v4.19.13 snapshot.
diff --git a/kernel/bpf/sockmap.c b/kernel/bpf/sockmap.c
new file mode 100644
index 0000000..0a0f2ec
--- /dev/null
+++ b/kernel/bpf/sockmap.c
@@ -0,0 +1,2631 @@
+/* Copyright (c) 2017 Covalent IO, Inc. http://covalent.io
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ */
+
+/* A BPF sock_map is used to store sock objects. This is primarly used
+ * for doing socket redirect with BPF helper routines.
+ *
+ * A sock map may have BPF programs attached to it, currently a program
+ * used to parse packets and a program to provide a verdict and redirect
+ * decision on the packet are supported. Any programs attached to a sock
+ * map are inherited by sock objects when they are added to the map. If
+ * no BPF programs are attached the sock object may only be used for sock
+ * redirect.
+ *
+ * A sock object may be in multiple maps, but can only inherit a single
+ * parse or verdict program. If adding a sock object to a map would result
+ * in having multiple parsing programs the update will return an EBUSY error.
+ *
+ * For reference this program is similar to devmap used in XDP context
+ * reviewing these together may be useful. For an example please review
+ * ./samples/bpf/sockmap/.
+ */
+#include <linux/bpf.h>
+#include <net/sock.h>
+#include <linux/filter.h>
+#include <linux/errno.h>
+#include <linux/file.h>
+#include <linux/kernel.h>
+#include <linux/net.h>
+#include <linux/skbuff.h>
+#include <linux/workqueue.h>
+#include <linux/list.h>
+#include <linux/mm.h>
+#include <net/strparser.h>
+#include <net/tcp.h>
+#include <linux/ptr_ring.h>
+#include <net/inet_common.h>
+#include <linux/sched/signal.h>
+
+#define SOCK_CREATE_FLAG_MASK \
+ (BPF_F_NUMA_NODE | BPF_F_RDONLY | BPF_F_WRONLY)
+
+struct bpf_sock_progs {
+ struct bpf_prog *bpf_tx_msg;
+ struct bpf_prog *bpf_parse;
+ struct bpf_prog *bpf_verdict;
+};
+
+struct bpf_stab {
+ struct bpf_map map;
+ struct sock **sock_map;
+ struct bpf_sock_progs progs;
+ raw_spinlock_t lock;
+};
+
+struct bucket {
+ struct hlist_head head;
+ raw_spinlock_t lock;
+};
+
+struct bpf_htab {
+ struct bpf_map map;
+ struct bucket *buckets;
+ atomic_t count;
+ u32 n_buckets;
+ u32 elem_size;
+ struct bpf_sock_progs progs;
+ struct rcu_head rcu;
+};
+
+struct htab_elem {
+ struct rcu_head rcu;
+ struct hlist_node hash_node;
+ u32 hash;
+ struct sock *sk;
+ char key[0];
+};
+
+enum smap_psock_state {
+ SMAP_TX_RUNNING,
+};
+
+struct smap_psock_map_entry {
+ struct list_head list;
+ struct bpf_map *map;
+ struct sock **entry;
+ struct htab_elem __rcu *hash_link;
+};
+
+struct smap_psock {
+ struct rcu_head rcu;
+ refcount_t refcnt;
+
+ /* datapath variables */
+ struct sk_buff_head rxqueue;
+ bool strp_enabled;
+
+ /* datapath error path cache across tx work invocations */
+ int save_rem;
+ int save_off;
+ struct sk_buff *save_skb;
+
+ /* datapath variables for tx_msg ULP */
+ struct sock *sk_redir;
+ int apply_bytes;
+ int cork_bytes;
+ int sg_size;
+ int eval;
+ struct sk_msg_buff *cork;
+ struct list_head ingress;
+
+ struct strparser strp;
+ struct bpf_prog *bpf_tx_msg;
+ struct bpf_prog *bpf_parse;
+ struct bpf_prog *bpf_verdict;
+ struct list_head maps;
+ spinlock_t maps_lock;
+
+ /* Back reference used when sock callback trigger sockmap operations */
+ struct sock *sock;
+ unsigned long state;
+
+ struct work_struct tx_work;
+ struct work_struct gc_work;
+
+ struct proto *sk_proto;
+ void (*save_unhash)(struct sock *sk);
+ void (*save_close)(struct sock *sk, long timeout);
+ void (*save_data_ready)(struct sock *sk);
+ void (*save_write_space)(struct sock *sk);
+};
+
+static void smap_release_sock(struct smap_psock *psock, struct sock *sock);
+static int bpf_tcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
+ int nonblock, int flags, int *addr_len);
+static int bpf_tcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t size);
+static int bpf_tcp_sendpage(struct sock *sk, struct page *page,
+ int offset, size_t size, int flags);
+static void bpf_tcp_unhash(struct sock *sk);
+static void bpf_tcp_close(struct sock *sk, long timeout);
+
+static inline struct smap_psock *smap_psock_sk(const struct sock *sk)
+{
+ return rcu_dereference_sk_user_data(sk);
+}
+
+static bool bpf_tcp_stream_read(const struct sock *sk)
+{
+ struct smap_psock *psock;
+ bool empty = true;
+
+ rcu_read_lock();
+ psock = smap_psock_sk(sk);
+ if (unlikely(!psock))
+ goto out;
+ empty = list_empty(&psock->ingress);
+out:
+ rcu_read_unlock();
+ return !empty;
+}
+
+enum {
+ SOCKMAP_IPV4,
+ SOCKMAP_IPV6,
+ SOCKMAP_NUM_PROTS,
+};
+
+enum {
+ SOCKMAP_BASE,
+ SOCKMAP_TX,
+ SOCKMAP_NUM_CONFIGS,
+};
+
+static struct proto *saved_tcpv6_prot __read_mostly;
+static DEFINE_SPINLOCK(tcpv6_prot_lock);
+static struct proto bpf_tcp_prots[SOCKMAP_NUM_PROTS][SOCKMAP_NUM_CONFIGS];
+static void build_protos(struct proto prot[SOCKMAP_NUM_CONFIGS],
+ struct proto *base)
+{
+ prot[SOCKMAP_BASE] = *base;
+ prot[SOCKMAP_BASE].unhash = bpf_tcp_unhash;
+ prot[SOCKMAP_BASE].close = bpf_tcp_close;
+ prot[SOCKMAP_BASE].recvmsg = bpf_tcp_recvmsg;
+ prot[SOCKMAP_BASE].stream_memory_read = bpf_tcp_stream_read;
+
+ prot[SOCKMAP_TX] = prot[SOCKMAP_BASE];
+ prot[SOCKMAP_TX].sendmsg = bpf_tcp_sendmsg;
+ prot[SOCKMAP_TX].sendpage = bpf_tcp_sendpage;
+}
+
+static void update_sk_prot(struct sock *sk, struct smap_psock *psock)
+{
+ int family = sk->sk_family == AF_INET6 ? SOCKMAP_IPV6 : SOCKMAP_IPV4;
+ int conf = psock->bpf_tx_msg ? SOCKMAP_TX : SOCKMAP_BASE;
+
+ sk->sk_prot = &bpf_tcp_prots[family][conf];
+}
+
+static int bpf_tcp_init(struct sock *sk)
+{
+ struct smap_psock *psock;
+
+ rcu_read_lock();
+ psock = smap_psock_sk(sk);
+ if (unlikely(!psock)) {
+ rcu_read_unlock();
+ return -EINVAL;
+ }
+
+ if (unlikely(psock->sk_proto)) {
+ rcu_read_unlock();
+ return -EBUSY;
+ }
+
+ psock->save_unhash = sk->sk_prot->unhash;
+ psock->save_close = sk->sk_prot->close;
+ psock->sk_proto = sk->sk_prot;
+
+ /* Build IPv6 sockmap whenever the address of tcpv6_prot changes */
+ if (sk->sk_family == AF_INET6 &&
+ unlikely(sk->sk_prot != smp_load_acquire(&saved_tcpv6_prot))) {
+ spin_lock_bh(&tcpv6_prot_lock);
+ if (likely(sk->sk_prot != saved_tcpv6_prot)) {
+ build_protos(bpf_tcp_prots[SOCKMAP_IPV6], sk->sk_prot);
+ smp_store_release(&saved_tcpv6_prot, sk->sk_prot);
+ }
+ spin_unlock_bh(&tcpv6_prot_lock);
+ }
+ update_sk_prot(sk, psock);
+ rcu_read_unlock();
+ return 0;
+}
+
+static void smap_release_sock(struct smap_psock *psock, struct sock *sock);
+static int free_start_sg(struct sock *sk, struct sk_msg_buff *md, bool charge);
+
+static void bpf_tcp_release(struct sock *sk)
+{
+ struct smap_psock *psock;
+
+ rcu_read_lock();
+ psock = smap_psock_sk(sk);
+ if (unlikely(!psock))
+ goto out;
+
+ if (psock->cork) {
+ free_start_sg(psock->sock, psock->cork, true);
+ kfree(psock->cork);
+ psock->cork = NULL;
+ }
+
+ if (psock->sk_proto) {
+ sk->sk_prot = psock->sk_proto;
+ psock->sk_proto = NULL;
+ }
+out:
+ rcu_read_unlock();
+}
+
+static struct htab_elem *lookup_elem_raw(struct hlist_head *head,
+ u32 hash, void *key, u32 key_size)
+{
+ struct htab_elem *l;
+
+ hlist_for_each_entry_rcu(l, head, hash_node) {
+ if (l->hash == hash && !memcmp(&l->key, key, key_size))
+ return l;
+ }
+
+ return NULL;
+}
+
+static inline struct bucket *__select_bucket(struct bpf_htab *htab, u32 hash)
+{
+ return &htab->buckets[hash & (htab->n_buckets - 1)];
+}
+
+static inline struct hlist_head *select_bucket(struct bpf_htab *htab, u32 hash)
+{
+ return &__select_bucket(htab, hash)->head;
+}
+
+static void free_htab_elem(struct bpf_htab *htab, struct htab_elem *l)
+{
+ atomic_dec(&htab->count);
+ kfree_rcu(l, rcu);
+}
+
+static struct smap_psock_map_entry *psock_map_pop(struct sock *sk,
+ struct smap_psock *psock)
+{
+ struct smap_psock_map_entry *e;
+
+ spin_lock_bh(&psock->maps_lock);
+ e = list_first_entry_or_null(&psock->maps,
+ struct smap_psock_map_entry,
+ list);
+ if (e)
+ list_del(&e->list);
+ spin_unlock_bh(&psock->maps_lock);
+ return e;
+}
+
+static void bpf_tcp_remove(struct sock *sk, struct smap_psock *psock)
+{
+ struct smap_psock_map_entry *e;
+ struct sk_msg_buff *md, *mtmp;
+ struct sock *osk;
+
+ if (psock->cork) {
+ free_start_sg(psock->sock, psock->cork, true);
+ kfree(psock->cork);
+ psock->cork = NULL;
+ }
+
+ list_for_each_entry_safe(md, mtmp, &psock->ingress, list) {
+ list_del(&md->list);
+ free_start_sg(psock->sock, md, true);
+ kfree(md);
+ }
+
+ e = psock_map_pop(sk, psock);
+ while (e) {
+ if (e->entry) {
+ struct bpf_stab *stab = container_of(e->map, struct bpf_stab, map);
+
+ raw_spin_lock_bh(&stab->lock);
+ osk = *e->entry;
+ if (osk == sk) {
+ *e->entry = NULL;
+ smap_release_sock(psock, sk);
+ }
+ raw_spin_unlock_bh(&stab->lock);
+ } else {
+ struct htab_elem *link = rcu_dereference(e->hash_link);
+ struct bpf_htab *htab = container_of(e->map, struct bpf_htab, map);
+ struct hlist_head *head;
+ struct htab_elem *l;
+ struct bucket *b;
+
+ b = __select_bucket(htab, link->hash);
+ head = &b->head;
+ raw_spin_lock_bh(&b->lock);
+ l = lookup_elem_raw(head,
+ link->hash, link->key,
+ htab->map.key_size);
+ /* If another thread deleted this object skip deletion.
+ * The refcnt on psock may or may not be zero.
+ */
+ if (l && l == link) {
+ hlist_del_rcu(&link->hash_node);
+ smap_release_sock(psock, link->sk);
+ free_htab_elem(htab, link);
+ }
+ raw_spin_unlock_bh(&b->lock);
+ }
+ kfree(e);
+ e = psock_map_pop(sk, psock);
+ }
+}
+
+static void bpf_tcp_unhash(struct sock *sk)
+{
+ void (*unhash_fun)(struct sock *sk);
+ struct smap_psock *psock;
+
+ rcu_read_lock();
+ psock = smap_psock_sk(sk);
+ if (unlikely(!psock)) {
+ rcu_read_unlock();
+ if (sk->sk_prot->unhash)
+ sk->sk_prot->unhash(sk);
+ return;
+ }
+ unhash_fun = psock->save_unhash;
+ bpf_tcp_remove(sk, psock);
+ rcu_read_unlock();
+ unhash_fun(sk);
+}
+
+static void bpf_tcp_close(struct sock *sk, long timeout)
+{
+ void (*close_fun)(struct sock *sk, long timeout);
+ struct smap_psock *psock;
+
+ lock_sock(sk);
+ rcu_read_lock();
+ psock = smap_psock_sk(sk);
+ if (unlikely(!psock)) {
+ rcu_read_unlock();
+ release_sock(sk);
+ return sk->sk_prot->close(sk, timeout);
+ }
+ close_fun = psock->save_close;
+ bpf_tcp_remove(sk, psock);
+ rcu_read_unlock();
+ release_sock(sk);
+ close_fun(sk, timeout);
+}
+
+enum __sk_action {
+ __SK_DROP = 0,
+ __SK_PASS,
+ __SK_REDIRECT,
+ __SK_NONE,
+};
+
+static struct tcp_ulp_ops bpf_tcp_ulp_ops __read_mostly = {
+ .name = "bpf_tcp",
+ .uid = TCP_ULP_BPF,
+ .user_visible = false,
+ .owner = NULL,
+ .init = bpf_tcp_init,
+ .release = bpf_tcp_release,
+};
+
+static int memcopy_from_iter(struct sock *sk,
+ struct sk_msg_buff *md,
+ struct iov_iter *from, int bytes)
+{
+ struct scatterlist *sg = md->sg_data;
+ int i = md->sg_curr, rc = -ENOSPC;
+
+ do {
+ int copy;
+ char *to;
+
+ if (md->sg_copybreak >= sg[i].length) {
+ md->sg_copybreak = 0;
+
+ if (++i == MAX_SKB_FRAGS)
+ i = 0;
+
+ if (i == md->sg_end)
+ break;
+ }
+
+ copy = sg[i].length - md->sg_copybreak;
+ to = sg_virt(&sg[i]) + md->sg_copybreak;
+ md->sg_copybreak += copy;
+
+ if (sk->sk_route_caps & NETIF_F_NOCACHE_COPY)
+ rc = copy_from_iter_nocache(to, copy, from);
+ else
+ rc = copy_from_iter(to, copy, from);
+
+ if (rc != copy) {
+ rc = -EFAULT;
+ goto out;
+ }
+
+ bytes -= copy;
+ if (!bytes)
+ break;
+
+ md->sg_copybreak = 0;
+ if (++i == MAX_SKB_FRAGS)
+ i = 0;
+ } while (i != md->sg_end);
+out:
+ md->sg_curr = i;
+ return rc;
+}
+
+static int bpf_tcp_push(struct sock *sk, int apply_bytes,
+ struct sk_msg_buff *md,
+ int flags, bool uncharge)
+{
+ bool apply = apply_bytes;
+ struct scatterlist *sg;
+ int offset, ret = 0;
+ struct page *p;
+ size_t size;
+
+ while (1) {
+ sg = md->sg_data + md->sg_start;
+ size = (apply && apply_bytes < sg->length) ?
+ apply_bytes : sg->length;
+ offset = sg->offset;
+
+ tcp_rate_check_app_limited(sk);
+ p = sg_page(sg);
+retry:
+ ret = do_tcp_sendpages(sk, p, offset, size, flags);
+ if (ret != size) {
+ if (ret > 0) {
+ if (apply)
+ apply_bytes -= ret;
+
+ sg->offset += ret;
+ sg->length -= ret;
+ size -= ret;
+ offset += ret;
+ if (uncharge)
+ sk_mem_uncharge(sk, ret);
+ goto retry;
+ }
+
+ return ret;
+ }
+
+ if (apply)
+ apply_bytes -= ret;
+ sg->offset += ret;
+ sg->length -= ret;
+ if (uncharge)
+ sk_mem_uncharge(sk, ret);
+
+ if (!sg->length) {
+ put_page(p);
+ md->sg_start++;
+ if (md->sg_start == MAX_SKB_FRAGS)
+ md->sg_start = 0;
+ sg_init_table(sg, 1);
+
+ if (md->sg_start == md->sg_end)
+ break;
+ }
+
+ if (apply && !apply_bytes)
+ break;
+ }
+ return 0;
+}
+
+static inline void bpf_compute_data_pointers_sg(struct sk_msg_buff *md)
+{
+ struct scatterlist *sg = md->sg_data + md->sg_start;
+
+ if (md->sg_copy[md->sg_start]) {
+ md->data = md->data_end = 0;
+ } else {
+ md->data = sg_virt(sg);
+ md->data_end = md->data + sg->length;
+ }
+}
+
+static void return_mem_sg(struct sock *sk, int bytes, struct sk_msg_buff *md)
+{
+ struct scatterlist *sg = md->sg_data;
+ int i = md->sg_start;
+
+ do {
+ int uncharge = (bytes < sg[i].length) ? bytes : sg[i].length;
+
+ sk_mem_uncharge(sk, uncharge);
+ bytes -= uncharge;
+ if (!bytes)
+ break;
+ i++;
+ if (i == MAX_SKB_FRAGS)
+ i = 0;
+ } while (i != md->sg_end);
+}
+
+static void free_bytes_sg(struct sock *sk, int bytes,
+ struct sk_msg_buff *md, bool charge)
+{
+ struct scatterlist *sg = md->sg_data;
+ int i = md->sg_start, free;
+
+ while (bytes && sg[i].length) {
+ free = sg[i].length;
+ if (bytes < free) {
+ sg[i].length -= bytes;
+ sg[i].offset += bytes;
+ if (charge)
+ sk_mem_uncharge(sk, bytes);
+ break;
+ }
+
+ if (charge)
+ sk_mem_uncharge(sk, sg[i].length);
+ put_page(sg_page(&sg[i]));
+ bytes -= sg[i].length;
+ sg[i].length = 0;
+ sg[i].page_link = 0;
+ sg[i].offset = 0;
+ i++;
+
+ if (i == MAX_SKB_FRAGS)
+ i = 0;
+ }
+ md->sg_start = i;
+}
+
+static int free_sg(struct sock *sk, int start,
+ struct sk_msg_buff *md, bool charge)
+{
+ struct scatterlist *sg = md->sg_data;
+ int i = start, free = 0;
+
+ while (sg[i].length) {
+ free += sg[i].length;
+ if (charge)
+ sk_mem_uncharge(sk, sg[i].length);
+ if (!md->skb)
+ put_page(sg_page(&sg[i]));
+ sg[i].length = 0;
+ sg[i].page_link = 0;
+ sg[i].offset = 0;
+ i++;
+
+ if (i == MAX_SKB_FRAGS)
+ i = 0;
+ }
+ if (md->skb)
+ consume_skb(md->skb);
+
+ return free;
+}
+
+static int free_start_sg(struct sock *sk, struct sk_msg_buff *md, bool charge)
+{
+ int free = free_sg(sk, md->sg_start, md, charge);
+
+ md->sg_start = md->sg_end;
+ return free;
+}
+
+static int free_curr_sg(struct sock *sk, struct sk_msg_buff *md)
+{
+ return free_sg(sk, md->sg_curr, md, true);
+}
+
+static int bpf_map_msg_verdict(int _rc, struct sk_msg_buff *md)
+{
+ return ((_rc == SK_PASS) ?
+ (md->sk_redir ? __SK_REDIRECT : __SK_PASS) :
+ __SK_DROP);
+}
+
+static unsigned int smap_do_tx_msg(struct sock *sk,
+ struct smap_psock *psock,
+ struct sk_msg_buff *md)
+{
+ struct bpf_prog *prog;
+ unsigned int rc, _rc;
+
+ preempt_disable();
+ rcu_read_lock();
+
+ /* If the policy was removed mid-send then default to 'accept' */
+ prog = READ_ONCE(psock->bpf_tx_msg);
+ if (unlikely(!prog)) {
+ _rc = SK_PASS;
+ goto verdict;
+ }
+
+ bpf_compute_data_pointers_sg(md);
+ md->sk = sk;
+ rc = (*prog->bpf_func)(md, prog->insnsi);
+ psock->apply_bytes = md->apply_bytes;
+
+ /* Moving return codes from UAPI namespace into internal namespace */
+ _rc = bpf_map_msg_verdict(rc, md);
+
+ /* The psock has a refcount on the sock but not on the map and because
+ * we need to drop rcu read lock here its possible the map could be
+ * removed between here and when we need it to execute the sock
+ * redirect. So do the map lookup now for future use.
+ */
+ if (_rc == __SK_REDIRECT) {
+ if (psock->sk_redir)
+ sock_put(psock->sk_redir);
+ psock->sk_redir = do_msg_redirect_map(md);
+ if (!psock->sk_redir) {
+ _rc = __SK_DROP;
+ goto verdict;
+ }
+ sock_hold(psock->sk_redir);
+ }
+verdict:
+ rcu_read_unlock();
+ preempt_enable();
+
+ return _rc;
+}
+
+static int bpf_tcp_ingress(struct sock *sk, int apply_bytes,
+ struct smap_psock *psock,
+ struct sk_msg_buff *md, int flags)
+{
+ bool apply = apply_bytes;
+ size_t size, copied = 0;
+ struct sk_msg_buff *r;
+ int err = 0, i;
+
+ r = kzalloc(sizeof(struct sk_msg_buff), __GFP_NOWARN | GFP_KERNEL);
+ if (unlikely(!r))
+ return -ENOMEM;
+
+ lock_sock(sk);
+ r->sg_start = md->sg_start;
+ i = md->sg_start;
+
+ do {
+ size = (apply && apply_bytes < md->sg_data[i].length) ?
+ apply_bytes : md->sg_data[i].length;
+
+ if (!sk_wmem_schedule(sk, size)) {
+ if (!copied)
+ err = -ENOMEM;
+ break;
+ }
+
+ sk_mem_charge(sk, size);
+ r->sg_data[i] = md->sg_data[i];
+ r->sg_data[i].length = size;
+ md->sg_data[i].length -= size;
+ md->sg_data[i].offset += size;
+ copied += size;
+
+ if (md->sg_data[i].length) {
+ get_page(sg_page(&r->sg_data[i]));
+ r->sg_end = (i + 1) == MAX_SKB_FRAGS ? 0 : i + 1;
+ } else {
+ i++;
+ if (i == MAX_SKB_FRAGS)
+ i = 0;
+ r->sg_end = i;
+ }
+
+ if (apply) {
+ apply_bytes -= size;
+ if (!apply_bytes)
+ break;
+ }
+ } while (i != md->sg_end);
+
+ md->sg_start = i;
+
+ if (!err) {
+ list_add_tail(&r->list, &psock->ingress);
+ sk->sk_data_ready(sk);
+ } else {
+ free_start_sg(sk, r, true);
+ kfree(r);
+ }
+
+ release_sock(sk);
+ return err;
+}
+
+static int bpf_tcp_sendmsg_do_redirect(struct sock *sk, int send,
+ struct sk_msg_buff *md,
+ int flags)
+{
+ bool ingress = !!(md->flags & BPF_F_INGRESS);
+ struct smap_psock *psock;
+ int err = 0;
+
+ rcu_read_lock();
+ psock = smap_psock_sk(sk);
+ if (unlikely(!psock))
+ goto out_rcu;
+
+ if (!refcount_inc_not_zero(&psock->refcnt))
+ goto out_rcu;
+
+ rcu_read_unlock();
+
+ if (ingress) {
+ err = bpf_tcp_ingress(sk, send, psock, md, flags);
+ } else {
+ lock_sock(sk);
+ err = bpf_tcp_push(sk, send, md, flags, false);
+ release_sock(sk);
+ }
+ smap_release_sock(psock, sk);
+ return err;
+out_rcu:
+ rcu_read_unlock();
+ return 0;
+}
+
+static inline void bpf_md_init(struct smap_psock *psock)
+{
+ if (!psock->apply_bytes) {
+ psock->eval = __SK_NONE;
+ if (psock->sk_redir) {
+ sock_put(psock->sk_redir);
+ psock->sk_redir = NULL;
+ }
+ }
+}
+
+static void apply_bytes_dec(struct smap_psock *psock, int i)
+{
+ if (psock->apply_bytes) {
+ if (psock->apply_bytes < i)
+ psock->apply_bytes = 0;
+ else
+ psock->apply_bytes -= i;
+ }
+}
+
+static int bpf_exec_tx_verdict(struct smap_psock *psock,
+ struct sk_msg_buff *m,
+ struct sock *sk,
+ int *copied, int flags)
+{
+ bool cork = false, enospc = (m->sg_start == m->sg_end);
+ struct sock *redir;
+ int err = 0;
+ int send;
+
+more_data:
+ if (psock->eval == __SK_NONE)
+ psock->eval = smap_do_tx_msg(sk, psock, m);
+
+ if (m->cork_bytes &&
+ m->cork_bytes > psock->sg_size && !enospc) {
+ psock->cork_bytes = m->cork_bytes - psock->sg_size;
+ if (!psock->cork) {
+ psock->cork = kcalloc(1,
+ sizeof(struct sk_msg_buff),
+ GFP_ATOMIC | __GFP_NOWARN);
+
+ if (!psock->cork) {
+ err = -ENOMEM;
+ goto out_err;
+ }
+ }
+ memcpy(psock->cork, m, sizeof(*m));
+ goto out_err;
+ }
+
+ send = psock->sg_size;
+ if (psock->apply_bytes && psock->apply_bytes < send)
+ send = psock->apply_bytes;
+
+ switch (psock->eval) {
+ case __SK_PASS:
+ err = bpf_tcp_push(sk, send, m, flags, true);
+ if (unlikely(err)) {
+ *copied -= free_start_sg(sk, m, true);
+ break;
+ }
+
+ apply_bytes_dec(psock, send);
+ psock->sg_size -= send;
+ break;
+ case __SK_REDIRECT:
+ redir = psock->sk_redir;
+ apply_bytes_dec(psock, send);
+
+ if (psock->cork) {
+ cork = true;
+ psock->cork = NULL;
+ }
+
+ return_mem_sg(sk, send, m);
+ release_sock(sk);
+
+ err = bpf_tcp_sendmsg_do_redirect(redir, send, m, flags);
+ lock_sock(sk);
+
+ if (unlikely(err < 0)) {
+ int free = free_start_sg(sk, m, false);
+
+ psock->sg_size = 0;
+ if (!cork)
+ *copied -= free;
+ } else {
+ psock->sg_size -= send;
+ }
+
+ if (cork) {
+ free_start_sg(sk, m, true);
+ psock->sg_size = 0;
+ kfree(m);
+ m = NULL;
+ err = 0;
+ }
+ break;
+ case __SK_DROP:
+ default:
+ free_bytes_sg(sk, send, m, true);
+ apply_bytes_dec(psock, send);
+ *copied -= send;
+ psock->sg_size -= send;
+ err = -EACCES;
+ break;
+ }
+
+ if (likely(!err)) {
+ bpf_md_init(psock);
+ if (m &&
+ m->sg_data[m->sg_start].page_link &&
+ m->sg_data[m->sg_start].length)
+ goto more_data;
+ }
+
+out_err:
+ return err;
+}
+
+static int bpf_wait_data(struct sock *sk,
+ struct smap_psock *psk, int flags,
+ long timeo, int *err)
+{
+ int rc;
+
+ DEFINE_WAIT_FUNC(wait, woken_wake_function);
+
+ add_wait_queue(sk_sleep(sk), &wait);
+ sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
+ rc = sk_wait_event(sk, &timeo,
+ !list_empty(&psk->ingress) ||
+ !skb_queue_empty(&sk->sk_receive_queue),
+ &wait);
+ sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
+ remove_wait_queue(sk_sleep(sk), &wait);
+
+ return rc;
+}
+
+static int bpf_tcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
+ int nonblock, int flags, int *addr_len)
+{
+ struct iov_iter *iter = &msg->msg_iter;
+ struct smap_psock *psock;
+ int copied = 0;
+
+ if (unlikely(flags & MSG_ERRQUEUE))
+ return inet_recv_error(sk, msg, len, addr_len);
+ if (!skb_queue_empty(&sk->sk_receive_queue))
+ return tcp_recvmsg(sk, msg, len, nonblock, flags, addr_len);
+
+ rcu_read_lock();
+ psock = smap_psock_sk(sk);
+ if (unlikely(!psock))
+ goto out;
+
+ if (unlikely(!refcount_inc_not_zero(&psock->refcnt)))
+ goto out;
+ rcu_read_unlock();
+
+ lock_sock(sk);
+bytes_ready:
+ while (copied != len) {
+ struct scatterlist *sg;
+ struct sk_msg_buff *md;
+ int i;
+
+ md = list_first_entry_or_null(&psock->ingress,
+ struct sk_msg_buff, list);
+ if (unlikely(!md))
+ break;
+ i = md->sg_start;
+ do {
+ struct page *page;
+ int n, copy;
+
+ sg = &md->sg_data[i];
+ copy = sg->length;
+ page = sg_page(sg);
+
+ if (copied + copy > len)
+ copy = len - copied;
+
+ n = copy_page_to_iter(page, sg->offset, copy, iter);
+ if (n != copy) {
+ md->sg_start = i;
+ release_sock(sk);
+ smap_release_sock(psock, sk);
+ return -EFAULT;
+ }
+
+ copied += copy;
+ sg->offset += copy;
+ sg->length -= copy;
+ sk_mem_uncharge(sk, copy);
+
+ if (!sg->length) {
+ i++;
+ if (i == MAX_SKB_FRAGS)
+ i = 0;
+ if (!md->skb)
+ put_page(page);
+ }
+ if (copied == len)
+ break;
+ } while (i != md->sg_end);
+ md->sg_start = i;
+
+ if (!sg->length && md->sg_start == md->sg_end) {
+ list_del(&md->list);
+ if (md->skb)
+ consume_skb(md->skb);
+ kfree(md);
+ }
+ }
+
+ if (!copied) {
+ long timeo;
+ int data;
+ int err = 0;
+
+ timeo = sock_rcvtimeo(sk, nonblock);
+ data = bpf_wait_data(sk, psock, flags, timeo, &err);
+
+ if (data) {
+ if (!skb_queue_empty(&sk->sk_receive_queue)) {
+ release_sock(sk);
+ smap_release_sock(psock, sk);
+ copied = tcp_recvmsg(sk, msg, len, nonblock, flags, addr_len);
+ return copied;
+ }
+ goto bytes_ready;
+ }
+
+ if (err)
+ copied = err;
+ }
+
+ release_sock(sk);
+ smap_release_sock(psock, sk);
+ return copied;
+out:
+ rcu_read_unlock();
+ return tcp_recvmsg(sk, msg, len, nonblock, flags, addr_len);
+}
+
+
+static int bpf_tcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)
+{
+ int flags = msg->msg_flags | MSG_NO_SHARED_FRAGS;
+ struct sk_msg_buff md = {0};
+ unsigned int sg_copy = 0;
+ struct smap_psock *psock;
+ int copied = 0, err = 0;
+ struct scatterlist *sg;
+ long timeo;
+
+ /* Its possible a sock event or user removed the psock _but_ the ops
+ * have not been reprogrammed yet so we get here. In this case fallback
+ * to tcp_sendmsg. Note this only works because we _only_ ever allow
+ * a single ULP there is no hierarchy here.
+ */
+ rcu_read_lock();
+ psock = smap_psock_sk(sk);
+ if (unlikely(!psock)) {
+ rcu_read_unlock();
+ return tcp_sendmsg(sk, msg, size);
+ }
+
+ /* Increment the psock refcnt to ensure its not released while sending a
+ * message. Required because sk lookup and bpf programs are used in
+ * separate rcu critical sections. Its OK if we lose the map entry
+ * but we can't lose the sock reference.
+ */
+ if (!refcount_inc_not_zero(&psock->refcnt)) {
+ rcu_read_unlock();
+ return tcp_sendmsg(sk, msg, size);
+ }
+
+ sg = md.sg_data;
+ sg_init_marker(sg, MAX_SKB_FRAGS);
+ rcu_read_unlock();
+
+ lock_sock(sk);
+ timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
+
+ while (msg_data_left(msg)) {
+ struct sk_msg_buff *m = NULL;
+ bool enospc = false;
+ int copy;
+
+ if (sk->sk_err) {
+ err = -sk->sk_err;
+ goto out_err;
+ }
+
+ copy = msg_data_left(msg);
+ if (!sk_stream_memory_free(sk))
+ goto wait_for_sndbuf;
+
+ m = psock->cork_bytes ? psock->cork : &md;
+ m->sg_curr = m->sg_copybreak ? m->sg_curr : m->sg_end;
+ err = sk_alloc_sg(sk, copy, m->sg_data,
+ m->sg_start, &m->sg_end, &sg_copy,
+ m->sg_end - 1);
+ if (err) {
+ if (err != -ENOSPC)
+ goto wait_for_memory;
+ enospc = true;
+ copy = sg_copy;
+ }
+
+ err = memcopy_from_iter(sk, m, &msg->msg_iter, copy);
+ if (err < 0) {
+ free_curr_sg(sk, m);
+ goto out_err;
+ }
+
+ psock->sg_size += copy;
+ copied += copy;
+ sg_copy = 0;
+
+ /* When bytes are being corked skip running BPF program and
+ * applying verdict unless there is no more buffer space. In
+ * the ENOSPC case simply run BPF prorgram with currently
+ * accumulated data. We don't have much choice at this point
+ * we could try extending the page frags or chaining complex
+ * frags but even in these cases _eventually_ we will hit an
+ * OOM scenario. More complex recovery schemes may be
+ * implemented in the future, but BPF programs must handle
+ * the case where apply_cork requests are not honored. The
+ * canonical method to verify this is to check data length.
+ */
+ if (psock->cork_bytes) {
+ if (copy > psock->cork_bytes)
+ psock->cork_bytes = 0;
+ else
+ psock->cork_bytes -= copy;
+
+ if (psock->cork_bytes && !enospc)
+ goto out_cork;
+
+ /* All cork bytes accounted for re-run filter */
+ psock->eval = __SK_NONE;
+ psock->cork_bytes = 0;
+ }
+
+ err = bpf_exec_tx_verdict(psock, m, sk, &copied, flags);
+ if (unlikely(err < 0))
+ goto out_err;
+ continue;
+wait_for_sndbuf:
+ set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
+wait_for_memory:
+ err = sk_stream_wait_memory(sk, &timeo);
+ if (err) {
+ if (m && m != psock->cork)
+ free_start_sg(sk, m, true);
+ goto out_err;
+ }
+ }
+out_err:
+ if (err < 0)
+ err = sk_stream_error(sk, msg->msg_flags, err);
+out_cork:
+ release_sock(sk);
+ smap_release_sock(psock, sk);
+ return copied ? copied : err;
+}
+
+static int bpf_tcp_sendpage(struct sock *sk, struct page *page,
+ int offset, size_t size, int flags)
+{
+ struct sk_msg_buff md = {0}, *m = NULL;
+ int err = 0, copied = 0;
+ struct smap_psock *psock;
+ struct scatterlist *sg;
+ bool enospc = false;
+
+ rcu_read_lock();
+ psock = smap_psock_sk(sk);
+ if (unlikely(!psock))
+ goto accept;
+
+ if (!refcount_inc_not_zero(&psock->refcnt))
+ goto accept;
+ rcu_read_unlock();
+
+ lock_sock(sk);
+
+ if (psock->cork_bytes) {
+ m = psock->cork;
+ sg = &m->sg_data[m->sg_end];
+ } else {
+ m = &md;
+ sg = m->sg_data;
+ sg_init_marker(sg, MAX_SKB_FRAGS);
+ }
+
+ /* Catch case where ring is full and sendpage is stalled. */
+ if (unlikely(m->sg_end == m->sg_start &&
+ m->sg_data[m->sg_end].length))
+ goto out_err;
+
+ psock->sg_size += size;
+ sg_set_page(sg, page, size, offset);
+ get_page(page);
+ m->sg_copy[m->sg_end] = true;
+ sk_mem_charge(sk, size);
+ m->sg_end++;
+ copied = size;
+
+ if (m->sg_end == MAX_SKB_FRAGS)
+ m->sg_end = 0;
+
+ if (m->sg_end == m->sg_start)
+ enospc = true;
+
+ if (psock->cork_bytes) {
+ if (size > psock->cork_bytes)
+ psock->cork_bytes = 0;
+ else
+ psock->cork_bytes -= size;
+
+ if (psock->cork_bytes && !enospc)
+ goto out_err;
+
+ /* All cork bytes accounted for re-run filter */
+ psock->eval = __SK_NONE;
+ psock->cork_bytes = 0;
+ }
+
+ err = bpf_exec_tx_verdict(psock, m, sk, &copied, flags);
+out_err:
+ release_sock(sk);
+ smap_release_sock(psock, sk);
+ return copied ? copied : err;
+accept:
+ rcu_read_unlock();
+ return tcp_sendpage(sk, page, offset, size, flags);
+}
+
+static void bpf_tcp_msg_add(struct smap_psock *psock,
+ struct sock *sk,
+ struct bpf_prog *tx_msg)
+{
+ struct bpf_prog *orig_tx_msg;
+
+ orig_tx_msg = xchg(&psock->bpf_tx_msg, tx_msg);
+ if (orig_tx_msg)
+ bpf_prog_put(orig_tx_msg);
+}
+
+static int bpf_tcp_ulp_register(void)
+{
+ build_protos(bpf_tcp_prots[SOCKMAP_IPV4], &tcp_prot);
+ /* Once BPF TX ULP is registered it is never unregistered. It
+ * will be in the ULP list for the lifetime of the system. Doing
+ * duplicate registers is not a problem.
+ */
+ return tcp_register_ulp(&bpf_tcp_ulp_ops);
+}
+
+static int smap_verdict_func(struct smap_psock *psock, struct sk_buff *skb)
+{
+ struct bpf_prog *prog = READ_ONCE(psock->bpf_verdict);
+ int rc;
+
+ if (unlikely(!prog))
+ return __SK_DROP;
+
+ skb_orphan(skb);
+ /* We need to ensure that BPF metadata for maps is also cleared
+ * when we orphan the skb so that we don't have the possibility
+ * to reference a stale map.
+ */
+ TCP_SKB_CB(skb)->bpf.sk_redir = NULL;
+ skb->sk = psock->sock;
+ bpf_compute_data_end_sk_skb(skb);
+ preempt_disable();
+ rc = (*prog->bpf_func)(skb, prog->insnsi);
+ preempt_enable();
+ skb->sk = NULL;
+
+ /* Moving return codes from UAPI namespace into internal namespace */
+ return rc == SK_PASS ?
+ (TCP_SKB_CB(skb)->bpf.sk_redir ? __SK_REDIRECT : __SK_PASS) :
+ __SK_DROP;
+}
+
+static int smap_do_ingress(struct smap_psock *psock, struct sk_buff *skb)
+{
+ struct sock *sk = psock->sock;
+ int copied = 0, num_sg;
+ struct sk_msg_buff *r;
+
+ r = kzalloc(sizeof(struct sk_msg_buff), __GFP_NOWARN | GFP_ATOMIC);
+ if (unlikely(!r))
+ return -EAGAIN;
+
+ if (!sk_rmem_schedule(sk, skb, skb->len)) {
+ kfree(r);
+ return -EAGAIN;
+ }
+
+ sg_init_table(r->sg_data, MAX_SKB_FRAGS);
+ num_sg = skb_to_sgvec(skb, r->sg_data, 0, skb->len);
+ if (unlikely(num_sg < 0)) {
+ kfree(r);
+ return num_sg;
+ }
+ sk_mem_charge(sk, skb->len);
+ copied = skb->len;
+ r->sg_start = 0;
+ r->sg_end = num_sg == MAX_SKB_FRAGS ? 0 : num_sg;
+ r->skb = skb;
+ list_add_tail(&r->list, &psock->ingress);
+ sk->sk_data_ready(sk);
+ return copied;
+}
+
+static void smap_do_verdict(struct smap_psock *psock, struct sk_buff *skb)
+{
+ struct smap_psock *peer;
+ struct sock *sk;
+ __u32 in;
+ int rc;
+
+ rc = smap_verdict_func(psock, skb);
+ switch (rc) {
+ case __SK_REDIRECT:
+ sk = do_sk_redirect_map(skb);
+ if (!sk) {
+ kfree_skb(skb);
+ break;
+ }
+
+ peer = smap_psock_sk(sk);
+ in = (TCP_SKB_CB(skb)->bpf.flags) & BPF_F_INGRESS;
+
+ if (unlikely(!peer || sock_flag(sk, SOCK_DEAD) ||
+ !test_bit(SMAP_TX_RUNNING, &peer->state))) {
+ kfree_skb(skb);
+ break;
+ }
+
+ if (!in && sock_writeable(sk)) {
+ skb_set_owner_w(skb, sk);
+ skb_queue_tail(&peer->rxqueue, skb);
+ schedule_work(&peer->tx_work);
+ break;
+ } else if (in &&
+ atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf) {
+ skb_queue_tail(&peer->rxqueue, skb);
+ schedule_work(&peer->tx_work);
+ break;
+ }
+ /* Fall through and free skb otherwise */
+ case __SK_DROP:
+ default:
+ kfree_skb(skb);
+ }
+}
+
+static void smap_report_sk_error(struct smap_psock *psock, int err)
+{
+ struct sock *sk = psock->sock;
+
+ sk->sk_err = err;
+ sk->sk_error_report(sk);
+}
+
+static void smap_read_sock_strparser(struct strparser *strp,
+ struct sk_buff *skb)
+{
+ struct smap_psock *psock;
+
+ rcu_read_lock();
+ psock = container_of(strp, struct smap_psock, strp);
+ smap_do_verdict(psock, skb);
+ rcu_read_unlock();
+}
+
+/* Called with lock held on socket */
+static void smap_data_ready(struct sock *sk)
+{
+ struct smap_psock *psock;
+
+ rcu_read_lock();
+ psock = smap_psock_sk(sk);
+ if (likely(psock)) {
+ write_lock_bh(&sk->sk_callback_lock);
+ strp_data_ready(&psock->strp);
+ write_unlock_bh(&sk->sk_callback_lock);
+ }
+ rcu_read_unlock();
+}
+
+static void smap_tx_work(struct work_struct *w)
+{
+ struct smap_psock *psock;
+ struct sk_buff *skb;
+ int rem, off, n;
+
+ psock = container_of(w, struct smap_psock, tx_work);
+
+ /* lock sock to avoid losing sk_socket at some point during loop */
+ lock_sock(psock->sock);
+ if (psock->save_skb) {
+ skb = psock->save_skb;
+ rem = psock->save_rem;
+ off = psock->save_off;
+ psock->save_skb = NULL;
+ goto start;
+ }
+
+ while ((skb = skb_dequeue(&psock->rxqueue))) {
+ __u32 flags;
+
+ rem = skb->len;
+ off = 0;
+start:
+ flags = (TCP_SKB_CB(skb)->bpf.flags) & BPF_F_INGRESS;
+ do {
+ if (likely(psock->sock->sk_socket)) {
+ if (flags)
+ n = smap_do_ingress(psock, skb);
+ else
+ n = skb_send_sock_locked(psock->sock,
+ skb, off, rem);
+ } else {
+ n = -EINVAL;
+ }
+
+ if (n <= 0) {
+ if (n == -EAGAIN) {
+ /* Retry when space is available */
+ psock->save_skb = skb;
+ psock->save_rem = rem;
+ psock->save_off = off;
+ goto out;
+ }
+ /* Hard errors break pipe and stop xmit */
+ smap_report_sk_error(psock, n ? -n : EPIPE);
+ clear_bit(SMAP_TX_RUNNING, &psock->state);
+ kfree_skb(skb);
+ goto out;
+ }
+ rem -= n;
+ off += n;
+ } while (rem);
+
+ if (!flags)
+ kfree_skb(skb);
+ }
+out:
+ release_sock(psock->sock);
+}
+
+static void smap_write_space(struct sock *sk)
+{
+ struct smap_psock *psock;
+ void (*write_space)(struct sock *sk);
+
+ rcu_read_lock();
+ psock = smap_psock_sk(sk);
+ if (likely(psock && test_bit(SMAP_TX_RUNNING, &psock->state)))
+ schedule_work(&psock->tx_work);
+ write_space = psock->save_write_space;
+ rcu_read_unlock();
+ write_space(sk);
+}
+
+static void smap_stop_sock(struct smap_psock *psock, struct sock *sk)
+{
+ if (!psock->strp_enabled)
+ return;
+ sk->sk_data_ready = psock->save_data_ready;
+ sk->sk_write_space = psock->save_write_space;
+ psock->save_data_ready = NULL;
+ psock->save_write_space = NULL;
+ strp_stop(&psock->strp);
+ psock->strp_enabled = false;
+}
+
+static void smap_destroy_psock(struct rcu_head *rcu)
+{
+ struct smap_psock *psock = container_of(rcu,
+ struct smap_psock, rcu);
+
+ /* Now that a grace period has passed there is no longer
+ * any reference to this sock in the sockmap so we can
+ * destroy the psock, strparser, and bpf programs. But,
+ * because we use workqueue sync operations we can not
+ * do it in rcu context
+ */
+ schedule_work(&psock->gc_work);
+}
+
+static bool psock_is_smap_sk(struct sock *sk)
+{
+ return inet_csk(sk)->icsk_ulp_ops == &bpf_tcp_ulp_ops;
+}
+
+static void smap_release_sock(struct smap_psock *psock, struct sock *sock)
+{
+ if (refcount_dec_and_test(&psock->refcnt)) {
+ if (psock_is_smap_sk(sock))
+ tcp_cleanup_ulp(sock);
+ write_lock_bh(&sock->sk_callback_lock);
+ smap_stop_sock(psock, sock);
+ write_unlock_bh(&sock->sk_callback_lock);
+ clear_bit(SMAP_TX_RUNNING, &psock->state);
+ rcu_assign_sk_user_data(sock, NULL);
+ call_rcu_sched(&psock->rcu, smap_destroy_psock);
+ }
+}
+
+static int smap_parse_func_strparser(struct strparser *strp,
+ struct sk_buff *skb)
+{
+ struct smap_psock *psock;
+ struct bpf_prog *prog;
+ int rc;
+
+ rcu_read_lock();
+ psock = container_of(strp, struct smap_psock, strp);
+ prog = READ_ONCE(psock->bpf_parse);
+
+ if (unlikely(!prog)) {
+ rcu_read_unlock();
+ return skb->len;
+ }
+
+ /* Attach socket for bpf program to use if needed we can do this
+ * because strparser clones the skb before handing it to a upper
+ * layer, meaning skb_orphan has been called. We NULL sk on the
+ * way out to ensure we don't trigger a BUG_ON in skb/sk operations
+ * later and because we are not charging the memory of this skb to
+ * any socket yet.
+ */
+ skb->sk = psock->sock;
+ bpf_compute_data_end_sk_skb(skb);
+ rc = (*prog->bpf_func)(skb, prog->insnsi);
+ skb->sk = NULL;
+ rcu_read_unlock();
+ return rc;
+}
+
+static int smap_read_sock_done(struct strparser *strp, int err)
+{
+ return err;
+}
+
+static int smap_init_sock(struct smap_psock *psock,
+ struct sock *sk)
+{
+ static const struct strp_callbacks cb = {
+ .rcv_msg = smap_read_sock_strparser,
+ .parse_msg = smap_parse_func_strparser,
+ .read_sock_done = smap_read_sock_done,
+ };
+
+ return strp_init(&psock->strp, sk, &cb);
+}
+
+static void smap_init_progs(struct smap_psock *psock,
+ struct bpf_prog *verdict,
+ struct bpf_prog *parse)
+{
+ struct bpf_prog *orig_parse, *orig_verdict;
+
+ orig_parse = xchg(&psock->bpf_parse, parse);
+ orig_verdict = xchg(&psock->bpf_verdict, verdict);
+
+ if (orig_verdict)
+ bpf_prog_put(orig_verdict);
+ if (orig_parse)
+ bpf_prog_put(orig_parse);
+}
+
+static void smap_start_sock(struct smap_psock *psock, struct sock *sk)
+{
+ if (sk->sk_data_ready == smap_data_ready)
+ return;
+ psock->save_data_ready = sk->sk_data_ready;
+ psock->save_write_space = sk->sk_write_space;
+ sk->sk_data_ready = smap_data_ready;
+ sk->sk_write_space = smap_write_space;
+ psock->strp_enabled = true;
+}
+
+static void sock_map_remove_complete(struct bpf_stab *stab)
+{
+ bpf_map_area_free(stab->sock_map);
+ kfree(stab);
+}
+
+static void smap_gc_work(struct work_struct *w)
+{
+ struct smap_psock_map_entry *e, *tmp;
+ struct sk_msg_buff *md, *mtmp;
+ struct smap_psock *psock;
+
+ psock = container_of(w, struct smap_psock, gc_work);
+
+ /* no callback lock needed because we already detached sockmap ops */
+ if (psock->strp_enabled)
+ strp_done(&psock->strp);
+
+ cancel_work_sync(&psock->tx_work);
+ __skb_queue_purge(&psock->rxqueue);
+
+ /* At this point all strparser and xmit work must be complete */
+ if (psock->bpf_parse)
+ bpf_prog_put(psock->bpf_parse);
+ if (psock->bpf_verdict)
+ bpf_prog_put(psock->bpf_verdict);
+ if (psock->bpf_tx_msg)
+ bpf_prog_put(psock->bpf_tx_msg);
+
+ if (psock->cork) {
+ free_start_sg(psock->sock, psock->cork, true);
+ kfree(psock->cork);
+ }
+
+ list_for_each_entry_safe(md, mtmp, &psock->ingress, list) {
+ list_del(&md->list);
+ free_start_sg(psock->sock, md, true);
+ kfree(md);
+ }
+
+ list_for_each_entry_safe(e, tmp, &psock->maps, list) {
+ list_del(&e->list);
+ kfree(e);
+ }
+
+ if (psock->sk_redir)
+ sock_put(psock->sk_redir);
+
+ sock_put(psock->sock);
+ kfree(psock);
+}
+
+static struct smap_psock *smap_init_psock(struct sock *sock, int node)
+{
+ struct smap_psock *psock;
+
+ psock = kzalloc_node(sizeof(struct smap_psock),
+ GFP_ATOMIC | __GFP_NOWARN,
+ node);
+ if (!psock)
+ return ERR_PTR(-ENOMEM);
+
+ psock->eval = __SK_NONE;
+ psock->sock = sock;
+ skb_queue_head_init(&psock->rxqueue);
+ INIT_WORK(&psock->tx_work, smap_tx_work);
+ INIT_WORK(&psock->gc_work, smap_gc_work);
+ INIT_LIST_HEAD(&psock->maps);
+ INIT_LIST_HEAD(&psock->ingress);
+ refcount_set(&psock->refcnt, 1);
+ spin_lock_init(&psock->maps_lock);
+
+ rcu_assign_sk_user_data(sock, psock);
+ sock_hold(sock);
+ return psock;
+}
+
+static struct bpf_map *sock_map_alloc(union bpf_attr *attr)
+{
+ struct bpf_stab *stab;
+ u64 cost;
+ int err;
+
+ if (!capable(CAP_NET_ADMIN))
+ return ERR_PTR(-EPERM);
+
+ /* check sanity of attributes */
+ if (attr->max_entries == 0 || attr->key_size != 4 ||
+ attr->value_size != 4 || attr->map_flags & ~SOCK_CREATE_FLAG_MASK)
+ return ERR_PTR(-EINVAL);
+
+ err = bpf_tcp_ulp_register();
+ if (err && err != -EEXIST)
+ return ERR_PTR(err);
+
+ stab = kzalloc(sizeof(*stab), GFP_USER);
+ if (!stab)
+ return ERR_PTR(-ENOMEM);
+
+ bpf_map_init_from_attr(&stab->map, attr);
+ raw_spin_lock_init(&stab->lock);
+
+ /* make sure page count doesn't overflow */
+ cost = (u64) stab->map.max_entries * sizeof(struct sock *);
+ err = -EINVAL;
+ if (cost >= U32_MAX - PAGE_SIZE)
+ goto free_stab;
+
+ stab->map.pages = round_up(cost, PAGE_SIZE) >> PAGE_SHIFT;
+
+ /* if map size is larger than memlock limit, reject it early */
+ err = bpf_map_precharge_memlock(stab->map.pages);
+ if (err)
+ goto free_stab;
+
+ err = -ENOMEM;
+ stab->sock_map = bpf_map_area_alloc(stab->map.max_entries *
+ sizeof(struct sock *),
+ stab->map.numa_node);
+ if (!stab->sock_map)
+ goto free_stab;
+
+ return &stab->map;
+free_stab:
+ kfree(stab);
+ return ERR_PTR(err);
+}
+
+static void smap_list_map_remove(struct smap_psock *psock,
+ struct sock **entry)
+{
+ struct smap_psock_map_entry *e, *tmp;
+
+ spin_lock_bh(&psock->maps_lock);
+ list_for_each_entry_safe(e, tmp, &psock->maps, list) {
+ if (e->entry == entry) {
+ list_del(&e->list);
+ kfree(e);
+ }
+ }
+ spin_unlock_bh(&psock->maps_lock);
+}
+
+static void smap_list_hash_remove(struct smap_psock *psock,
+ struct htab_elem *hash_link)
+{
+ struct smap_psock_map_entry *e, *tmp;
+
+ spin_lock_bh(&psock->maps_lock);
+ list_for_each_entry_safe(e, tmp, &psock->maps, list) {
+ struct htab_elem *c = rcu_dereference(e->hash_link);
+
+ if (c == hash_link) {
+ list_del(&e->list);
+ kfree(e);
+ }
+ }
+ spin_unlock_bh(&psock->maps_lock);
+}
+
+static void sock_map_free(struct bpf_map *map)
+{
+ struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
+ int i;
+
+ synchronize_rcu();
+
+ /* At this point no update, lookup or delete operations can happen.
+ * However, be aware we can still get a socket state event updates,
+ * and data ready callabacks that reference the psock from sk_user_data
+ * Also psock worker threads are still in-flight. So smap_release_sock
+ * will only free the psock after cancel_sync on the worker threads
+ * and a grace period expire to ensure psock is really safe to remove.
+ */
+ rcu_read_lock();
+ raw_spin_lock_bh(&stab->lock);
+ for (i = 0; i < stab->map.max_entries; i++) {
+ struct smap_psock *psock;
+ struct sock *sock;
+
+ sock = stab->sock_map[i];
+ if (!sock)
+ continue;
+ stab->sock_map[i] = NULL;
+ psock = smap_psock_sk(sock);
+ /* This check handles a racing sock event that can get the
+ * sk_callback_lock before this case but after xchg happens
+ * causing the refcnt to hit zero and sock user data (psock)
+ * to be null and queued for garbage collection.
+ */
+ if (likely(psock)) {
+ smap_list_map_remove(psock, &stab->sock_map[i]);
+ smap_release_sock(psock, sock);
+ }
+ }
+ raw_spin_unlock_bh(&stab->lock);
+ rcu_read_unlock();
+
+ sock_map_remove_complete(stab);
+}
+
+static int sock_map_get_next_key(struct bpf_map *map, void *key, void *next_key)
+{
+ struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
+ u32 i = key ? *(u32 *)key : U32_MAX;
+ u32 *next = (u32 *)next_key;
+
+ if (i >= stab->map.max_entries) {
+ *next = 0;
+ return 0;
+ }
+
+ if (i == stab->map.max_entries - 1)
+ return -ENOENT;
+
+ *next = i + 1;
+ return 0;
+}
+
+struct sock *__sock_map_lookup_elem(struct bpf_map *map, u32 key)
+{
+ struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
+
+ if (key >= map->max_entries)
+ return NULL;
+
+ return READ_ONCE(stab->sock_map[key]);
+}
+
+static int sock_map_delete_elem(struct bpf_map *map, void *key)
+{
+ struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
+ struct smap_psock *psock;
+ int k = *(u32 *)key;
+ struct sock *sock;
+
+ if (k >= map->max_entries)
+ return -EINVAL;
+
+ raw_spin_lock_bh(&stab->lock);
+ sock = stab->sock_map[k];
+ stab->sock_map[k] = NULL;
+ raw_spin_unlock_bh(&stab->lock);
+ if (!sock)
+ return -EINVAL;
+
+ psock = smap_psock_sk(sock);
+ if (!psock)
+ return 0;
+ if (psock->bpf_parse) {
+ write_lock_bh(&sock->sk_callback_lock);
+ smap_stop_sock(psock, sock);
+ write_unlock_bh(&sock->sk_callback_lock);
+ }
+ smap_list_map_remove(psock, &stab->sock_map[k]);
+ smap_release_sock(psock, sock);
+ return 0;
+}
+
+/* Locking notes: Concurrent updates, deletes, and lookups are allowed and are
+ * done inside rcu critical sections. This ensures on updates that the psock
+ * will not be released via smap_release_sock() until concurrent updates/deletes
+ * complete. All operations operate on sock_map using cmpxchg and xchg
+ * operations to ensure we do not get stale references. Any reads into the
+ * map must be done with READ_ONCE() because of this.
+ *
+ * A psock is destroyed via call_rcu and after any worker threads are cancelled
+ * and syncd so we are certain all references from the update/lookup/delete
+ * operations as well as references in the data path are no longer in use.
+ *
+ * Psocks may exist in multiple maps, but only a single set of parse/verdict
+ * programs may be inherited from the maps it belongs to. A reference count
+ * is kept with the total number of references to the psock from all maps. The
+ * psock will not be released until this reaches zero. The psock and sock
+ * user data data use the sk_callback_lock to protect critical data structures
+ * from concurrent access. This allows us to avoid two updates from modifying
+ * the user data in sock and the lock is required anyways for modifying
+ * callbacks, we simply increase its scope slightly.
+ *
+ * Rules to follow,
+ * - psock must always be read inside RCU critical section
+ * - sk_user_data must only be modified inside sk_callback_lock and read
+ * inside RCU critical section.
+ * - psock->maps list must only be read & modified inside sk_callback_lock
+ * - sock_map must use READ_ONCE and (cmp)xchg operations
+ * - BPF verdict/parse programs must use READ_ONCE and xchg operations
+ */
+
+static int __sock_map_ctx_update_elem(struct bpf_map *map,
+ struct bpf_sock_progs *progs,
+ struct sock *sock,
+ void *key)
+{
+ struct bpf_prog *verdict, *parse, *tx_msg;
+ struct smap_psock *psock;
+ bool new = false;
+ int err = 0;
+
+ /* 1. If sock map has BPF programs those will be inherited by the
+ * sock being added. If the sock is already attached to BPF programs
+ * this results in an error.
+ */
+ verdict = READ_ONCE(progs->bpf_verdict);
+ parse = READ_ONCE(progs->bpf_parse);
+ tx_msg = READ_ONCE(progs->bpf_tx_msg);
+
+ if (parse && verdict) {
+ /* bpf prog refcnt may be zero if a concurrent attach operation
+ * removes the program after the above READ_ONCE() but before
+ * we increment the refcnt. If this is the case abort with an
+ * error.
+ */
+ verdict = bpf_prog_inc_not_zero(verdict);
+ if (IS_ERR(verdict))
+ return PTR_ERR(verdict);
+
+ parse = bpf_prog_inc_not_zero(parse);
+ if (IS_ERR(parse)) {
+ bpf_prog_put(verdict);
+ return PTR_ERR(parse);
+ }
+ }
+
+ if (tx_msg) {
+ tx_msg = bpf_prog_inc_not_zero(tx_msg);
+ if (IS_ERR(tx_msg)) {
+ if (parse && verdict) {
+ bpf_prog_put(parse);
+ bpf_prog_put(verdict);
+ }
+ return PTR_ERR(tx_msg);
+ }
+ }
+
+ psock = smap_psock_sk(sock);
+
+ /* 2. Do not allow inheriting programs if psock exists and has
+ * already inherited programs. This would create confusion on
+ * which parser/verdict program is running. If no psock exists
+ * create one. Inside sk_callback_lock to ensure concurrent create
+ * doesn't update user data.
+ */
+ if (psock) {
+ if (!psock_is_smap_sk(sock)) {
+ err = -EBUSY;
+ goto out_progs;
+ }
+ if (READ_ONCE(psock->bpf_parse) && parse) {
+ err = -EBUSY;
+ goto out_progs;
+ }
+ if (READ_ONCE(psock->bpf_tx_msg) && tx_msg) {
+ err = -EBUSY;
+ goto out_progs;
+ }
+ if (!refcount_inc_not_zero(&psock->refcnt)) {
+ err = -EAGAIN;
+ goto out_progs;
+ }
+ } else {
+ psock = smap_init_psock(sock, map->numa_node);
+ if (IS_ERR(psock)) {
+ err = PTR_ERR(psock);
+ goto out_progs;
+ }
+
+ set_bit(SMAP_TX_RUNNING, &psock->state);
+ new = true;
+ }
+
+ /* 3. At this point we have a reference to a valid psock that is
+ * running. Attach any BPF programs needed.
+ */
+ if (tx_msg)
+ bpf_tcp_msg_add(psock, sock, tx_msg);
+ if (new) {
+ err = tcp_set_ulp_id(sock, TCP_ULP_BPF);
+ if (err)
+ goto out_free;
+ }
+
+ if (parse && verdict && !psock->strp_enabled) {
+ err = smap_init_sock(psock, sock);
+ if (err)
+ goto out_free;
+ smap_init_progs(psock, verdict, parse);
+ write_lock_bh(&sock->sk_callback_lock);
+ smap_start_sock(psock, sock);
+ write_unlock_bh(&sock->sk_callback_lock);
+ }
+
+ return err;
+out_free:
+ smap_release_sock(psock, sock);
+out_progs:
+ if (parse && verdict) {
+ bpf_prog_put(parse);
+ bpf_prog_put(verdict);
+ }
+ if (tx_msg)
+ bpf_prog_put(tx_msg);
+ return err;
+}
+
+static int sock_map_ctx_update_elem(struct bpf_sock_ops_kern *skops,
+ struct bpf_map *map,
+ void *key, u64 flags)
+{
+ struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
+ struct bpf_sock_progs *progs = &stab->progs;
+ struct sock *osock, *sock = skops->sk;
+ struct smap_psock_map_entry *e;
+ struct smap_psock *psock;
+ u32 i = *(u32 *)key;
+ int err;
+
+ if (unlikely(flags > BPF_EXIST))
+ return -EINVAL;
+ if (unlikely(i >= stab->map.max_entries))
+ return -E2BIG;
+
+ e = kzalloc(sizeof(*e), GFP_ATOMIC | __GFP_NOWARN);
+ if (!e)
+ return -ENOMEM;
+
+ err = __sock_map_ctx_update_elem(map, progs, sock, key);
+ if (err)
+ goto out;
+
+ /* psock guaranteed to be present. */
+ psock = smap_psock_sk(sock);
+ raw_spin_lock_bh(&stab->lock);
+ osock = stab->sock_map[i];
+ if (osock && flags == BPF_NOEXIST) {
+ err = -EEXIST;
+ goto out_unlock;
+ }
+ if (!osock && flags == BPF_EXIST) {
+ err = -ENOENT;
+ goto out_unlock;
+ }
+
+ e->entry = &stab->sock_map[i];
+ e->map = map;
+ spin_lock_bh(&psock->maps_lock);
+ list_add_tail(&e->list, &psock->maps);
+ spin_unlock_bh(&psock->maps_lock);
+
+ stab->sock_map[i] = sock;
+ if (osock) {
+ psock = smap_psock_sk(osock);
+ smap_list_map_remove(psock, &stab->sock_map[i]);
+ smap_release_sock(psock, osock);
+ }
+ raw_spin_unlock_bh(&stab->lock);
+ return 0;
+out_unlock:
+ smap_release_sock(psock, sock);
+ raw_spin_unlock_bh(&stab->lock);
+out:
+ kfree(e);
+ return err;
+}
+
+int sock_map_prog(struct bpf_map *map, struct bpf_prog *prog, u32 type)
+{
+ struct bpf_sock_progs *progs;
+ struct bpf_prog *orig;
+
+ if (map->map_type == BPF_MAP_TYPE_SOCKMAP) {
+ struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
+
+ progs = &stab->progs;
+ } else if (map->map_type == BPF_MAP_TYPE_SOCKHASH) {
+ struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
+
+ progs = &htab->progs;
+ } else {
+ return -EINVAL;
+ }
+
+ switch (type) {
+ case BPF_SK_MSG_VERDICT:
+ orig = xchg(&progs->bpf_tx_msg, prog);
+ break;
+ case BPF_SK_SKB_STREAM_PARSER:
+ orig = xchg(&progs->bpf_parse, prog);
+ break;
+ case BPF_SK_SKB_STREAM_VERDICT:
+ orig = xchg(&progs->bpf_verdict, prog);
+ break;
+ default:
+ return -EOPNOTSUPP;
+ }
+
+ if (orig)
+ bpf_prog_put(orig);
+
+ return 0;
+}
+
+int sockmap_get_from_fd(const union bpf_attr *attr, int type,
+ struct bpf_prog *prog)
+{
+ int ufd = attr->target_fd;
+ struct bpf_map *map;
+ struct fd f;
+ int err;
+
+ f = fdget(ufd);
+ map = __bpf_map_get(f);
+ if (IS_ERR(map))
+ return PTR_ERR(map);
+
+ err = sock_map_prog(map, prog, attr->attach_type);
+ fdput(f);
+ return err;
+}
+
+static void *sock_map_lookup(struct bpf_map *map, void *key)
+{
+ return NULL;
+}
+
+static int sock_map_update_elem(struct bpf_map *map,
+ void *key, void *value, u64 flags)
+{
+ struct bpf_sock_ops_kern skops;
+ u32 fd = *(u32 *)value;
+ struct socket *socket;
+ int err;
+
+ socket = sockfd_lookup(fd, &err);
+ if (!socket)
+ return err;
+
+ skops.sk = socket->sk;
+ if (!skops.sk) {
+ fput(socket->file);
+ return -EINVAL;
+ }
+
+ /* ULPs are currently supported only for TCP sockets in ESTABLISHED
+ * state.
+ */
+ if (skops.sk->sk_type != SOCK_STREAM ||
+ skops.sk->sk_protocol != IPPROTO_TCP ||
+ skops.sk->sk_state != TCP_ESTABLISHED) {
+ fput(socket->file);
+ return -EOPNOTSUPP;
+ }
+
+ lock_sock(skops.sk);
+ preempt_disable();
+ rcu_read_lock();
+ err = sock_map_ctx_update_elem(&skops, map, key, flags);
+ rcu_read_unlock();
+ preempt_enable();
+ release_sock(skops.sk);
+ fput(socket->file);
+ return err;
+}
+
+static void sock_map_release(struct bpf_map *map)
+{
+ struct bpf_sock_progs *progs;
+ struct bpf_prog *orig;
+
+ if (map->map_type == BPF_MAP_TYPE_SOCKMAP) {
+ struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
+
+ progs = &stab->progs;
+ } else {
+ struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
+
+ progs = &htab->progs;
+ }
+
+ orig = xchg(&progs->bpf_parse, NULL);
+ if (orig)
+ bpf_prog_put(orig);
+ orig = xchg(&progs->bpf_verdict, NULL);
+ if (orig)
+ bpf_prog_put(orig);
+
+ orig = xchg(&progs->bpf_tx_msg, NULL);
+ if (orig)
+ bpf_prog_put(orig);
+}
+
+static struct bpf_map *sock_hash_alloc(union bpf_attr *attr)
+{
+ struct bpf_htab *htab;
+ int i, err;
+ u64 cost;
+
+ if (!capable(CAP_NET_ADMIN))
+ return ERR_PTR(-EPERM);
+
+ /* check sanity of attributes */
+ if (attr->max_entries == 0 ||
+ attr->key_size == 0 ||
+ attr->value_size != 4 ||
+ attr->map_flags & ~SOCK_CREATE_FLAG_MASK)
+ return ERR_PTR(-EINVAL);
+
+ if (attr->key_size > MAX_BPF_STACK)
+ /* eBPF programs initialize keys on stack, so they cannot be
+ * larger than max stack size
+ */
+ return ERR_PTR(-E2BIG);
+
+ err = bpf_tcp_ulp_register();
+ if (err && err != -EEXIST)
+ return ERR_PTR(err);
+
+ htab = kzalloc(sizeof(*htab), GFP_USER);
+ if (!htab)
+ return ERR_PTR(-ENOMEM);
+
+ bpf_map_init_from_attr(&htab->map, attr);
+
+ htab->n_buckets = roundup_pow_of_two(htab->map.max_entries);
+ htab->elem_size = sizeof(struct htab_elem) +
+ round_up(htab->map.key_size, 8);
+ err = -EINVAL;
+ if (htab->n_buckets == 0 ||
+ htab->n_buckets > U32_MAX / sizeof(struct bucket))
+ goto free_htab;
+
+ cost = (u64) htab->n_buckets * sizeof(struct bucket) +
+ (u64) htab->elem_size * htab->map.max_entries;
+
+ if (cost >= U32_MAX - PAGE_SIZE)
+ goto free_htab;
+
+ htab->map.pages = round_up(cost, PAGE_SIZE) >> PAGE_SHIFT;
+ err = bpf_map_precharge_memlock(htab->map.pages);
+ if (err)
+ goto free_htab;
+
+ err = -ENOMEM;
+ htab->buckets = bpf_map_area_alloc(
+ htab->n_buckets * sizeof(struct bucket),
+ htab->map.numa_node);
+ if (!htab->buckets)
+ goto free_htab;
+
+ for (i = 0; i < htab->n_buckets; i++) {
+ INIT_HLIST_HEAD(&htab->buckets[i].head);
+ raw_spin_lock_init(&htab->buckets[i].lock);
+ }
+
+ return &htab->map;
+free_htab:
+ kfree(htab);
+ return ERR_PTR(err);
+}
+
+static void __bpf_htab_free(struct rcu_head *rcu)
+{
+ struct bpf_htab *htab;
+
+ htab = container_of(rcu, struct bpf_htab, rcu);
+ bpf_map_area_free(htab->buckets);
+ kfree(htab);
+}
+
+static void sock_hash_free(struct bpf_map *map)
+{
+ struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
+ int i;
+
+ synchronize_rcu();
+
+ /* At this point no update, lookup or delete operations can happen.
+ * However, be aware we can still get a socket state event updates,
+ * and data ready callabacks that reference the psock from sk_user_data
+ * Also psock worker threads are still in-flight. So smap_release_sock
+ * will only free the psock after cancel_sync on the worker threads
+ * and a grace period expire to ensure psock is really safe to remove.
+ */
+ rcu_read_lock();
+ for (i = 0; i < htab->n_buckets; i++) {
+ struct bucket *b = __select_bucket(htab, i);
+ struct hlist_head *head;
+ struct hlist_node *n;
+ struct htab_elem *l;
+
+ raw_spin_lock_bh(&b->lock);
+ head = &b->head;
+ hlist_for_each_entry_safe(l, n, head, hash_node) {
+ struct sock *sock = l->sk;
+ struct smap_psock *psock;
+
+ hlist_del_rcu(&l->hash_node);
+ psock = smap_psock_sk(sock);
+ /* This check handles a racing sock event that can get
+ * the sk_callback_lock before this case but after xchg
+ * causing the refcnt to hit zero and sock user data
+ * (psock) to be null and queued for garbage collection.
+ */
+ if (likely(psock)) {
+ smap_list_hash_remove(psock, l);
+ smap_release_sock(psock, sock);
+ }
+ free_htab_elem(htab, l);
+ }
+ raw_spin_unlock_bh(&b->lock);
+ }
+ rcu_read_unlock();
+ call_rcu(&htab->rcu, __bpf_htab_free);
+}
+
+static struct htab_elem *alloc_sock_hash_elem(struct bpf_htab *htab,
+ void *key, u32 key_size, u32 hash,
+ struct sock *sk,
+ struct htab_elem *old_elem)
+{
+ struct htab_elem *l_new;
+
+ if (atomic_inc_return(&htab->count) > htab->map.max_entries) {
+ if (!old_elem) {
+ atomic_dec(&htab->count);
+ return ERR_PTR(-E2BIG);
+ }
+ }
+ l_new = kmalloc_node(htab->elem_size, GFP_ATOMIC | __GFP_NOWARN,
+ htab->map.numa_node);
+ if (!l_new) {
+ atomic_dec(&htab->count);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ memcpy(l_new->key, key, key_size);
+ l_new->sk = sk;
+ l_new->hash = hash;
+ return l_new;
+}
+
+static inline u32 htab_map_hash(const void *key, u32 key_len)
+{
+ return jhash(key, key_len, 0);
+}
+
+static int sock_hash_get_next_key(struct bpf_map *map,
+ void *key, void *next_key)
+{
+ struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
+ struct htab_elem *l, *next_l;
+ struct hlist_head *h;
+ u32 hash, key_size;
+ int i = 0;
+
+ WARN_ON_ONCE(!rcu_read_lock_held());
+
+ key_size = map->key_size;
+ if (!key)
+ goto find_first_elem;
+ hash = htab_map_hash(key, key_size);
+ h = select_bucket(htab, hash);
+
+ l = lookup_elem_raw(h, hash, key, key_size);
+ if (!l)
+ goto find_first_elem;
+ next_l = hlist_entry_safe(
+ rcu_dereference_raw(hlist_next_rcu(&l->hash_node)),
+ struct htab_elem, hash_node);
+ if (next_l) {
+ memcpy(next_key, next_l->key, key_size);
+ return 0;
+ }
+
+ /* no more elements in this hash list, go to the next bucket */
+ i = hash & (htab->n_buckets - 1);
+ i++;
+
+find_first_elem:
+ /* iterate over buckets */
+ for (; i < htab->n_buckets; i++) {
+ h = select_bucket(htab, i);
+
+ /* pick first element in the bucket */
+ next_l = hlist_entry_safe(
+ rcu_dereference_raw(hlist_first_rcu(h)),
+ struct htab_elem, hash_node);
+ if (next_l) {
+ /* if it's not empty, just return it */
+ memcpy(next_key, next_l->key, key_size);
+ return 0;
+ }
+ }
+
+ /* iterated over all buckets and all elements */
+ return -ENOENT;
+}
+
+static int sock_hash_ctx_update_elem(struct bpf_sock_ops_kern *skops,
+ struct bpf_map *map,
+ void *key, u64 map_flags)
+{
+ struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
+ struct bpf_sock_progs *progs = &htab->progs;
+ struct htab_elem *l_new = NULL, *l_old;
+ struct smap_psock_map_entry *e = NULL;
+ struct hlist_head *head;
+ struct smap_psock *psock;
+ u32 key_size, hash;
+ struct sock *sock;
+ struct bucket *b;
+ int err;
+
+ sock = skops->sk;
+
+ if (sock->sk_type != SOCK_STREAM ||
+ sock->sk_protocol != IPPROTO_TCP)
+ return -EOPNOTSUPP;
+
+ if (unlikely(map_flags > BPF_EXIST))
+ return -EINVAL;
+
+ e = kzalloc(sizeof(*e), GFP_ATOMIC | __GFP_NOWARN);
+ if (!e)
+ return -ENOMEM;
+
+ WARN_ON_ONCE(!rcu_read_lock_held());
+ key_size = map->key_size;
+ hash = htab_map_hash(key, key_size);
+ b = __select_bucket(htab, hash);
+ head = &b->head;
+
+ err = __sock_map_ctx_update_elem(map, progs, sock, key);
+ if (err)
+ goto err;
+
+ /* psock is valid here because otherwise above *ctx_update_elem would
+ * have thrown an error. It is safe to skip error check.
+ */
+ psock = smap_psock_sk(sock);
+ raw_spin_lock_bh(&b->lock);
+ l_old = lookup_elem_raw(head, hash, key, key_size);
+ if (l_old && map_flags == BPF_NOEXIST) {
+ err = -EEXIST;
+ goto bucket_err;
+ }
+ if (!l_old && map_flags == BPF_EXIST) {
+ err = -ENOENT;
+ goto bucket_err;
+ }
+
+ l_new = alloc_sock_hash_elem(htab, key, key_size, hash, sock, l_old);
+ if (IS_ERR(l_new)) {
+ err = PTR_ERR(l_new);
+ goto bucket_err;
+ }
+
+ rcu_assign_pointer(e->hash_link, l_new);
+ e->map = map;
+ spin_lock_bh(&psock->maps_lock);
+ list_add_tail(&e->list, &psock->maps);
+ spin_unlock_bh(&psock->maps_lock);
+
+ /* add new element to the head of the list, so that
+ * concurrent search will find it before old elem
+ */
+ hlist_add_head_rcu(&l_new->hash_node, head);
+ if (l_old) {
+ psock = smap_psock_sk(l_old->sk);
+
+ hlist_del_rcu(&l_old->hash_node);
+ smap_list_hash_remove(psock, l_old);
+ smap_release_sock(psock, l_old->sk);
+ free_htab_elem(htab, l_old);
+ }
+ raw_spin_unlock_bh(&b->lock);
+ return 0;
+bucket_err:
+ smap_release_sock(psock, sock);
+ raw_spin_unlock_bh(&b->lock);
+err:
+ kfree(e);
+ return err;
+}
+
+static int sock_hash_update_elem(struct bpf_map *map,
+ void *key, void *value, u64 flags)
+{
+ struct bpf_sock_ops_kern skops;
+ u32 fd = *(u32 *)value;
+ struct socket *socket;
+ int err;
+
+ socket = sockfd_lookup(fd, &err);
+ if (!socket)
+ return err;
+
+ skops.sk = socket->sk;
+ if (!skops.sk) {
+ fput(socket->file);
+ return -EINVAL;
+ }
+
+ /* ULPs are currently supported only for TCP sockets in ESTABLISHED
+ * state.
+ */
+ if (skops.sk->sk_type != SOCK_STREAM ||
+ skops.sk->sk_protocol != IPPROTO_TCP ||
+ skops.sk->sk_state != TCP_ESTABLISHED) {
+ fput(socket->file);
+ return -EOPNOTSUPP;
+ }
+
+ lock_sock(skops.sk);
+ preempt_disable();
+ rcu_read_lock();
+ err = sock_hash_ctx_update_elem(&skops, map, key, flags);
+ rcu_read_unlock();
+ preempt_enable();
+ release_sock(skops.sk);
+ fput(socket->file);
+ return err;
+}
+
+static int sock_hash_delete_elem(struct bpf_map *map, void *key)
+{
+ struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
+ struct hlist_head *head;
+ struct bucket *b;
+ struct htab_elem *l;
+ u32 hash, key_size;
+ int ret = -ENOENT;
+
+ key_size = map->key_size;
+ hash = htab_map_hash(key, key_size);
+ b = __select_bucket(htab, hash);
+ head = &b->head;
+
+ raw_spin_lock_bh(&b->lock);
+ l = lookup_elem_raw(head, hash, key, key_size);
+ if (l) {
+ struct sock *sock = l->sk;
+ struct smap_psock *psock;
+
+ hlist_del_rcu(&l->hash_node);
+ psock = smap_psock_sk(sock);
+ /* This check handles a racing sock event that can get the
+ * sk_callback_lock before this case but after xchg happens
+ * causing the refcnt to hit zero and sock user data (psock)
+ * to be null and queued for garbage collection.
+ */
+ if (likely(psock)) {
+ smap_list_hash_remove(psock, l);
+ smap_release_sock(psock, sock);
+ }
+ free_htab_elem(htab, l);
+ ret = 0;
+ }
+ raw_spin_unlock_bh(&b->lock);
+ return ret;
+}
+
+struct sock *__sock_hash_lookup_elem(struct bpf_map *map, void *key)
+{
+ struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
+ struct hlist_head *head;
+ struct htab_elem *l;
+ u32 key_size, hash;
+ struct bucket *b;
+ struct sock *sk;
+
+ key_size = map->key_size;
+ hash = htab_map_hash(key, key_size);
+ b = __select_bucket(htab, hash);
+ head = &b->head;
+
+ l = lookup_elem_raw(head, hash, key, key_size);
+ sk = l ? l->sk : NULL;
+ return sk;
+}
+
+const struct bpf_map_ops sock_map_ops = {
+ .map_alloc = sock_map_alloc,
+ .map_free = sock_map_free,
+ .map_lookup_elem = sock_map_lookup,
+ .map_get_next_key = sock_map_get_next_key,
+ .map_update_elem = sock_map_update_elem,
+ .map_delete_elem = sock_map_delete_elem,
+ .map_release_uref = sock_map_release,
+ .map_check_btf = map_check_no_btf,
+};
+
+const struct bpf_map_ops sock_hash_ops = {
+ .map_alloc = sock_hash_alloc,
+ .map_free = sock_hash_free,
+ .map_lookup_elem = sock_map_lookup,
+ .map_get_next_key = sock_hash_get_next_key,
+ .map_update_elem = sock_hash_update_elem,
+ .map_delete_elem = sock_hash_delete_elem,
+ .map_release_uref = sock_map_release,
+ .map_check_btf = map_check_no_btf,
+};
+
+static bool bpf_is_valid_sock_op(struct bpf_sock_ops_kern *ops)
+{
+ return ops->op == BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB ||
+ ops->op == BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB;
+}
+BPF_CALL_4(bpf_sock_map_update, struct bpf_sock_ops_kern *, bpf_sock,
+ struct bpf_map *, map, void *, key, u64, flags)
+{
+ WARN_ON_ONCE(!rcu_read_lock_held());
+
+ /* ULPs are currently supported only for TCP sockets in ESTABLISHED
+ * state. This checks that the sock ops triggering the update is
+ * one indicating we are (or will be soon) in an ESTABLISHED state.
+ */
+ if (!bpf_is_valid_sock_op(bpf_sock))
+ return -EOPNOTSUPP;
+ return sock_map_ctx_update_elem(bpf_sock, map, key, flags);
+}
+
+const struct bpf_func_proto bpf_sock_map_update_proto = {
+ .func = bpf_sock_map_update,
+ .gpl_only = false,
+ .pkt_access = true,
+ .ret_type = RET_INTEGER,
+ .arg1_type = ARG_PTR_TO_CTX,
+ .arg2_type = ARG_CONST_MAP_PTR,
+ .arg3_type = ARG_PTR_TO_MAP_KEY,
+ .arg4_type = ARG_ANYTHING,
+};
+
+BPF_CALL_4(bpf_sock_hash_update, struct bpf_sock_ops_kern *, bpf_sock,
+ struct bpf_map *, map, void *, key, u64, flags)
+{
+ WARN_ON_ONCE(!rcu_read_lock_held());
+
+ if (!bpf_is_valid_sock_op(bpf_sock))
+ return -EOPNOTSUPP;
+ return sock_hash_ctx_update_elem(bpf_sock, map, key, flags);
+}
+
+const struct bpf_func_proto bpf_sock_hash_update_proto = {
+ .func = bpf_sock_hash_update,
+ .gpl_only = false,
+ .pkt_access = true,
+ .ret_type = RET_INTEGER,
+ .arg1_type = ARG_PTR_TO_CTX,
+ .arg2_type = ARG_CONST_MAP_PTR,
+ .arg3_type = ARG_PTR_TO_MAP_KEY,
+ .arg4_type = ARG_ANYTHING,
+};