netdev-linux: Drop support for pre-2.6.19 kernels.

The OVS kernel module requires 2.6.32 or later, so there's no reason for
userspace to support older kernels.  This commit removes the special
fallback code for retrieving Linux netdev stats in pre-2.6.19 kernels,
which should no longer be useful.

Signed-off-by: Ben Pfaff <blp@nicira.com>

diff --git a/lib/netdev-linux.c b/lib/netdev-linux.c
index 9bdbbdf..1fe662a 100644 (file)
--- a/lib/netdev-linux.c
+++ b/lib/netdev-linux.c
@@ -427,8 +427,7 @@ static int do_set_addr(struct netdev *netdev,
                        struct in_addr addr);
 static int get_etheraddr(const char *netdev_name, uint8_t ea[ETH_ADDR_LEN]);
 static int set_etheraddr(const char *netdev_name, const uint8_t[ETH_ADDR_LEN]);
-static int get_stats_via_netlink(int ifindex, struct netdev_stats *stats);
-static int get_stats_via_proc(const char *netdev_name, struct netdev_stats *stats);
+static int get_stats_via_netlink(const struct netdev *, struct netdev_stats *);
 static int af_packet_sock(void);
 static bool netdev_linux_miimon_enabled(void);
 static void netdev_linux_miimon_run(void);
@@ -1312,34 +1311,6 @@ netdev_linux_miimon_wait(void)
     shash_destroy(&device_shash);
 }
 
-/* Check whether we can we use RTM_GETLINK to get network device statistics.
- * In pre-2.6.19 kernels, this was only available if wireless extensions were
- * enabled. */
-static bool
-check_for_working_netlink_stats(void)
-{
-    /* Decide on the netdev_get_stats() implementation to use.  Netlink is
-     * preferable, so if that works, we'll use it. */
-    int ifindex = do_get_ifindex("lo");
-    if (ifindex < 0) {
-        VLOG_WARN("failed to get ifindex for lo, "
-                  "obtaining netdev stats from proc");
-        return false;
-    } else {
-        struct netdev_stats stats;
-        int error = get_stats_via_netlink(ifindex, &stats);
-        if (!error) {
-            VLOG_DBG("obtaining netdev stats via rtnetlink");
-            return true;
-        } else {
-            VLOG_INFO("RTM_GETLINK failed (%s), obtaining netdev stats "
-                      "via proc (you are probably running a pre-2.6.19 "
-                      "kernel)", ovs_strerror(error));
-            return false;
-        }
-    }
-}
-
 static void
 swap_uint64(uint64_t *a, uint64_t *b)
 {
@@ -1421,38 +1392,6 @@ get_stats_via_vport(const struct netdev *netdev_,
     }
 }
 
-static int
-netdev_linux_sys_get_stats(const struct netdev *netdev_,
-                           struct netdev_stats *stats)
-{
-    static struct ovsthread_once once = OVSTHREAD_ONCE_INITIALIZER;
-    static int use_netlink_stats;
-    int error;
-
-    if (ovsthread_once_start(&once)) {
-        use_netlink_stats = check_for_working_netlink_stats();
-        ovsthread_once_done(&once);
-    }
-
-    if (use_netlink_stats) {
-        int ifindex;
-
-        error = get_ifindex(netdev_, &ifindex);
-        if (!error) {
-            error = get_stats_via_netlink(ifindex, stats);
-        }
-    } else {
-        error = get_stats_via_proc(netdev_get_name(netdev_), stats);
-    }
-
-    if (error) {
-        VLOG_WARN_RL(&rl, "%s: linux-sys get stats failed %d",
-                      netdev_get_name(netdev_), error);
-    }
-    return error;
-
-}
-
 /* Retrieves current device stats for 'netdev-linux'. */
 static int
 netdev_linux_get_stats(const struct netdev *netdev_,
@@ -1464,7 +1403,7 @@ netdev_linux_get_stats(const struct netdev *netdev_,
 
     ovs_mutex_lock(&netdev->mutex);
     get_stats_via_vport(netdev_, stats);
-    error = netdev_linux_sys_get_stats(netdev_, &dev_stats);
+    error = get_stats_via_netlink(netdev_, &dev_stats);
     if (error) {
         if (!netdev->vport_stats_error) {
             error = 0;
@@ -1507,7 +1446,7 @@ netdev_tap_get_stats(const struct netdev *netdev_, struct netdev_stats *stats)
 
     ovs_mutex_lock(&netdev->mutex);
     get_stats_via_vport(netdev_, stats);
-    error = netdev_linux_sys_get_stats(netdev_, &dev_stats);
+    error = get_stats_via_netlink(netdev_, &dev_stats);
     if (error) {
         if (!netdev->vport_stats_error) {
             error = 0;
@@ -4473,7 +4412,7 @@ netdev_stats_from_rtnl_link_stats(struct netdev_stats *dst,
 }
 
 static int
-get_stats_via_netlink(int ifindex, struct netdev_stats *stats)
+get_stats_via_netlink(const struct netdev *netdev_, struct netdev_stats *stats)
 {
     /* Policy for RTNLGRP_LINK messages.
      *
@@ -4489,8 +4428,14 @@ get_stats_via_netlink(int ifindex, struct netdev_stats *stats)
     struct ofpbuf *reply;
     struct ifinfomsg *ifi;
     struct nlattr *attrs[ARRAY_SIZE(rtnlgrp_link_policy)];
+    int ifindex;
     int error;
 
+    error = get_ifindex(netdev_, &ifindex);
+    if (error) {
+        return error;
+    }
+
     ofpbuf_init(&request, 0);
     nl_msg_put_nlmsghdr(&request, sizeof *ifi, RTM_GETLINK, NLM_F_REQUEST);
     ifi = ofpbuf_put_zeros(&request, sizeof *ifi);
@@ -4520,63 +4465,7 @@ get_stats_via_netlink(int ifindex, struct netdev_stats *stats)
     ofpbuf_delete(reply);
 
     return 0;
-}
-
-static int
-get_stats_via_proc(const char *netdev_name, struct netdev_stats *stats)
-{
-    static const char fn[] = "/proc/net/dev";
-    char line[1024];
-    FILE *stream;
-    int ln;
-
-    stream = fopen(fn, "r");
-    if (!stream) {
-        VLOG_WARN_RL(&rl, "%s: open failed: %s", fn, ovs_strerror(errno));
-        return errno;
-    }
-
-    ln = 0;
-    while (fgets(line, sizeof line, stream)) {
-        if (++ln >= 3) {
-            char devname[16];
-#define X64 "%"SCNu64
-            if (!ovs_scan(line,
-                          " %15[^:]:"
-                          X64 X64 X64 X64 X64 X64 X64 "%*u"
-                          X64 X64 X64 X64 X64 X64 X64 "%*u",
-                          devname,
-                          &stats->rx_bytes,
-                          &stats->rx_packets,
-                          &stats->rx_errors,
-                          &stats->rx_dropped,
-                          &stats->rx_fifo_errors,
-                          &stats->rx_frame_errors,
-                          &stats->multicast,
-                          &stats->tx_bytes,
-                          &stats->tx_packets,
-                          &stats->tx_errors,
-                          &stats->tx_dropped,
-                          &stats->tx_fifo_errors,
-                          &stats->collisions,
-                          &stats->tx_carrier_errors)) {
-                VLOG_WARN_RL(&rl, "%s:%d: parse error", fn, ln);
-            } else if (!strcmp(devname, netdev_name)) {
-                stats->rx_length_errors = UINT64_MAX;
-                stats->rx_over_errors = UINT64_MAX;
-                stats->rx_crc_errors = UINT64_MAX;
-                stats->rx_missed_errors = UINT64_MAX;
-                stats->tx_aborted_errors = UINT64_MAX;
-                stats->tx_heartbeat_errors = UINT64_MAX;
-                stats->tx_window_errors = UINT64_MAX;
-                fclose(stream);
-                return 0;
-            }
-        }
-    }
-    VLOG_WARN_RL(&rl, "%s: no stats for %s", fn, netdev_name);
-    fclose(stream);
-    return ENODEV;
+    return error;
 }
 
 static int