From 83321d6b9872b94604e481a79dc2c8acbe4ece31 Mon Sep 17 00:00:00 2001 From: Timo Teras Date: Mon, 3 Mar 2008 23:40:12 -0800 Subject: [PATCH] [AF_KEY]: Dump SA/SP entries non-atomically Stop dumping of entries when af_key socket receive queue is getting full and continue it later when there is more room again. This fixes dumping of large databases. Currently the entries not fitting into the receive queue are just dropped (including the end-of-dump message) which can confuse applications. Signed-off-by: Timo Teras Signed-off-by: David S. Miller --- net/key/af_key.c | 120 +++++++++++++++++++++++++++++++++++------------ 1 file changed, 91 insertions(+), 29 deletions(-) diff --git a/net/key/af_key.c b/net/key/af_key.c index 7cb6f1213360..50c442fc99ce 100644 --- a/net/key/af_key.c +++ b/net/key/af_key.c @@ -48,6 +48,17 @@ struct pfkey_sock { struct sock sk; int registered; int promisc; + + struct { + uint8_t msg_version; + uint32_t msg_pid; + int (*dump)(struct pfkey_sock *sk); + void (*done)(struct pfkey_sock *sk); + union { + struct xfrm_policy_walk policy; + struct xfrm_state_walk state; + } u; + } dump; }; static inline struct pfkey_sock *pfkey_sk(struct sock *sk) @@ -55,6 +66,27 @@ static inline struct pfkey_sock *pfkey_sk(struct sock *sk) return (struct pfkey_sock *)sk; } +static int pfkey_can_dump(struct sock *sk) +{ + if (3 * atomic_read(&sk->sk_rmem_alloc) <= 2 * sk->sk_rcvbuf) + return 1; + return 0; +} + +static int pfkey_do_dump(struct pfkey_sock *pfk) +{ + int rc; + + rc = pfk->dump.dump(pfk); + if (rc == -ENOBUFS) + return 0; + + pfk->dump.done(pfk); + pfk->dump.dump = NULL; + pfk->dump.done = NULL; + return rc; +} + static void pfkey_sock_destruct(struct sock *sk) { skb_queue_purge(&sk->sk_receive_queue); @@ -1709,51 +1741,60 @@ static int pfkey_flush(struct sock *sk, struct sk_buff *skb, struct sadb_msg *hd return 0; } -struct pfkey_dump_data -{ - struct sk_buff *skb; - struct sadb_msg *hdr; - struct sock *sk; -}; - static int dump_sa(struct xfrm_state *x, int count, void *ptr) { - struct pfkey_dump_data *data = ptr; + struct pfkey_sock *pfk = ptr; struct sk_buff *out_skb; struct sadb_msg *out_hdr; + if (!pfkey_can_dump(&pfk->sk)) + return -ENOBUFS; + out_skb = pfkey_xfrm_state2msg(x); if (IS_ERR(out_skb)) return PTR_ERR(out_skb); out_hdr = (struct sadb_msg *) out_skb->data; - out_hdr->sadb_msg_version = data->hdr->sadb_msg_version; + out_hdr->sadb_msg_version = pfk->dump.msg_version; out_hdr->sadb_msg_type = SADB_DUMP; out_hdr->sadb_msg_satype = pfkey_proto2satype(x->id.proto); out_hdr->sadb_msg_errno = 0; out_hdr->sadb_msg_reserved = 0; out_hdr->sadb_msg_seq = count; - out_hdr->sadb_msg_pid = data->hdr->sadb_msg_pid; - pfkey_broadcast(out_skb, GFP_ATOMIC, BROADCAST_ONE, data->sk); + out_hdr->sadb_msg_pid = pfk->dump.msg_pid; + pfkey_broadcast(out_skb, GFP_ATOMIC, BROADCAST_ONE, &pfk->sk); return 0; } +static int pfkey_dump_sa(struct pfkey_sock *pfk) +{ + return xfrm_state_walk(&pfk->dump.u.state, dump_sa, (void *) pfk); +} + +static void pfkey_dump_sa_done(struct pfkey_sock *pfk) +{ + xfrm_state_walk_done(&pfk->dump.u.state); +} + static int pfkey_dump(struct sock *sk, struct sk_buff *skb, struct sadb_msg *hdr, void **ext_hdrs) { u8 proto; - struct pfkey_dump_data data = { .skb = skb, .hdr = hdr, .sk = sk }; - struct xfrm_state_walk walk; - int rc; + struct pfkey_sock *pfk = pfkey_sk(sk); + + if (pfk->dump.dump != NULL) + return -EBUSY; proto = pfkey_satype2proto(hdr->sadb_msg_satype); if (proto == 0) return -EINVAL; - xfrm_state_walk_init(&walk, proto); - rc = xfrm_state_walk(&walk, dump_sa, &data); - xfrm_state_walk_done(&walk); + pfk->dump.msg_version = hdr->sadb_msg_version; + pfk->dump.msg_pid = hdr->sadb_msg_pid; + pfk->dump.dump = pfkey_dump_sa; + pfk->dump.done = pfkey_dump_sa_done; + xfrm_state_walk_init(&pfk->dump.u.state, proto); - return rc; + return pfkey_do_dump(pfk); } static int pfkey_promisc(struct sock *sk, struct sk_buff *skb, struct sadb_msg *hdr, void **ext_hdrs) @@ -2648,11 +2689,14 @@ static int pfkey_spdget(struct sock *sk, struct sk_buff *skb, struct sadb_msg *h static int dump_sp(struct xfrm_policy *xp, int dir, int count, void *ptr) { - struct pfkey_dump_data *data = ptr; + struct pfkey_sock *pfk = ptr; struct sk_buff *out_skb; struct sadb_msg *out_hdr; int err; + if (!pfkey_can_dump(&pfk->sk)) + return -ENOBUFS; + out_skb = pfkey_xfrm_policy2msg_prep(xp); if (IS_ERR(out_skb)) return PTR_ERR(out_skb); @@ -2662,27 +2706,40 @@ static int dump_sp(struct xfrm_policy *xp, int dir, int count, void *ptr) return err; out_hdr = (struct sadb_msg *) out_skb->data; - out_hdr->sadb_msg_version = data->hdr->sadb_msg_version; + out_hdr->sadb_msg_version = pfk->dump.msg_version; out_hdr->sadb_msg_type = SADB_X_SPDDUMP; out_hdr->sadb_msg_satype = SADB_SATYPE_UNSPEC; out_hdr->sadb_msg_errno = 0; out_hdr->sadb_msg_seq = count; - out_hdr->sadb_msg_pid = data->hdr->sadb_msg_pid; - pfkey_broadcast(out_skb, GFP_ATOMIC, BROADCAST_ONE, data->sk); + out_hdr->sadb_msg_pid = pfk->dump.msg_pid; + pfkey_broadcast(out_skb, GFP_ATOMIC, BROADCAST_ONE, &pfk->sk); return 0; } +static int pfkey_dump_sp(struct pfkey_sock *pfk) +{ + return xfrm_policy_walk(&pfk->dump.u.policy, dump_sp, (void *) pfk); +} + +static void pfkey_dump_sp_done(struct pfkey_sock *pfk) +{ + xfrm_policy_walk_done(&pfk->dump.u.policy); +} + static int pfkey_spddump(struct sock *sk, struct sk_buff *skb, struct sadb_msg *hdr, void **ext_hdrs) { - struct pfkey_dump_data data = { .skb = skb, .hdr = hdr, .sk = sk }; - struct xfrm_policy_walk walk; - int rc; + struct pfkey_sock *pfk = pfkey_sk(sk); - xfrm_policy_walk_init(&walk, XFRM_POLICY_TYPE_MAIN); - rc = xfrm_policy_walk(&walk, dump_sp, &data); - xfrm_policy_walk_done(&walk); + if (pfk->dump.dump != NULL) + return -EBUSY; - return rc; + pfk->dump.msg_version = hdr->sadb_msg_version; + pfk->dump.msg_pid = hdr->sadb_msg_pid; + pfk->dump.dump = pfkey_dump_sp; + pfk->dump.done = pfkey_dump_sp_done; + xfrm_policy_walk_init(&pfk->dump.u.policy, XFRM_POLICY_TYPE_MAIN); + + return pfkey_do_dump(pfk); } static int key_notify_policy_flush(struct km_event *c) @@ -3687,6 +3744,7 @@ static int pfkey_recvmsg(struct kiocb *kiocb, int flags) { struct sock *sk = sock->sk; + struct pfkey_sock *pfk = pfkey_sk(sk); struct sk_buff *skb; int copied, err; @@ -3714,6 +3772,10 @@ static int pfkey_recvmsg(struct kiocb *kiocb, err = (flags & MSG_TRUNC) ? skb->len : copied; + if (pfk->dump.dump != NULL && + 3 * atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf) + pfkey_do_dump(pfk); + out_free: skb_free_datagram(sk, skb); out: -- GitLab