aboutsummaryrefslogtreecommitdiff
path: root/kernel/bpf/sockmap.c
diff options
context:
space:
mode:
Diffstat (limited to 'kernel/bpf/sockmap.c')
-rw-r--r--kernel/bpf/sockmap.c2631
1 files changed, 0 insertions, 2631 deletions
diff --git a/kernel/bpf/sockmap.c b/kernel/bpf/sockmap.c
deleted file mode 100644
index 0a0f2ec75370..000000000000
--- a/kernel/bpf/sockmap.c
+++ /dev/null
@@ -1,2631 +0,0 @@
-/* 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,
-};
Powered by cgit, Gruvboxed by Blaster4385.