From 5d3cae8bc39dd38d1aa5fd4bbc788c7b43fcaa71 Mon Sep 17 00:00:00 2001 From: Pavel Emelyanov Date: Thu, 15 Dec 2011 02:45:07 +0000 Subject: [PATCH] unix_diag: Dumping exact socket core The socket inode is used as a key for lookup. This is effectively the only really unique ID of a unix socket, but using this for search currently has one problem -- it is O(number of sockets) :( Does it worth fixing this lookup or inventing some other ID for unix sockets? Signed-off-by: Pavel Emelyanov Signed-off-by: David S. Miller --- net/unix/diag.c | 67 ++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 66 insertions(+), 1 deletion(-) diff --git a/net/unix/diag.c b/net/unix/diag.c index 86d85abf90c6..d7bd48c49ee5 100644 --- a/net/unix/diag.c +++ b/net/unix/diag.c @@ -89,11 +89,76 @@ done: return skb->len; } +static struct sock *unix_lookup_by_ino(int ino) +{ + int i; + struct sock *sk; + + spin_lock(&unix_table_lock); + for (i = 0; i <= UNIX_HASH_SIZE; i++) { + struct hlist_node *node; + + sk_for_each(sk, node, &unix_socket_table[i]) + if (ino == sock_i_ino(sk)) { + sock_hold(sk); + spin_unlock(&unix_table_lock); + + return sk; + } + } + + spin_unlock(&unix_table_lock); + return NULL; +} + static int unix_diag_get_exact(struct sk_buff *in_skb, const struct nlmsghdr *nlh, struct unix_diag_req *req) { - return -EAFNOSUPPORT; + int err = -EINVAL; + struct sock *sk; + struct sk_buff *rep; + unsigned int extra_len; + + if (req->udiag_ino == 0) + goto out_nosk; + + sk = unix_lookup_by_ino(req->udiag_ino); + err = -ENOENT; + if (sk == NULL) + goto out_nosk; + + err = sock_diag_check_cookie(sk, req->udiag_cookie); + if (err) + goto out; + + extra_len = 256; +again: + err = -ENOMEM; + rep = alloc_skb(NLMSG_SPACE((sizeof(struct unix_diag_msg) + extra_len)), + GFP_KERNEL); + if (!rep) + goto out; + + err = sk_diag_fill(sk, rep, req, NETLINK_CB(in_skb).pid, + nlh->nlmsg_seq, 0, req->udiag_ino); + if (err < 0) { + kfree_skb(rep); + extra_len += 256; + if (extra_len >= PAGE_SIZE) + goto out; + + goto again; + } + err = netlink_unicast(sock_diag_nlsk, rep, NETLINK_CB(in_skb).pid, + MSG_DONTWAIT); + if (err > 0) + err = 0; +out: + if (sk) + sock_put(sk); +out_nosk: + return err; } static int unix_diag_handler_dump(struct sk_buff *skb, struct nlmsghdr *h) -- 2.20.1