link : add support to configure Offload features (#4017)

This patch supports these features to be on or off

Generic Segmentation Offload
TCP Segmentation Offload
UDP Segmentation Offload

fixes #432

1 files changed, 111 insertions, 0 deletions

diff --git a/src/udev/net/ethtool-util.c b/src/udev/net/ethtool-util.c
index c00ff79123..5143eb5a9d 100644
--- a/src/udev/net/ethtool-util.c
+++ b/src/udev/net/ethtool-util.c
@@ -46,6 +46,12 @@ static const char* const wol_table[_WOL_MAX] = {
 DEFINE_STRING_TABLE_LOOKUP(wol, WakeOnLan);
 DEFINE_CONFIG_PARSE_ENUM(config_parse_wol, wol, WakeOnLan, "Failed to parse WakeOnLan setting");
 
+static const char* const netdev_feature_table[_NET_DEV_FEAT_MAX] = {
+        [NET_DEV_FEAT_GSO] = "tx-generic-segmentation",
+        [NET_DEV_FEAT_TSO] = "tx-tcp-segmentation",
+        [NET_DEV_FEAT_UFO] = "tx-udp-fragmentation",
+};
+
 int ethtool_connect(int *ret) {
         int fd;
 
@@ -206,3 +212,108 @@ int ethtool_set_wol(int *fd, const char *ifname, WakeOnLan wol) {
 
         return 0;
 }
+
+static int ethtool_get_stringset(int *fd, struct ifreq *ifr, int stringset_id, struct ethtool_gstrings **gstrings) {
+        _cleanup_free_ struct ethtool_gstrings *strings = NULL;
+        struct ethtool_sset_info info =  {
+                .cmd = ETHTOOL_GSSET_INFO,
+                .reserved = 0,
+                .sset_mask = 1ULL << stringset_id,
+        };
+        unsigned len;
+        int r;
+
+        ifr->ifr_data = (void *) &info;
+
+        r = ioctl(*fd, SIOCETHTOOL, ifr);
+        if (r < 0)
+                return -errno;
+
+        if (!info.sset_mask)
+                return -EINVAL;
+
+        len = info.data[0];
+
+        strings = malloc0(sizeof(struct ethtool_gstrings) + len * ETH_GSTRING_LEN);
+        if (!strings)
+                return -ENOMEM;
+
+        strings->cmd = ETHTOOL_GSTRINGS;
+        strings->string_set = stringset_id;
+        strings->len = len;
+
+        ifr->ifr_data = (void *) strings;
+
+        r = ioctl(*fd, SIOCETHTOOL, ifr);
+        if (r < 0)
+                return -errno;
+
+        *gstrings = strings;
+        strings = NULL;
+
+        return 0;
+}
+
+static int find_feature_index(struct ethtool_gstrings *strings, const char *feature) {
+        unsigned i;
+
+        for (i = 0; i < strings->len; i++) {
+                if (streq((char *) &strings->data[i * ETH_GSTRING_LEN], feature))
+                        return i;
+        }
+
+        return -1;
+}
+
+int ethtool_set_features(int *fd, const char *ifname, NetDevFeature *features) {
+        _cleanup_free_ struct ethtool_gstrings *strings = NULL;
+        struct ethtool_sfeatures *sfeatures;
+        int block, bit, i, r;
+        struct ifreq ifr;
+
+        if (*fd < 0) {
+                r = ethtool_connect(fd);
+                if (r < 0)
+                        return log_warning_errno(r, "link_config: could not connect to ethtool: %m");
+        }
+
+        strscpy(ifr.ifr_name, IFNAMSIZ, ifname);
+
+        r = ethtool_get_stringset(fd, &ifr, ETH_SS_FEATURES, &strings);
+        if (r < 0)
+                return log_warning_errno(r, "link_config: could not get ethtool features for %s", ifname);
+
+        sfeatures = alloca0(sizeof(struct ethtool_gstrings) + DIV_ROUND_UP(strings->len, 32U) * sizeof(sfeatures->features[0]));
+        sfeatures->cmd = ETHTOOL_SFEATURES;
+        sfeatures->size = DIV_ROUND_UP(strings->len, 32U);
+
+        for (i = 0; i < _NET_DEV_FEAT_MAX; i++) {
+
+                if (features[i] != -1) {
+
+                        r = find_feature_index(strings, netdev_feature_table[i]);
+                        if (r < 0) {
+                                log_warning_errno(r, "link_config: could not find feature: %s", netdev_feature_table[i]);
+                                continue;
+                        }
+
+                        block = r / 32;
+                        bit = r % 32;
+
+                        sfeatures->features[block].valid |= 1 << bit;
+
+                        if (features[i])
+                                sfeatures->features[block].requested |= 1 << bit;
+                        else
+                                sfeatures->features[block].requested &= ~(1 << bit);
+                }
+        }
+
+        ifr.ifr_data = (void *) sfeatures;
+
+        r = ioctl(*fd, SIOCETHTOOL, &ifr);
+        if (r < 0)
+                return log_warning_errno(r, "link_config: could not set ethtool features for %s", ifname);
+
+        return 0;
+}