From 84920c1420e2b4a4150e5bb45ee5a23ea4641523 Mon Sep 17 00:00:00 2001 From: Tony Zelenoff Date: Thu, 26 Jan 2012 22:28:58 +0000 Subject: [PATCH] net: Allow ipv6 proxies and arp proxies be shown with iproute2 Add ability to return neighbour proxies list to caller if it sent full ndmsg structure and has NTF_PROXY flag set. Before this patch (and before iproute2 patches): $ ip neigh add proxy 2001::1 dev eth0 $ ip -6 neigh show $ After it and with applied iproute2 patches: $ ip neigh add proxy 2001::1 dev eth0 $ ip -6 neigh show 2001::1 dev eth0 proxy $ Compatibility with old versions of iproute2 is not broken, kernel checks for incoming structure size and properly works if old structure is came. [v2] * changed comments style. * removed useless line with continue and curly bracket. * changed incoming message size check from equal to more or equal. CC: davem@davemloft.net CC: kuznet@ms2.inr.ac.ru CC: netdev@vger.kernel.org CC: xemul@parallels.com Signed-off-by: Tony Zelenoff Acked-by: Thomas Graf Signed-off-by: David S. Miller --- net/core/neighbour.c | 90 ++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 87 insertions(+), 3 deletions(-) diff --git a/net/core/neighbour.c b/net/core/neighbour.c index e287346e0934..f98ec444133a 100644 --- a/net/core/neighbour.c +++ b/net/core/neighbour.c @@ -2165,6 +2165,35 @@ nla_put_failure: return -EMSGSIZE; } +static int pneigh_fill_info(struct sk_buff *skb, struct pneigh_entry *pn, + u32 pid, u32 seq, int type, unsigned int flags, + struct neigh_table *tbl) +{ + struct nlmsghdr *nlh; + struct ndmsg *ndm; + + nlh = nlmsg_put(skb, pid, seq, type, sizeof(*ndm), flags); + if (nlh == NULL) + return -EMSGSIZE; + + ndm = nlmsg_data(nlh); + ndm->ndm_family = tbl->family; + ndm->ndm_pad1 = 0; + ndm->ndm_pad2 = 0; + ndm->ndm_flags = pn->flags | NTF_PROXY; + ndm->ndm_type = NDA_DST; + ndm->ndm_ifindex = pn->dev->ifindex; + ndm->ndm_state = NUD_NONE; + + NLA_PUT(skb, NDA_DST, tbl->key_len, pn->key); + + return nlmsg_end(skb, nlh); + +nla_put_failure: + nlmsg_cancel(skb, nlh); + return -EMSGSIZE; +} + static void neigh_update_notify(struct neighbour *neigh) { call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, neigh); @@ -2214,23 +2243,78 @@ out: return rc; } +static int pneigh_dump_table(struct neigh_table *tbl, struct sk_buff *skb, + struct netlink_callback *cb) +{ + struct pneigh_entry *n; + struct net *net = sock_net(skb->sk); + int rc, h, s_h = cb->args[3]; + int idx, s_idx = idx = cb->args[4]; + + read_lock_bh(&tbl->lock); + + for (h = 0; h <= PNEIGH_HASHMASK; h++) { + if (h < s_h) + continue; + if (h > s_h) + s_idx = 0; + for (n = tbl->phash_buckets[h], idx = 0; n; n = n->next) { + if (dev_net(n->dev) != net) + continue; + if (idx < s_idx) + goto next; + if (pneigh_fill_info(skb, n, NETLINK_CB(cb->skb).pid, + cb->nlh->nlmsg_seq, + RTM_NEWNEIGH, + NLM_F_MULTI, tbl) <= 0) { + read_unlock_bh(&tbl->lock); + rc = -1; + goto out; + } + next: + idx++; + } + } + + read_unlock_bh(&tbl->lock); + rc = skb->len; +out: + cb->args[3] = h; + cb->args[4] = idx; + return rc; + +} + static int neigh_dump_info(struct sk_buff *skb, struct netlink_callback *cb) { struct neigh_table *tbl; int t, family, s_t; + int proxy = 0; + int err = 0; read_lock(&neigh_tbl_lock); family = ((struct rtgenmsg *) nlmsg_data(cb->nlh))->rtgen_family; + + /* check for full ndmsg structure presence, family member is + * the same for both structures + */ + if (nlmsg_len(cb->nlh) >= sizeof(struct ndmsg) && + ((struct ndmsg *) nlmsg_data(cb->nlh))->ndm_flags == NTF_PROXY) + proxy = 1; + s_t = cb->args[0]; - for (tbl = neigh_tables, t = 0; tbl; tbl = tbl->next, t++) { + for (tbl = neigh_tables, t = 0; tbl && (err >= 0); + tbl = tbl->next, t++) { if (t < s_t || (family && tbl->family != family)) continue; if (t > s_t) memset(&cb->args[1], 0, sizeof(cb->args) - sizeof(cb->args[0])); - if (neigh_dump_table(tbl, skb, cb) < 0) - break; + if (proxy) + err = pneigh_dump_table(tbl, skb, cb); + else + err = neigh_dump_table(tbl, skb, cb); } read_unlock(&neigh_tbl_lock); -- 2.20.1