diff options
| -rw-r--r-- | include/linux/bpf.h | 1 | ||||
| -rw-r--r-- | include/linux/bpf_types.h | 1 | ||||
| -rw-r--r-- | include/linux/filter.h | 17 | ||||
| -rw-r--r-- | include/uapi/linux/bpf.h | 22 | ||||
| -rw-r--r-- | kernel/bpf/sockmap.c | 712 | ||||
| -rw-r--r-- | kernel/bpf/syscall.c | 14 | ||||
| -rw-r--r-- | kernel/bpf/verifier.c | 5 | ||||
| -rw-r--r-- | net/core/filter.c | 106 |
8 files changed, 857 insertions, 21 deletions
diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 66df387106de..819229c80eca 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -21,6 +21,7 @@ struct bpf_verifier_env; struct perf_event; struct bpf_prog; struct bpf_map; +struct sock; /* map is generic key/value storage optionally accesible by eBPF programs */ struct bpf_map_ops { diff --git a/include/linux/bpf_types.h b/include/linux/bpf_types.h index 19b8349a3809..5e2e8a49fb21 100644 --- a/include/linux/bpf_types.h +++ b/include/linux/bpf_types.h @@ -13,6 +13,7 @@ BPF_PROG_TYPE(BPF_PROG_TYPE_LWT_OUT, lwt_inout) BPF_PROG_TYPE(BPF_PROG_TYPE_LWT_XMIT, lwt_xmit) BPF_PROG_TYPE(BPF_PROG_TYPE_SOCK_OPS, sock_ops) BPF_PROG_TYPE(BPF_PROG_TYPE_SK_SKB, sk_skb) +BPF_PROG_TYPE(BPF_PROG_TYPE_SK_MSG, sk_msg) #endif #ifdef CONFIG_BPF_EVENTS BPF_PROG_TYPE(BPF_PROG_TYPE_KPROBE, kprobe) diff --git a/include/linux/filter.h b/include/linux/filter.h index fdb691b520c0..109d05ccea9a 100644 --- a/include/linux/filter.h +++ b/include/linux/filter.h @@ -507,6 +507,22 @@ struct xdp_buff { struct xdp_rxq_info *rxq; }; +struct sk_msg_buff { + void *data; + void *data_end; + __u32 apply_bytes; + __u32 cork_bytes; + int sg_copybreak; + int sg_start; + int sg_curr; + int sg_end; + struct scatterlist sg_data[MAX_SKB_FRAGS]; + bool sg_copy[MAX_SKB_FRAGS]; + __u32 key; + __u32 flags; + struct bpf_map *map; +}; + /* Compute the linear packet data range [data, data_end) which * will be accessed by various program types (cls_bpf, act_bpf, * lwt, ...). Subsystems allowing direct data access must (!) @@ -771,6 +787,7 @@ xdp_data_meta_unsupported(const struct xdp_buff *xdp) void bpf_warn_invalid_xdp_action(u32 act); struct sock *do_sk_redirect_map(struct sk_buff *skb); +struct sock *do_msg_redirect_map(struct sk_msg_buff *md); #ifdef CONFIG_BPF_JIT extern int bpf_jit_enable; diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 1e15d1724d89..ef529539abde 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -133,6 +133,7 @@ enum bpf_prog_type { BPF_PROG_TYPE_SOCK_OPS, BPF_PROG_TYPE_SK_SKB, BPF_PROG_TYPE_CGROUP_DEVICE, + BPF_PROG_TYPE_SK_MSG, }; enum bpf_attach_type { @@ -143,6 +144,7 @@ enum bpf_attach_type { BPF_SK_SKB_STREAM_PARSER, BPF_SK_SKB_STREAM_VERDICT, BPF_CGROUP_DEVICE, + BPF_SK_MSG_VERDICT, __MAX_BPF_ATTACH_TYPE }; @@ -718,6 +720,15 @@ union bpf_attr { * int bpf_override_return(pt_regs, rc) * @pt_regs: pointer to struct pt_regs * @rc: the return value to set + * + * int bpf_msg_redirect_map(map, key, flags) + * Redirect msg to a sock in map using key as a lookup key for the + * sock in map. + * @map: pointer to sockmap + * @key: key to lookup sock in map + * @flags: reserved for future use + * Return: SK_PASS + * */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \ @@ -779,7 +790,8 @@ union bpf_attr { FN(perf_prog_read_value), \ FN(getsockopt), \ FN(override_return), \ - FN(sock_ops_cb_flags_set), + FN(sock_ops_cb_flags_set), \ + FN(msg_redirect_map), /* integer value in 'imm' field of BPF_CALL instruction selects which helper * function eBPF program intends to call @@ -942,6 +954,14 @@ enum sk_action { SK_PASS, }; +/* user accessible metadata for SK_MSG packet hook, new fields must + * be added to the end of this structure + */ +struct sk_msg_md { + void *data; + void *data_end; +}; + #define BPF_TAG_SIZE 8 struct bpf_prog_info { diff --git a/kernel/bpf/sockmap.c b/kernel/bpf/sockmap.c index 051b224270e3..69c5bccabd22 100644 --- a/kernel/bpf/sockmap.c +++ b/kernel/bpf/sockmap.c @@ -38,6 +38,7 @@ #include <linux/skbuff.h> #include <linux/workqueue.h> #include <linux/list.h> +#include <linux/mm.h> #include <net/strparser.h> #include <net/tcp.h> @@ -47,6 +48,7 @@ struct bpf_stab { struct bpf_map map; struct sock **sock_map; + struct bpf_prog *bpf_tx_msg; struct bpf_prog *bpf_parse; struct bpf_prog *bpf_verdict; }; @@ -73,7 +75,16 @@ struct smap_psock { 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 strparser strp; + struct bpf_prog *bpf_tx_msg; struct bpf_prog *bpf_parse; struct bpf_prog *bpf_verdict; struct list_head maps; @@ -91,6 +102,11 @@ struct smap_psock { void (*save_write_space)(struct sock *sk); }; +static void smap_release_sock(struct smap_psock *psock, struct sock *sock); +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 inline struct smap_psock *smap_psock_sk(const struct sock *sk) { return rcu_dereference_sk_user_data(sk); @@ -115,27 +131,41 @@ static int bpf_tcp_init(struct sock *sk) psock->save_close = sk->sk_prot->close; psock->sk_proto = sk->sk_prot; + + if (psock->bpf_tx_msg) { + tcp_bpf_proto.sendmsg = bpf_tcp_sendmsg; + tcp_bpf_proto.sendpage = bpf_tcp_sendpage; + } + sk->sk_prot = &tcp_bpf_proto; 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); + 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 (likely(psock)) { - sk->sk_prot = psock->sk_proto; - psock->sk_proto = NULL; + if (psock->cork) { + free_start_sg(psock->sock, psock->cork); + kfree(psock->cork); + psock->cork = NULL; } + + sk->sk_prot = psock->sk_proto; + psock->sk_proto = NULL; +out: rcu_read_unlock(); } -static void smap_release_sock(struct smap_psock *psock, struct sock *sock); - static void bpf_tcp_close(struct sock *sk, long timeout) { void (*close_fun)(struct sock *sk, long timeout); @@ -174,6 +204,7 @@ enum __sk_action { __SK_DROP = 0, __SK_PASS, __SK_REDIRECT, + __SK_NONE, }; static struct tcp_ulp_ops bpf_tcp_ulp_ops __read_mostly = { @@ -185,10 +216,621 @@ static struct tcp_ulp_ops bpf_tcp_ulp_ops __read_mostly = { .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; + size -= ret; + offset += ret; + if (uncharge) + sk_mem_uncharge(sk, ret); + goto retry; + } + + sg->length = size; + sg->offset = offset; + 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; + memset(sg, 0, sizeof(*sg)); + + 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) +{ + 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; + sk_mem_uncharge(sk, bytes); + break; + } + + 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; + } +} + +static int free_sg(struct sock *sk, int start, struct sk_msg_buff *md) +{ + struct scatterlist *sg = md->sg_data; + int i = start, free = 0; + + while (sg[i].length) { + free += sg[i].length; + sk_mem_uncharge(sk, sg[i].length); + 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; + } + + return free; +} + +static int free_start_sg(struct sock *sk, struct sk_msg_buff *md) +{ + int free = free_sg(sk, md->sg_start, md); + + 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); +} + +static int bpf_map_msg_verdict(int _rc, struct sk_msg_buff *md) +{ + return ((_rc == SK_PASS) ? + (md->map ? __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); + 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_sendmsg_do_redirect(struct sock *sk, int send, + struct sk_msg_buff *md, + int flags) +{ + struct smap_psock *psock; + struct scatterlist *sg; + int i, err, free = 0; + + sg = md->sg_data; + + 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(); + lock_sock(sk); + err = bpf_tcp_push(sk, send, md, flags, false); + release_sock(sk); + smap_release_sock(psock, sk); + if (unlikely(err)) + goto out; + return 0; +out_rcu: + rcu_read_unlock(); +out: + i = md->sg_start; + while (sg[i].length) { + free += sg[i].length; + put_page(sg_page(&sg[i])); + sg[i].length = 0; + i++; + if (i == MAX_SKB_FRAGS) + i = 0; + } + return free; +} + +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); + 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 (cork) { + free_start_sg(sk, m); + kfree(m); + m = NULL; + } + if (unlikely(err)) + *copied -= err; + else + psock->sg_size -= send; + break; + case __SK_DROP: + default: + free_bytes_sg(sk, send, m); + 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_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_table(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; + 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) + 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; + else + m = &md; + + /* 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 = &m->sg_data[m->sg_end]; + 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) { tcp_bpf_proto = tcp_prot; tcp_bpf_proto.close = bpf_tcp_close; + /* 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); } @@ -412,7 +1054,6 @@ static int smap_parse_func_strparser(struct strparser *strp, return rc; } - static int smap_read_sock_done(struct strparser *strp, int err) { return err; @@ -482,12 +1123,22 @@ static void smap_gc_work(struct work_struct *w) 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); + kfree(psock->cork); + } 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); } @@ -503,6 +1154,7 @@ static struct smap_psock *smap_init_psock(struct sock *sock, 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); @@ -711,10 +1363,11 @@ static int sock_map_ctx_update_elem(struct bpf_sock_ops_kern *skops, { struct bpf_stab *stab = container_of(map, struct bpf_stab, map); struct smap_psock_map_entry *e = NULL; - struct bpf_prog *verdict, *parse; + struct bpf_prog *verdict, *parse, *tx_msg; struct sock *osock, *sock; struct smap_psock *psock; u32 i = *(u32 *)key; + bool new = false; int err; if (unlikely(flags > BPF_EXIST)) @@ -737,6 +1390,7 @@ static int sock_map_ctx_update_elem(struct bpf_sock_ops_kern *skops, */ verdict = READ_ONCE(stab->bpf_verdict); parse = READ_ONCE(stab->bpf_parse); + tx_msg = READ_ONCE(stab->bpf_tx_msg); if (parse && verdict) { /* bpf prog refcnt may be zero if a concurrent attach operation @@ -755,6 +1409,17 @@ static int sock_map_ctx_update_elem(struct bpf_sock_ops_kern *skops, } } + if (tx_msg) { + tx_msg = bpf_prog_inc_not_zero(stab->bpf_tx_msg); + if (IS_ERR(tx_msg)) { + if (verdict) + bpf_prog_put(verdict); + if (parse) + bpf_prog_put(parse); + return PTR_ERR(tx_msg); + } + } + write_lock_bh(&sock->sk_callback_lock); psock = smap_psock_sk(sock); @@ -769,7 +1434,14 @@ static int sock_map_ctx_update_elem(struct bpf_sock_ops_kern *skops, err = -EBUSY; goto out_progs; } - refcount_inc(&psock->refcnt); + 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, stab); if (IS_ERR(psock)) { @@ -777,11 +1449,8 @@ static int sock_map_ctx_update_elem(struct bpf_sock_ops_kern *skops, goto out_progs; } - err = tcp_set_ulp_id(sock, TCP_ULP_BPF); - if (err) - goto out_progs; - set_bit(SMAP_TX_RUNNING, &psock->state); + new = true; } e = kzalloc(sizeof(*e), GFP_ATOMIC | __GFP_NOWARN); @@ -794,6 +1463,14 @@ static int sock_map_ctx_update_elem(struct bpf_sock_ops_kern *skops, /* 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) @@ -815,8 +1492,6 @@ static int sock_map_ctx_update_elem(struct bpf_sock_ops_kern *skops, struct smap_psock *opsock = smap_psock_sk(osock); write_lock_bh(&osock->sk_callback_lock); - if (osock != sock && parse) - smap_stop_sock(opsock, osock); smap_list_remove(opsock, &stab->sock_map[i]); smap_release_sock(opsock, osock); write_unlock_bh(&osock->sk_callback_lock); @@ -829,6 +1504,8 @@ out_progs: bpf_prog_put(verdict); if (parse) bpf_prog_put(parse); + if (tx_msg) + bpf_prog_put(tx_msg); write_unlock_bh(&sock->sk_callback_lock); kfree(e); return err; @@ -843,6 +1520,9 @@ int sock_map_prog(struct bpf_map *map, struct bpf_prog *prog, u32 type) return -EINVAL; switch (type) { + case BPF_SK_MSG_VERDICT: + orig = xchg(&stab->bpf_tx_msg, prog); + break; case BPF_SK_SKB_STREAM_PARSER: orig = xchg(&stab->bpf_parse, prog); break; @@ -904,6 +1584,10 @@ static void sock_map_release(struct bpf_map *map, struct file *map_file) orig = xchg(&stab->bpf_verdict, NULL); if (orig) bpf_prog_put(orig); + + orig = xchg(&stab->bpf_tx_msg, NULL); + if (orig) + bpf_prog_put(orig); } const struct bpf_map_ops sock_map_ops = { diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index e24aa3241387..3aeb4ea2a93a 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -1315,7 +1315,8 @@ static int bpf_obj_get(const union bpf_attr *attr) #define BPF_PROG_ATTACH_LAST_FIELD attach_flags -static int sockmap_get_from_fd(const union bpf_attr *attr, bool attach) +static int sockmap_get_from_fd(const union bpf_attr *attr, + int type, bool attach) { struct bpf_prog *prog = NULL; int ufd = attr->target_fd; @@ -1329,8 +1330,7 @@ static int sockmap_get_from_fd(const union bpf_attr *attr, bool attach) return PTR_ERR(map); if (attach) { - prog = bpf_prog_get_type(attr->attach_bpf_fd, - BPF_PROG_TYPE_SK_SKB); + prog = bpf_prog_get_type(attr->attach_bpf_fd, type); if (IS_ERR(prog)) { fdput(f); return PTR_ERR(prog); @@ -1382,9 +1382,11 @@ static int bpf_prog_attach(const union bpf_attr *attr) case BPF_CGROUP_DEVICE: ptype = BPF_PROG_TYPE_CGROUP_DEVICE; break; + case BPF_SK_MSG_VERDICT: + return sockmap_get_from_fd(attr, BPF_PROG_TYPE_SK_MSG, true); case BPF_SK_SKB_STREAM_PARSER: case BPF_SK_SKB_STREAM_VERDICT: - return sockmap_get_from_fd(attr, true); + return sockmap_get_from_fd(attr, BPF_PROG_TYPE_SK_SKB, true); default: return -EINVAL; } @@ -1437,9 +1439,11 @@ static int bpf_prog_detach(const union bpf_attr *attr) case BPF_CGROUP_DEVICE: ptype = BPF_PROG_TYPE_CGROUP_DEVICE; break; + case BPF_SK_MSG_VERDICT: + return sockmap_get_from_fd(attr, BPF_PROG_TYPE_SK_MSG, false); case BPF_SK_SKB_STREAM_PARSER: case BPF_SK_SKB_STREAM_VERDICT: - return sockmap_get_from_fd(attr, false); + return sockmap_get_from_fd(attr, BPF_PROG_TYPE_SK_SKB, false); default: return -EINVAL; } diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index eb79a34359c0..e9f7c20691c1 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -1248,6 +1248,7 @@ static bool may_access_direct_pkt_data(struct bpf_verifier_env *env, case BPF_PROG_TYPE_XDP: case BPF_PROG_TYPE_LWT_XMIT: case BPF_PROG_TYPE_SK_SKB: + case BPF_PROG_TYPE_SK_MSG: if (meta) return meta->pkt_access; @@ -2071,7 +2072,8 @@ static int check_map_func_compatibility(struct bpf_verifier_env *env, case BPF_MAP_TYPE_SOCKMAP: if (func_id != BPF_FUNC_sk_redirect_map && func_id != BPF_FUNC_sock_map_update && - func_id != BPF_FUNC_map_delete_elem) + func_id != BPF_FUNC_map_delete_elem && + func_id != BPF_FUNC_msg_redirect_map) goto error; break; default: @@ -2109,6 +2111,7 @@ static int check_map_func_compatibility(struct bpf_verifier_env *env, goto error; break; case BPF_FUNC_sk_redirect_map: + case BPF_FUNC_msg_redirect_map: if (map->map_type != BPF_MAP_TYPE_SOCKMAP) goto error; break; diff --git a/net/core/filter.c b/net/core/filter.c index 33edfa8372fd..2b6c47597eab 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -1890,6 +1890,44 @@ static const struct bpf_func_proto bpf_sk_redirect_map_proto = { .arg4_type = ARG_ANYTHING, }; +BPF_CALL_4(bpf_msg_redirect_map, struct sk_msg_buff *, msg, + struct bpf_map *, map, u32, key, u64, flags) +{ + /* If user passes invalid input drop the packet. */ + if (unlikely(flags)) + return SK_DROP; + + msg->key = key; + msg->flags = flags; + msg->map = map; + + return SK_PASS; +} + +struct sock *do_msg_redirect_map(struct sk_msg_buff *msg) +{ + struct sock *sk = NULL; + + if (msg->map) { + sk = __sock_map_lookup_elem(msg->map, msg->key); + + msg->key = 0; + msg->map = NULL; + } + + return sk; +} + +static const struct bpf_func_proto bpf_msg_redirect_map_proto = { + .func = bpf_msg_redirect_map, + .gpl_only = false, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_CTX, + .arg2_type = ARG_CONST_MAP_PTR, + .arg3_type = ARG_ANYTHING, + .arg4_type = ARG_ANYTHING, +}; + BPF_CALL_1(bpf_get_cgroup_classid, const struct sk_buff *, skb) { return task_get_classid(skb); @@ -3591,6 +3629,16 @@ static const struct bpf_func_proto * } } +static const struct bpf_func_proto *sk_msg_func_proto(enum bpf_func_id func_id) +{ + switch (func_id) { + case BPF_FUNC_msg_redirect_map: + return &bpf_msg_redirect_map_proto; + default: + return bpf_base_func_proto(func_id); + } +} + static const struct bpf_func_proto *sk_skb_func_proto(enum bpf_func_id func_id) { switch (func_id) { @@ -3980,6 +4028,32 @@ static bool sk_skb_is_valid_access(int off, int size, return bpf_skb_is_valid_access(off, size, type, info); } +static bool sk_msg_is_valid_access(int off, int size, + enum bpf_access_type type, + struct bpf_insn_access_aux *info) +{ + if (type == BPF_WRITE) + return false; + + switch (off) { + case offsetof(struct sk_msg_md, data): + info->reg_type = PTR_TO_PACKET; + break; + case offsetof(struct sk_msg_md, data_end): + info->reg_type = PTR_TO_PACKET_END; + break; + } + + if (off < 0 || off >= sizeof(struct sk_msg_md)) + return false; + if (off % size != 0) + return false; + if (size != sizeof(__u64)) + return false; + + return true; +} + static u32 bpf_convert_ctx_access(enum bpf_access_type type, const struct bpf_insn *si, struct bpf_insn *insn_buf, @@ -4778,6 +4852,29 @@ static u32 sk_skb_convert_ctx_access(enum bpf_access_type type, return insn - insn_buf; } +static u32 sk_msg_convert_ctx_access(enum bpf_access_type type, + const struct bpf_insn *si, + struct bpf_insn *insn_buf, + struct bpf_prog *prog, u32 *target_size) +{ + struct bpf_insn *insn = insn_buf; + + switch (si->off) { + case offsetof(struct sk_msg_md, data): + *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct sk_msg_buff, data), + si->dst_reg, si->src_reg, + offsetof(struct sk_msg_buff, data)); + break; + case offsetof(struct sk_msg_md, data_end): + *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct sk_msg_buff, data_end), + si->dst_reg, si->src_reg, + offsetof(struct sk_msg_buff, data_end)); + break; + } + + return insn - insn_buf; +} + const struct bpf_verifier_ops sk_filter_verifier_ops = { .get_func_proto = sk_filter_func_proto, .is_valid_access = sk_filter_is_valid_access, @@ -4868,6 +4965,15 @@ const struct bpf_verifier_ops sk_skb_verifier_ops = { const struct bpf_prog_ops sk_skb_prog_ops = { }; +const struct bpf_verifier_ops sk_msg_verifier_ops = { + .get_func_proto = sk_msg_func_proto, + .is_valid_access = sk_msg_is_valid_access, + .convert_ctx_access = sk_msg_convert_ctx_access, +}; + +const struct bpf_prog_ops sk_msg_prog_ops = { +}; + int sk_detach_filter(struct sock *sk) { int ret = -ENOENT; |
