[patch iproute2 rfc 2/2] ip: allow to use alternative names as handle

[Jiri Pirko]

From: Jiri Pirko <j...@mellanox.com>

Signed-off-by: Jiri Pirko <j...@mellanox.com>
---
 ip/iplink.c  |  5 +++--
 lib/ll_map.c | 41 ++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 43 insertions(+), 3 deletions(-)

diff --git a/ip/iplink.c b/ip/iplink.c
index 45f975f1dce9..ad1e67761dd8 100644
--- a/ip/iplink.c
+++ b/ip/iplink.c
@@ -929,7 +929,7 @@ int iplink_parse(int argc, char **argv, struct iplink_req 
*req, char **type)
                                NEXT_ARG();
                        if (dev != name)
                                duparg2("dev", *argv);
-                       if (check_ifname(*argv))
+                       if (check_altifname(*argv))
                                invarg("\"dev\" not a valid ifname", *argv);
                        dev = *argv;
                }
@@ -1104,7 +1104,8 @@ int iplink_get(char *name, __u32 filt_mask)
 
        if (name) {
                addattr_l(&req.n, sizeof(req),
-                         IFLA_IFNAME, name, strlen(name) + 1);
+                         check_ifname(name) ? IFLA_IFNAME : IFLA_ALT_IFNAME,
+                         name, strlen(name) + 1);
        }
        addattr32(&req.n, sizeof(req), IFLA_EXT_MASK, filt_mask);
 
diff --git a/lib/ll_map.c b/lib/ll_map.c
index e0ed54bf77c9..04dfb0f2320b 100644
--- a/lib/ll_map.c
+++ b/lib/ll_map.c
@@ -70,7 +70,7 @@ static struct ll_cache *ll_get_by_name(const char *name)
                struct ll_cache *im
                        = container_of(n, struct ll_cache, name_hash);
 
-               if (strncmp(im->name, name, IFNAMSIZ) == 0)
+               if (strcmp(im->name, name) == 0)
                        return im;
        }
 
@@ -240,6 +240,43 @@ int ll_index_to_flags(unsigned idx)
        return im ? im->flags : -1;
 }
 
+static int altnametoindex(const char *name)
+{
+       struct {
+               struct nlmsghdr         n;
+               struct ifinfomsg        ifm;
+               char                    buf[1024];
+       } req = {
+               .n.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg)),
+               .n.nlmsg_flags = NLM_F_REQUEST,
+               .n.nlmsg_type = RTM_GETLINK,
+       };
+       struct rtnl_handle rth = {};
+       struct nlmsghdr *answer;
+       struct ifinfomsg *ifm;
+       int rc = 0;
+
+       if (rtnl_open(&rth, 0) < 0)
+               return 0;
+
+       addattr32(&req.n, sizeof(req), IFLA_EXT_MASK,
+                 RTEXT_FILTER_VF | RTEXT_FILTER_SKIP_STATS);
+       addattr_l(&req.n, sizeof(req), IFLA_ALT_IFNAME, name, strlen(name) + 1);
+
+       if (rtnl_talk_suppress_rtnl_errmsg(&rth, &req.n, &answer) < 0)
+               goto out;
+
+       ifm = NLMSG_DATA(answer);
+       rc = ifm->ifi_index;
+
+       free(answer);
+
+       rtnl_close(&rth);
+out:
+       return rc;
+}
+
+
 unsigned ll_name_to_index(const char *name)
 {
        const struct ll_cache *im;
@@ -257,6 +294,8 @@ unsigned ll_name_to_index(const char *name)
                idx = if_nametoindex(name);
        if (idx == 0)
                idx = ll_idx_a2n(name);
+       if (idx == 0)
+               idx = altnametoindex(name);
        return idx;
 }
 
-- 
2.21.0