From ca065d0cf80fa547724440a8bf37f1e674d917c0 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Fri, 1 Apr 2016 08:52:13 -0700 Subject: [PATCH] udp: no longer use SLAB_DESTROY_BY_RCU Tom Herbert would like not touching UDP socket refcnt for encapsulated traffic. For this to happen, we need to use normal RCU rules, with a grace period before freeing a socket. UDP sockets are not short lived in the high usage case, so the added cost of call_rcu() should not be a concern. This actually removes a lot of complexity in UDP stack. Multicast receives no longer need to hold a bucket spinlock. Note that ip early demux still needs to take a reference on the socket. Same remark for functions used by xt_socket and xt_PROXY netfilter modules, but this might be changed later. Performance for a single UDP socket receiving flood traffic from many RX queues/cpus. Simple udp_rx using simple recvfrom() loop : 438 kpps instead of 374 kpps : 17 % increase of the peak rate. v2: Addressed Willem de Bruijn feedback in multicast handling - keep early demux break in __udp4_lib_demux_lookup() Signed-off-by: Eric Dumazet Cc: Tom Herbert Cc: Willem de Bruijn Tested-by: Tom Herbert Signed-off-by: David S. Miller --- include/linux/udp.h | 8 +- include/net/sock.h | 12 +- include/net/udp.h | 2 +- net/ipv4/udp.c | 293 +++++++++++++------------------------------- net/ipv4/udp_diag.c | 18 +-- net/ipv6/udp.c | 196 ++++++++++------------------- 6 files changed, 171 insertions(+), 358 deletions(-) diff --git a/include/linux/udp.h b/include/linux/udp.h index 87c094961bd5..32342754643a 100644 --- a/include/linux/udp.h +++ b/include/linux/udp.h @@ -98,11 +98,11 @@ static inline bool udp_get_no_check6_rx(struct sock *sk) return udp_sk(sk)->no_check6_rx; } -#define udp_portaddr_for_each_entry(__sk, node, list) \ - hlist_nulls_for_each_entry(__sk, node, list, __sk_common.skc_portaddr_node) +#define udp_portaddr_for_each_entry(__sk, list) \ + hlist_for_each_entry(__sk, list, __sk_common.skc_portaddr_node) -#define udp_portaddr_for_each_entry_rcu(__sk, node, list) \ - hlist_nulls_for_each_entry_rcu(__sk, node, list, __sk_common.skc_portaddr_node) +#define udp_portaddr_for_each_entry_rcu(__sk, list) \ + hlist_for_each_entry_rcu(__sk, list, __sk_common.skc_portaddr_node) #define IS_UDPLITE(__sk) (udp_sk(__sk)->pcflag) diff --git a/include/net/sock.h b/include/net/sock.h index 9e77353a92ae..7ad73db9dde2 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -178,7 +178,7 @@ struct sock_common { int skc_bound_dev_if; union { struct hlist_node skc_bind_node; - struct hlist_nulls_node skc_portaddr_node; + struct hlist_node skc_portaddr_node; }; struct proto *skc_prot; possible_net_t skc_net; @@ -670,18 +670,18 @@ static inline void sk_add_bind_node(struct sock *sk, hlist_for_each_entry(__sk, list, sk_bind_node) /** - * sk_nulls_for_each_entry_offset - iterate over a list at a given struct offset + * sk_for_each_entry_offset_rcu - iterate over a list at a given struct offset * @tpos: the type * to use as a loop cursor. * @pos: the &struct hlist_node to use as a loop cursor. * @head: the head for your list. * @offset: offset of hlist_node within the struct. * */ -#define sk_nulls_for_each_entry_offset(tpos, pos, head, offset) \ - for (pos = (head)->first; \ - (!is_a_nulls(pos)) && \ +#define sk_for_each_entry_offset_rcu(tpos, pos, head, offset) \ + for (pos = rcu_dereference((head)->first); \ + pos != NULL && \ ({ tpos = (typeof(*tpos) *)((void *)pos - offset); 1;}); \ - pos = pos->next) + pos = rcu_dereference(pos->next)) static inline struct user_namespace *sk_user_ns(struct sock *sk) { diff --git a/include/net/udp.h b/include/net/udp.h index 92927f729ac8..d870ec1611c4 100644 --- a/include/net/udp.h +++ b/include/net/udp.h @@ -59,7 +59,7 @@ struct udp_skb_cb { * @lock: spinlock protecting changes to head/count */ struct udp_hslot { - struct hlist_nulls_head head; + struct hlist_head head; int count; spinlock_t lock; } __attribute__((aligned(2 * sizeof(long)))); diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index 45ff590661f4..355bdb221057 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -143,10 +143,9 @@ static int udp_lib_lport_inuse(struct net *net, __u16 num, unsigned int log) { struct sock *sk2; - struct hlist_nulls_node *node; kuid_t uid = sock_i_uid(sk); - sk_nulls_for_each(sk2, node, &hslot->head) { + sk_for_each(sk2, &hslot->head) { if (net_eq(sock_net(sk2), net) && sk2 != sk && (bitmap || udp_sk(sk2)->udp_port_hash == num) && @@ -177,12 +176,11 @@ static int udp_lib_lport_inuse2(struct net *net, __u16 num, bool match_wildcard)) { struct sock *sk2; - struct hlist_nulls_node *node; kuid_t uid = sock_i_uid(sk); int res = 0; spin_lock(&hslot2->lock); - udp_portaddr_for_each_entry(sk2, node, &hslot2->head) { + udp_portaddr_for_each_entry(sk2, &hslot2->head) { if (net_eq(sock_net(sk2), net) && sk2 != sk && (udp_sk(sk2)->udp_port_hash == num) && @@ -207,11 +205,10 @@ static int udp_reuseport_add_sock(struct sock *sk, struct udp_hslot *hslot, bool match_wildcard)) { struct net *net = sock_net(sk); - struct hlist_nulls_node *node; kuid_t uid = sock_i_uid(sk); struct sock *sk2; - sk_nulls_for_each(sk2, node, &hslot->head) { + sk_for_each(sk2, &hslot->head) { if (net_eq(sock_net(sk2), net) && sk2 != sk && sk2->sk_family == sk->sk_family && @@ -333,17 +330,18 @@ found: goto fail_unlock; } - sk_nulls_add_node_rcu(sk, &hslot->head); + sk_add_node_rcu(sk, &hslot->head); hslot->count++; sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1); hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash); spin_lock(&hslot2->lock); - hlist_nulls_add_head_rcu(&udp_sk(sk)->udp_portaddr_node, + hlist_add_head_rcu(&udp_sk(sk)->udp_portaddr_node, &hslot2->head); hslot2->count++; spin_unlock(&hslot2->lock); } + sock_set_flag(sk, SOCK_RCU_FREE); error = 0; fail_unlock: spin_unlock_bh(&hslot->lock); @@ -497,37 +495,27 @@ static struct sock *udp4_lib_lookup2(struct net *net, struct sk_buff *skb) { struct sock *sk, *result; - struct hlist_nulls_node *node; int score, badness, matches = 0, reuseport = 0; - bool select_ok = true; u32 hash = 0; -begin: result = NULL; badness = 0; - udp_portaddr_for_each_entry_rcu(sk, node, &hslot2->head) { + udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) { score = compute_score2(sk, net, saddr, sport, daddr, hnum, dif); if (score > badness) { - result = sk; - badness = score; reuseport = sk->sk_reuseport; if (reuseport) { hash = udp_ehashfn(net, daddr, hnum, saddr, sport); - if (select_ok) { - struct sock *sk2; - - sk2 = reuseport_select_sock(sk, hash, skb, + result = reuseport_select_sock(sk, hash, skb, sizeof(struct udphdr)); - if (sk2) { - result = sk2; - select_ok = false; - goto found; - } - } + if (result) + return result; matches = 1; } + badness = score; + result = sk; } else if (score == badness && reuseport) { matches++; if (reciprocal_scale(hash, matches) == 0) @@ -535,23 +523,6 @@ begin: hash = next_pseudo_random32(hash); } } - /* - * if the nulls value we got at the end of this lookup is - * not the expected one, we must restart lookup. - * We probably met an item that was moved to another chain. - */ - if (get_nulls_value(node) != slot2) - goto begin; - if (result) { -found: - if (unlikely(!atomic_inc_not_zero_hint(&result->sk_refcnt, 2))) - result = NULL; - else if (unlikely(compute_score2(result, net, saddr, sport, - daddr, hnum, dif) < badness)) { - sock_put(result); - goto begin; - } - } return result; } @@ -563,15 +534,12 @@ struct sock *__udp4_lib_lookup(struct net *net, __be32 saddr, int dif, struct udp_table *udptable, struct sk_buff *skb) { struct sock *sk, *result; - struct hlist_nulls_node *node; unsigned short hnum = ntohs(dport); unsigned int hash2, slot2, slot = udp_hashfn(net, hnum, udptable->mask); struct udp_hslot *hslot2, *hslot = &udptable->hash[slot]; int score, badness, matches = 0, reuseport = 0; - bool select_ok = true; u32 hash = 0; - rcu_read_lock(); if (hslot->count > 10) { hash2 = udp4_portaddr_hash(net, daddr, hnum); slot2 = hash2 & udptable->mask; @@ -593,35 +561,27 @@ struct sock *__udp4_lib_lookup(struct net *net, __be32 saddr, htonl(INADDR_ANY), hnum, dif, hslot2, slot2, skb); } - rcu_read_unlock(); return result; } begin: result = NULL; badness = 0; - sk_nulls_for_each_rcu(sk, node, &hslot->head) { + sk_for_each_rcu(sk, &hslot->head) { score = compute_score(sk, net, saddr, hnum, sport, daddr, dport, dif); if (score > badness) { - result = sk; - badness = score; reuseport = sk->sk_reuseport; if (reuseport) { hash = udp_ehashfn(net, daddr, hnum, saddr, sport); - if (select_ok) { - struct sock *sk2; - - sk2 = reuseport_select_sock(sk, hash, skb, + result = reuseport_select_sock(sk, hash, skb, sizeof(struct udphdr)); - if (sk2) { - result = sk2; - select_ok = false; - goto found; - } - } + if (result) + return result; matches = 1; } + result = sk; + badness = score; } else if (score == badness && reuseport) { matches++; if (reciprocal_scale(hash, matches) == 0) @@ -629,25 +589,6 @@ begin: hash = next_pseudo_random32(hash); } } - /* - * if the nulls value we got at the end of this lookup is - * not the expected one, we must restart lookup. - * We probably met an item that was moved to another chain. - */ - if (get_nulls_value(node) != slot) - goto begin; - - if (result) { -found: - if (unlikely(!atomic_inc_not_zero_hint(&result->sk_refcnt, 2))) - result = NULL; - else if (unlikely(compute_score(result, net, saddr, hnum, sport, - daddr, dport, dif) < badness)) { - sock_put(result); - goto begin; - } - } - rcu_read_unlock(); return result; } EXPORT_SYMBOL_GPL(__udp4_lib_lookup); @@ -663,13 +604,24 @@ static inline struct sock *__udp4_lib_lookup_skb(struct sk_buff *skb, udptable, skb); } +/* Must be called under rcu_read_lock(). + * Does increment socket refcount. + */ +#if IS_ENABLED(CONFIG_NETFILTER_XT_MATCH_SOCKET) || \ + IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TPROXY) struct sock *udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport, __be32 daddr, __be16 dport, int dif) { - return __udp4_lib_lookup(net, saddr, sport, daddr, dport, dif, - &udp_table, NULL); + struct sock *sk; + + sk = __udp4_lib_lookup(net, saddr, sport, daddr, dport, + dif, &udp_table, NULL); + if (sk && !atomic_inc_not_zero(&sk->sk_refcnt)) + sk = NULL; + return sk; } EXPORT_SYMBOL_GPL(udp4_lib_lookup); +#endif static inline bool __udp_is_mcast_sock(struct net *net, struct sock *sk, __be16 loc_port, __be32 loc_addr, @@ -771,7 +723,7 @@ void __udp4_lib_err(struct sk_buff *skb, u32 info, struct udp_table *udptable) sk->sk_err = err; sk->sk_error_report(sk); out: - sock_put(sk); + return; } void udp_err(struct sk_buff *skb, u32 info) @@ -1474,13 +1426,13 @@ void udp_lib_unhash(struct sock *sk) spin_lock_bh(&hslot->lock); if (rcu_access_pointer(sk->sk_reuseport_cb)) reuseport_detach_sock(sk); - if (sk_nulls_del_node_init_rcu(sk)) { + if (sk_del_node_init_rcu(sk)) { hslot->count--; inet_sk(sk)->inet_num = 0; sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1); spin_lock(&hslot2->lock); - hlist_nulls_del_init_rcu(&udp_sk(sk)->udp_portaddr_node); + hlist_del_init_rcu(&udp_sk(sk)->udp_portaddr_node); hslot2->count--; spin_unlock(&hslot2->lock); } @@ -1513,12 +1465,12 @@ void udp_lib_rehash(struct sock *sk, u16 newhash) if (hslot2 != nhslot2) { spin_lock(&hslot2->lock); - hlist_nulls_del_init_rcu(&udp_sk(sk)->udp_portaddr_node); + hlist_del_init_rcu(&udp_sk(sk)->udp_portaddr_node); hslot2->count--; spin_unlock(&hslot2->lock); spin_lock(&nhslot2->lock); - hlist_nulls_add_head_rcu(&udp_sk(sk)->udp_portaddr_node, + hlist_add_head_rcu(&udp_sk(sk)->udp_portaddr_node, &nhslot2->head); nhslot2->count++; spin_unlock(&nhslot2->lock); @@ -1697,35 +1649,6 @@ drop: return -1; } -static void flush_stack(struct sock **stack, unsigned int count, - struct sk_buff *skb, unsigned int final) -{ - unsigned int i; - struct sk_buff *skb1 = NULL; - struct sock *sk; - - for (i = 0; i < count; i++) { - sk = stack[i]; - if (likely(!skb1)) - skb1 = (i == final) ? skb : skb_clone(skb, GFP_ATOMIC); - - if (!skb1) { - atomic_inc(&sk->sk_drops); - UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_RCVBUFERRORS, - IS_UDPLITE(sk)); - UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, - IS_UDPLITE(sk)); - } - - if (skb1 && udp_queue_rcv_skb(sk, skb1) <= 0) - skb1 = NULL; - - sock_put(sk); - } - if (unlikely(skb1)) - kfree_skb(skb1); -} - /* For TCP sockets, sk_rx_dst is protected by socket lock * For UDP, we use xchg() to guard against concurrent changes. */ @@ -1749,14 +1672,14 @@ static int __udp4_lib_mcast_deliver(struct net *net, struct sk_buff *skb, struct udp_table *udptable, int proto) { - struct sock *sk, *stack[256 / sizeof(struct sock *)]; - struct hlist_nulls_node *node; + struct sock *sk, *first = NULL; unsigned short hnum = ntohs(uh->dest); struct udp_hslot *hslot = udp_hashslot(udptable, net, hnum); - int dif = skb->dev->ifindex; - unsigned int count = 0, offset = offsetof(typeof(*sk), sk_nulls_node); unsigned int hash2 = 0, hash2_any = 0, use_hash2 = (hslot->count > 10); - bool inner_flushed = false; + unsigned int offset = offsetof(typeof(*sk), sk_node); + int dif = skb->dev->ifindex; + struct hlist_node *node; + struct sk_buff *nskb; if (use_hash2) { hash2_any = udp4_portaddr_hash(net, htonl(INADDR_ANY), hnum) & @@ -1767,23 +1690,28 @@ start_lookup: offset = offsetof(typeof(*sk), __sk_common.skc_portaddr_node); } - spin_lock(&hslot->lock); - sk_nulls_for_each_entry_offset(sk, node, &hslot->head, offset) { - if (__udp_is_mcast_sock(net, sk, - uh->dest, daddr, - uh->source, saddr, - dif, hnum)) { - if (unlikely(count == ARRAY_SIZE(stack))) { - flush_stack(stack, count, skb, ~0); - inner_flushed = true; - count = 0; - } - stack[count++] = sk; - sock_hold(sk); + sk_for_each_entry_offset_rcu(sk, node, &hslot->head, offset) { + if (!__udp_is_mcast_sock(net, sk, uh->dest, daddr, + uh->source, saddr, dif, hnum)) + continue; + + if (!first) { + first = sk; + continue; } - } + nskb = skb_clone(skb, GFP_ATOMIC); - spin_unlock(&hslot->lock); + if (unlikely(!nskb)) { + atomic_inc(&sk->sk_drops); + UDP_INC_STATS_BH(net, UDP_MIB_RCVBUFERRORS, + IS_UDPLITE(sk)); + UDP_INC_STATS_BH(net, UDP_MIB_INERRORS, + IS_UDPLITE(sk)); + continue; + } + if (udp_queue_rcv_skb(sk, nskb) > 0) + consume_skb(nskb); + } /* Also lookup *:port if we are using hash2 and haven't done so yet. */ if (use_hash2 && hash2 != hash2_any) { @@ -1791,16 +1719,13 @@ start_lookup: goto start_lookup; } - /* - * do the slow work with no lock held - */ - if (count) { - flush_stack(stack, count, skb, count - 1); + if (first) { + if (udp_queue_rcv_skb(first, skb) > 0) + consume_skb(skb); } else { - if (!inner_flushed) - UDP_INC_STATS_BH(net, UDP_MIB_IGNOREDMULTI, - proto == IPPROTO_UDPLITE); - consume_skb(skb); + kfree_skb(skb); + UDP_INC_STATS_BH(net, UDP_MIB_IGNOREDMULTI, + proto == IPPROTO_UDPLITE); } return 0; } @@ -1897,7 +1822,6 @@ int __udp4_lib_rcv(struct sk_buff *skb, struct udp_table *udptable, inet_compute_pseudo); ret = udp_queue_rcv_skb(sk, skb); - sock_put(sk); /* a return value > 0 means to resubmit the input, but * it wants the return to be -protocol, or 0 @@ -1958,49 +1882,24 @@ static struct sock *__udp4_lib_mcast_demux_lookup(struct net *net, int dif) { struct sock *sk, *result; - struct hlist_nulls_node *node; unsigned short hnum = ntohs(loc_port); - unsigned int count, slot = udp_hashfn(net, hnum, udp_table.mask); + unsigned int slot = udp_hashfn(net, hnum, udp_table.mask); struct udp_hslot *hslot = &udp_table.hash[slot]; /* Do not bother scanning a too big list */ if (hslot->count > 10) return NULL; - rcu_read_lock(); -begin: - count = 0; result = NULL; - sk_nulls_for_each_rcu(sk, node, &hslot->head) { - if (__udp_is_mcast_sock(net, sk, - loc_port, loc_addr, - rmt_port, rmt_addr, - dif, hnum)) { + sk_for_each_rcu(sk, &hslot->head) { + if (__udp_is_mcast_sock(net, sk, loc_port, loc_addr, + rmt_port, rmt_addr, dif, hnum)) { + if (result) + return NULL; result = sk; - ++count; - } - } - /* - * if the nulls value we got at the end of this lookup is - * not the expected one, we must restart lookup. - * We probably met an item that was moved to another chain. - */ - if (get_nulls_value(node) != slot) - goto begin; - - if (result) { - if (count != 1 || - unlikely(!atomic_inc_not_zero_hint(&result->sk_refcnt, 2))) - result = NULL; - else if (unlikely(!__udp_is_mcast_sock(net, result, - loc_port, loc_addr, - rmt_port, rmt_addr, - dif, hnum))) { - sock_put(result); - result = NULL; } } - rcu_read_unlock(); + return result; } @@ -2013,37 +1912,22 @@ static struct sock *__udp4_lib_demux_lookup(struct net *net, __be16 rmt_port, __be32 rmt_addr, int dif) { - struct sock *sk, *result; - struct hlist_nulls_node *node; unsigned short hnum = ntohs(loc_port); unsigned int hash2 = udp4_portaddr_hash(net, loc_addr, hnum); unsigned int slot2 = hash2 & udp_table.mask; struct udp_hslot *hslot2 = &udp_table.hash2[slot2]; INET_ADDR_COOKIE(acookie, rmt_addr, loc_addr); const __portpair ports = INET_COMBINED_PORTS(rmt_port, hnum); + struct sock *sk; - rcu_read_lock(); - result = NULL; - udp_portaddr_for_each_entry_rcu(sk, node, &hslot2->head) { - if (INET_MATCH(sk, net, acookie, - rmt_addr, loc_addr, ports, dif)) - result = sk; + udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) { + if (INET_MATCH(sk, net, acookie, rmt_addr, + loc_addr, ports, dif)) + return sk; /* Only check first socket in chain */ break; } - - if (result) { - if (unlikely(!atomic_inc_not_zero_hint(&result->sk_refcnt, 2))) - result = NULL; - else if (unlikely(!INET_MATCH(sk, net, acookie, - rmt_addr, loc_addr, - ports, dif))) { - sock_put(result); - result = NULL; - } - } - rcu_read_unlock(); - return result; + return NULL; } void udp_v4_early_demux(struct sk_buff *skb) @@ -2051,7 +1935,7 @@ void udp_v4_early_demux(struct sk_buff *skb) struct net *net = dev_net(skb->dev); const struct iphdr *iph; const struct udphdr *uh; - struct sock *sk; + struct sock *sk = NULL; struct dst_entry *dst; int dif = skb->dev->ifindex; int ours; @@ -2083,11 +1967,9 @@ void udp_v4_early_demux(struct sk_buff *skb) } else if (skb->pkt_type == PACKET_HOST) { sk = __udp4_lib_demux_lookup(net, uh->dest, iph->daddr, uh->source, iph->saddr, dif); - } else { - return; } - if (!sk) + if (!sk || !atomic_inc_not_zero_hint(&sk->sk_refcnt, 2)) return; skb->sk = sk; @@ -2387,14 +2269,13 @@ static struct sock *udp_get_first(struct seq_file *seq, int start) for (state->bucket = start; state->bucket <= state->udp_table->mask; ++state->bucket) { - struct hlist_nulls_node *node; struct udp_hslot *hslot = &state->udp_table->hash[state->bucket]; - if (hlist_nulls_empty(&hslot->head)) + if (hlist_empty(&hslot->head)) continue; spin_lock_bh(&hslot->lock); - sk_nulls_for_each(sk, node, &hslot->head) { + sk_for_each(sk, &hslot->head) { if (!net_eq(sock_net(sk), net)) continue; if (sk->sk_family == state->family) @@ -2413,7 +2294,7 @@ static struct sock *udp_get_next(struct seq_file *seq, struct sock *sk) struct net *net = seq_file_net(seq); do { - sk = sk_nulls_next(sk); + sk = sk_next(sk); } while (sk && (!net_eq(sock_net(sk), net) || sk->sk_family != state->family)); if (!sk) { @@ -2622,12 +2503,12 @@ void __init udp_table_init(struct udp_table *table, const char *name) table->hash2 = table->hash + (table->mask + 1); for (i = 0; i <= table->mask; i++) { - INIT_HLIST_NULLS_HEAD(&table->hash[i].head, i); + INIT_HLIST_HEAD(&table->hash[i].head); table->hash[i].count = 0; spin_lock_init(&table->hash[i].lock); } for (i = 0; i <= table->mask; i++) { - INIT_HLIST_NULLS_HEAD(&table->hash2[i].head, i); + INIT_HLIST_HEAD(&table->hash2[i].head); table->hash2[i].count = 0; spin_lock_init(&table->hash2[i].lock); } diff --git a/net/ipv4/udp_diag.c b/net/ipv4/udp_diag.c index df1966f3b6ec..3d5ccf4b1412 100644 --- a/net/ipv4/udp_diag.c +++ b/net/ipv4/udp_diag.c @@ -36,10 +36,11 @@ static int udp_dump_one(struct udp_table *tbl, struct sk_buff *in_skb, const struct inet_diag_req_v2 *req) { int err = -EINVAL; - struct sock *sk; + struct sock *sk = NULL; struct sk_buff *rep; struct net *net = sock_net(in_skb->sk); + rcu_read_lock(); if (req->sdiag_family == AF_INET) sk = __udp4_lib_lookup(net, req->id.idiag_src[0], req->id.idiag_sport, @@ -54,9 +55,9 @@ static int udp_dump_one(struct udp_table *tbl, struct sk_buff *in_skb, req->id.idiag_dport, req->id.idiag_if, tbl, NULL); #endif - else - goto out_nosk; - + if (sk && !atomic_inc_not_zero(&sk->sk_refcnt)) + sk = NULL; + rcu_read_unlock(); err = -ENOENT; if (!sk) goto out_nosk; @@ -96,24 +97,23 @@ static void udp_dump(struct udp_table *table, struct sk_buff *skb, struct netlink_callback *cb, const struct inet_diag_req_v2 *r, struct nlattr *bc) { - int num, s_num, slot, s_slot; struct net *net = sock_net(skb->sk); + int num, s_num, slot, s_slot; s_slot = cb->args[0]; num = s_num = cb->args[1]; for (slot = s_slot; slot <= table->mask; s_num = 0, slot++) { - struct sock *sk; - struct hlist_nulls_node *node; struct udp_hslot *hslot = &table->hash[slot]; + struct sock *sk; num = 0; - if (hlist_nulls_empty(&hslot->head)) + if (hlist_empty(&hslot->head)) continue; spin_lock_bh(&hslot->lock); - sk_nulls_for_each(sk, node, &hslot->head) { + sk_for_each(sk, &hslot->head) { struct inet_sock *inet = inet_sk(sk); if (!net_eq(sock_net(sk), net)) diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c index b772a7641fbd..78a7dfd12707 100644 --- a/net/ipv6/udp.c +++ b/net/ipv6/udp.c @@ -213,37 +213,28 @@ static struct sock *udp6_lib_lookup2(struct net *net, struct sk_buff *skb) { struct sock *sk, *result; - struct hlist_nulls_node *node; int score, badness, matches = 0, reuseport = 0; - bool select_ok = true; u32 hash = 0; -begin: result = NULL; badness = -1; - udp_portaddr_for_each_entry_rcu(sk, node, &hslot2->head) { + udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) { score = compute_score2(sk, net, saddr, sport, daddr, hnum, dif); if (score > badness) { - result = sk; - badness = score; reuseport = sk->sk_reuseport; if (reuseport) { hash = udp6_ehashfn(net, daddr, hnum, saddr, sport); - if (select_ok) { - struct sock *sk2; - sk2 = reuseport_select_sock(sk, hash, skb, + result = reuseport_select_sock(sk, hash, skb, sizeof(struct udphdr)); - if (sk2) { - result = sk2; - select_ok = false; - goto found; - } - } + if (result) + return result; matches = 1; } + result = sk; + badness = score; } else if (score == badness && reuseport) { matches++; if (reciprocal_scale(hash, matches) == 0) @@ -251,27 +242,10 @@ begin: hash = next_pseudo_random32(hash); } } - /* - * if the nulls value we got at the end of this lookup is - * not the expected one, we must restart lookup. - * We probably met an item that was moved to another chain. - */ - if (get_nulls_value(node) != slot2) - goto begin; - - if (result) { -found: - if (unlikely(!atomic_inc_not_zero_hint(&result->sk_refcnt, 2))) - result = NULL; - else if (unlikely(compute_score2(result, net, saddr, sport, - daddr, hnum, dif) < badness)) { - sock_put(result); - goto begin; - } - } return result; } +/* rcu_read_lock() must be held */ struct sock *__udp6_lib_lookup(struct net *net, const struct in6_addr *saddr, __be16 sport, const struct in6_addr *daddr, __be16 dport, @@ -279,15 +253,12 @@ struct sock *__udp6_lib_lookup(struct net *net, struct sk_buff *skb) { struct sock *sk, *result; - struct hlist_nulls_node *node; unsigned short hnum = ntohs(dport); unsigned int hash2, slot2, slot = udp_hashfn(net, hnum, udptable->mask); struct udp_hslot *hslot2, *hslot = &udptable->hash[slot]; int score, badness, matches = 0, reuseport = 0; - bool select_ok = true; u32 hash = 0; - rcu_read_lock(); if (hslot->count > 10) { hash2 = udp6_portaddr_hash(net, daddr, hnum); slot2 = hash2 & udptable->mask; @@ -309,34 +280,26 @@ struct sock *__udp6_lib_lookup(struct net *net, &in6addr_any, hnum, dif, hslot2, slot2, skb); } - rcu_read_unlock(); return result; } begin: result = NULL; badness = -1; - sk_nulls_for_each_rcu(sk, node, &hslot->head) { + sk_for_each_rcu(sk, &hslot->head) { score = compute_score(sk, net, hnum, saddr, sport, daddr, dport, dif); if (score > badness) { - result = sk; - badness = score; reuseport = sk->sk_reuseport; if (reuseport) { hash = udp6_ehashfn(net, daddr, hnum, saddr, sport); - if (select_ok) { - struct sock *sk2; - - sk2 = reuseport_select_sock(sk, hash, skb, + result = reuseport_select_sock(sk, hash, skb, sizeof(struct udphdr)); - if (sk2) { - result = sk2; - select_ok = false; - goto found; - } - } + if (result) + return result; matches = 1; } + result = sk; + badness = score; } else if (score == badness && reuseport) { matches++; if (reciprocal_scale(hash, matches) == 0) @@ -344,25 +307,6 @@ begin: hash = next_pseudo_random32(hash); } } - /* - * if the nulls value we got at the end of this lookup is - * not the expected one, we must restart lookup. - * We probably met an item that was moved to another chain. - */ - if (get_nulls_value(node) != slot) - goto begin; - - if (result) { -found: - if (unlikely(!atomic_inc_not_zero_hint(&result->sk_refcnt, 2))) - result = NULL; - else if (unlikely(compute_score(result, net, hnum, saddr, sport, - daddr, dport, dif) < badness)) { - sock_put(result); - goto begin; - } - } - rcu_read_unlock(); return result; } EXPORT_SYMBOL_GPL(__udp6_lib_lookup); @@ -382,12 +326,24 @@ static struct sock *__udp6_lib_lookup_skb(struct sk_buff *skb, udptable, skb); } +/* Must be called under rcu_read_lock(). + * Does increment socket refcount. + */ +#if IS_ENABLED(CONFIG_NETFILTER_XT_MATCH_SOCKET) || \ + IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TPROXY) struct sock *udp6_lib_lookup(struct net *net, const struct in6_addr *saddr, __be16 sport, const struct in6_addr *daddr, __be16 dport, int dif) { - return __udp6_lib_lookup(net, saddr, sport, daddr, dport, dif, &udp_table, NULL); + struct sock *sk; + + sk = __udp6_lib_lookup(net, saddr, sport, daddr, dport, + dif, &udp_table, NULL); + if (sk && !atomic_inc_not_zero(&sk->sk_refcnt)) + sk = NULL; + return sk; } EXPORT_SYMBOL_GPL(udp6_lib_lookup); +#endif /* * This should be easy, if there is something there we @@ -585,7 +541,7 @@ void __udp6_lib_err(struct sk_buff *skb, struct inet6_skb_parm *opt, sk->sk_err = err; sk->sk_error_report(sk); out: - sock_put(sk); + return; } static int __udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) @@ -747,33 +703,6 @@ static bool __udp_v6_is_mcast_sock(struct net *net, struct sock *sk, return true; } -static void flush_stack(struct sock **stack, unsigned int count, - struct sk_buff *skb, unsigned int final) -{ - struct sk_buff *skb1 = NULL; - struct sock *sk; - unsigned int i; - - for (i = 0; i < count; i++) { - sk = stack[i]; - if (likely(!skb1)) - skb1 = (i == final) ? skb : skb_clone(skb, GFP_ATOMIC); - if (!skb1) { - atomic_inc(&sk->sk_drops); - UDP6_INC_STATS_BH(sock_net(sk), UDP_MIB_RCVBUFERRORS, - IS_UDPLITE(sk)); - UDP6_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, - IS_UDPLITE(sk)); - } - - if (skb1 && udpv6_queue_rcv_skb(sk, skb1) <= 0) - skb1 = NULL; - sock_put(sk); - } - if (unlikely(skb1)) - kfree_skb(skb1); -} - static void udp6_csum_zero_error(struct sk_buff *skb) { /* RFC 2460 section 8.1 says that we SHOULD log @@ -792,15 +721,15 @@ static int __udp6_lib_mcast_deliver(struct net *net, struct sk_buff *skb, const struct in6_addr *saddr, const struct in6_addr *daddr, struct udp_table *udptable, int proto) { - struct sock *sk, *stack[256 / sizeof(struct sock *)]; + struct sock *sk, *first = NULL; const struct udphdr *uh = udp_hdr(skb); - struct hlist_nulls_node *node; unsigned short hnum = ntohs(uh->dest); struct udp_hslot *hslot = udp_hashslot(udptable, net, hnum); - int dif = inet6_iif(skb); - unsigned int count = 0, offset = offsetof(typeof(*sk), sk_nulls_node); + unsigned int offset = offsetof(typeof(*sk), sk_node); unsigned int hash2 = 0, hash2_any = 0, use_hash2 = (hslot->count > 10); - bool inner_flushed = false; + int dif = inet6_iif(skb); + struct hlist_node *node; + struct sk_buff *nskb; if (use_hash2) { hash2_any = udp6_portaddr_hash(net, &in6addr_any, hnum) & @@ -811,27 +740,32 @@ start_lookup: offset = offsetof(typeof(*sk), __sk_common.skc_portaddr_node); } - spin_lock(&hslot->lock); - sk_nulls_for_each_entry_offset(sk, node, &hslot->head, offset) { - if (__udp_v6_is_mcast_sock(net, sk, - uh->dest, daddr, - uh->source, saddr, - dif, hnum) && - /* If zero checksum and no_check is not on for - * the socket then skip it. - */ - (uh->check || udp_sk(sk)->no_check6_rx)) { - if (unlikely(count == ARRAY_SIZE(stack))) { - flush_stack(stack, count, skb, ~0); - inner_flushed = true; - count = 0; - } - stack[count++] = sk; - sock_hold(sk); + sk_for_each_entry_offset_rcu(sk, node, &hslot->head, offset) { + if (!__udp_v6_is_mcast_sock(net, sk, uh->dest, daddr, + uh->source, saddr, dif, hnum)) + continue; + /* If zero checksum and no_check is not on for + * the socket then skip it. + */ + if (!uh->check && !udp_sk(sk)->no_check6_rx) + continue; + if (!first) { + first = sk; + continue; + } + nskb = skb_clone(skb, GFP_ATOMIC); + if (unlikely(!nskb)) { + atomic_inc(&sk->sk_drops); + UDP6_INC_STATS_BH(net, UDP_MIB_RCVBUFERRORS, + IS_UDPLITE(sk)); + UDP6_INC_STATS_BH(net, UDP_MIB_INERRORS, + IS_UDPLITE(sk)); + continue; } - } - spin_unlock(&hslot->lock); + if (udpv6_queue_rcv_skb(sk, nskb) > 0) + consume_skb(nskb); + } /* Also lookup *:port if we are using hash2 and haven't done so yet. */ if (use_hash2 && hash2 != hash2_any) { @@ -839,13 +773,13 @@ start_lookup: goto start_lookup; } - if (count) { - flush_stack(stack, count, skb, count - 1); + if (first) { + if (udpv6_queue_rcv_skb(first, skb) > 0) + consume_skb(skb); } else { - if (!inner_flushed) - UDP6_INC_STATS_BH(net, UDP_MIB_IGNOREDMULTI, - proto == IPPROTO_UDPLITE); - consume_skb(skb); + kfree_skb(skb); + UDP6_INC_STATS_BH(net, UDP_MIB_IGNOREDMULTI, + proto == IPPROTO_UDPLITE); } return 0; } @@ -853,10 +787,10 @@ start_lookup: int __udp6_lib_rcv(struct sk_buff *skb, struct udp_table *udptable, int proto) { + const struct in6_addr *saddr, *daddr; struct net *net = dev_net(skb->dev); - struct sock *sk; struct udphdr *uh; - const struct in6_addr *saddr, *daddr; + struct sock *sk; u32 ulen = 0; if (!pskb_may_pull(skb, sizeof(struct udphdr))) @@ -910,7 +844,6 @@ int __udp6_lib_rcv(struct sk_buff *skb, struct udp_table *udptable, int ret; if (!uh->check && !udp_sk(sk)->no_check6_rx) { - sock_put(sk); udp6_csum_zero_error(skb); goto csum_error; } @@ -920,7 +853,6 @@ int __udp6_lib_rcv(struct sk_buff *skb, struct udp_table *udptable, ip6_compute_pseudo); ret = udpv6_queue_rcv_skb(sk, skb); - sock_put(sk); /* a return value > 0 means to resubmit the input */ if (ret > 0) -- 2.20.1