(r, "Failed to create generic netlink message: %m");
@@ -79,7 +102,7 @@ int wifi_get_station(sd_netlink *genl, int ifindex, struct ether_addr *bssid) {
         if (r < 0)
                 return log_debug_errno(r, "Failed to request information about wifi station: %m");
         if (!reply)
-                return 0;
+                goto nodata;
 
         r = sd_netlink_message_get_errno(reply);
         if (r < 0)
@@ -90,12 +113,18 @@ int wifi_get_station(sd_netlink *genl, int ifindex, struct ether_addr *bssid) {
                 return log_debug_errno(r, "Failed to determine genl family: %m");
         if (family != SD_GENL_NL80211) {
                 log_debug("Received message of unexpected genl family %u, ignoring.", family);
-                return 0;
+                goto nodata;
         }
 
         r = sd_netlink_message_read_ether_addr(reply, NL80211_ATTR_MAC, bssid);
-        if (r < 0 && r != -ENODATA)
+        if (r == -ENODATA)
+                goto nodata;
+        if (r < 0)
                 return log_debug_errno(r, "Failed to get NL80211_ATTR_MAC attribute: %m");
 
-        return r == -ENODATA ? 0 : 1;
+        return 1;
+
+nodata:
+        *bssid = (struct ether_addr) {};
+        return 0;
 }