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(I'm so sorry!) Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel os linux
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#include <linux/skmsg.h>#include <linux/skbuff.h>#include <linux/scatterlist.h>
#include <net/sock.h>#include <net/tcp.h>#include <trace/events/sock.h>
static bool sk_msg_try_coalesce_ok(struct sk_msg *msg, int elem_first_coalesce){ if (msg->sg.end > msg->sg.start && elem_first_coalesce < msg->sg.end) return true;
if (msg->sg.end < msg->sg.start && (elem_first_coalesce > msg->sg.start || elem_first_coalesce < msg->sg.end)) return true;
return false;}
int sk_msg_alloc(struct sock *sk, struct sk_msg *msg, int len, int elem_first_coalesce){ struct page_frag *pfrag = sk_page_frag(sk); u32 osize = msg->sg.size; int ret = 0;
len -= msg->sg.size; while (len > 0) { struct scatterlist *sge; u32 orig_offset; int use, i;
if (!sk_page_frag_refill(sk, pfrag)) { ret = -ENOMEM; goto msg_trim; }
orig_offset = pfrag->offset; use = min_t(int, len, pfrag->size - orig_offset); if (!sk_wmem_schedule(sk, use)) { ret = -ENOMEM; goto msg_trim; }
i = msg->sg.end; sk_msg_iter_var_prev(i); sge = &msg->sg.data[i];
if (sk_msg_try_coalesce_ok(msg, elem_first_coalesce) && sg_page(sge) == pfrag->page && sge->offset + sge->length == orig_offset) { sge->length += use; } else { if (sk_msg_full(msg)) { ret = -ENOSPC; break; }
sge = &msg->sg.data[msg->sg.end]; sg_unmark_end(sge); sg_set_page(sge, pfrag->page, use, orig_offset); __clear_bit(msg->sg.end, msg->sg.copy); get_page(pfrag->page); sk_msg_iter_next(msg, end); }
sk_mem_charge(sk, use); msg->sg.size += use; pfrag->offset += use; len -= use; }
return ret;
msg_trim: sk_msg_trim(sk, msg, osize); return ret;}EXPORT_SYMBOL_GPL(sk_msg_alloc);
int sk_msg_clone(struct sock *sk, struct sk_msg *dst, struct sk_msg *src, u32 off, u32 len){ int i = src->sg.start; struct scatterlist *sge = sk_msg_elem(src, i); struct scatterlist *sgd = NULL; u32 sge_len, sge_off;
while (off) { if (sge->length > off) break; off -= sge->length; sk_msg_iter_var_next(i); if (i == src->sg.end && off) return -ENOSPC; sge = sk_msg_elem(src, i); }
while (len) { sge_len = sge->length - off; if (sge_len > len) sge_len = len;
if (dst->sg.end) sgd = sk_msg_elem(dst, dst->sg.end - 1);
if (sgd && (sg_page(sge) == sg_page(sgd)) && (sg_virt(sge) + off == sg_virt(sgd) + sgd->length)) { sgd->length += sge_len; dst->sg.size += sge_len; } else if (!sk_msg_full(dst)) { sge_off = sge->offset + off; sk_msg_page_add(dst, sg_page(sge), sge_len, sge_off); } else { return -ENOSPC; }
off = 0; len -= sge_len; sk_mem_charge(sk, sge_len); sk_msg_iter_var_next(i); if (i == src->sg.end && len) return -ENOSPC; sge = sk_msg_elem(src, i); }
return 0;}EXPORT_SYMBOL_GPL(sk_msg_clone);
void sk_msg_return_zero(struct sock *sk, struct sk_msg *msg, int bytes){ int i = msg->sg.start;
do { struct scatterlist *sge = sk_msg_elem(msg, i);
if (bytes < sge->length) { sge->length -= bytes; sge->offset += bytes; sk_mem_uncharge(sk, bytes); break; }
sk_mem_uncharge(sk, sge->length); bytes -= sge->length; sge->length = 0; sge->offset = 0; sk_msg_iter_var_next(i); } while (bytes && i != msg->sg.end); msg->sg.start = i;}EXPORT_SYMBOL_GPL(sk_msg_return_zero);
void sk_msg_return(struct sock *sk, struct sk_msg *msg, int bytes){ int i = msg->sg.start;
do { struct scatterlist *sge = &msg->sg.data[i]; int uncharge = (bytes < sge->length) ? bytes : sge->length;
sk_mem_uncharge(sk, uncharge); bytes -= uncharge; sk_msg_iter_var_next(i); } while (i != msg->sg.end);}EXPORT_SYMBOL_GPL(sk_msg_return);
static int sk_msg_free_elem(struct sock *sk, struct sk_msg *msg, u32 i, bool charge){ struct scatterlist *sge = sk_msg_elem(msg, i); u32 len = sge->length;
/* When the skb owns the memory we free it from consume_skb path. */ if (!msg->skb) { if (charge) sk_mem_uncharge(sk, len); put_page(sg_page(sge)); } __clear_bit(i, msg->sg.copy); memset(sge, 0, sizeof(*sge)); return len;}
static int __sk_msg_free(struct sock *sk, struct sk_msg *msg, u32 i, bool charge){ struct scatterlist *sge = sk_msg_elem(msg, i); int freed = 0;
while (msg->sg.size) { msg->sg.size -= sge->length; freed += sk_msg_free_elem(sk, msg, i, charge); sk_msg_iter_var_next(i); sk_msg_check_to_free(msg, i, msg->sg.size); sge = sk_msg_elem(msg, i); } consume_skb(msg->skb); sk_msg_init(msg); return freed;}
int sk_msg_free_nocharge(struct sock *sk, struct sk_msg *msg){ return __sk_msg_free(sk, msg, msg->sg.start, false);}EXPORT_SYMBOL_GPL(sk_msg_free_nocharge);
int sk_msg_free(struct sock *sk, struct sk_msg *msg){ return __sk_msg_free(sk, msg, msg->sg.start, true);}EXPORT_SYMBOL_GPL(sk_msg_free);
static void __sk_msg_free_partial(struct sock *sk, struct sk_msg *msg, u32 bytes, bool charge){ struct scatterlist *sge; u32 i = msg->sg.start;
while (bytes) { sge = sk_msg_elem(msg, i); if (!sge->length) break; if (bytes < sge->length) { if (charge) sk_mem_uncharge(sk, bytes); sge->length -= bytes; sge->offset += bytes; msg->sg.size -= bytes; break; }
msg->sg.size -= sge->length; bytes -= sge->length; sk_msg_free_elem(sk, msg, i, charge); sk_msg_iter_var_next(i); sk_msg_check_to_free(msg, i, bytes); } msg->sg.start = i;}
void sk_msg_free_partial(struct sock *sk, struct sk_msg *msg, u32 bytes){ __sk_msg_free_partial(sk, msg, bytes, true);}EXPORT_SYMBOL_GPL(sk_msg_free_partial);
void sk_msg_free_partial_nocharge(struct sock *sk, struct sk_msg *msg, u32 bytes){ __sk_msg_free_partial(sk, msg, bytes, false);}
void sk_msg_trim(struct sock *sk, struct sk_msg *msg, int len){ int trim = msg->sg.size - len; u32 i = msg->sg.end;
if (trim <= 0) { WARN_ON(trim < 0); return; }
sk_msg_iter_var_prev(i); msg->sg.size = len; while (msg->sg.data[i].length && trim >= msg->sg.data[i].length) { trim -= msg->sg.data[i].length; sk_msg_free_elem(sk, msg, i, true); sk_msg_iter_var_prev(i); if (!trim) goto out; }
msg->sg.data[i].length -= trim; sk_mem_uncharge(sk, trim); /* Adjust copybreak if it falls into the trimmed part of last buf */ if (msg->sg.curr == i && msg->sg.copybreak > msg->sg.data[i].length) msg->sg.copybreak = msg->sg.data[i].length;out: sk_msg_iter_var_next(i); msg->sg.end = i;
/* If we trim data a full sg elem before curr pointer update * copybreak and current so that any future copy operations * start at new copy location. * However trimmed data that has not yet been used in a copy op * does not require an update. */ if (!msg->sg.size) { msg->sg.curr = msg->sg.start; msg->sg.copybreak = 0; } else if (sk_msg_iter_dist(msg->sg.start, msg->sg.curr) >= sk_msg_iter_dist(msg->sg.start, msg->sg.end)) { sk_msg_iter_var_prev(i); msg->sg.curr = i; msg->sg.copybreak = msg->sg.data[i].length; }}EXPORT_SYMBOL_GPL(sk_msg_trim);
int sk_msg_zerocopy_from_iter(struct sock *sk, struct iov_iter *from, struct sk_msg *msg, u32 bytes){ int i, maxpages, ret = 0, num_elems = sk_msg_elem_used(msg); const int to_max_pages = MAX_MSG_FRAGS; struct page *pages[MAX_MSG_FRAGS]; ssize_t orig, copied, use, offset;
orig = msg->sg.size; while (bytes > 0) { i = 0; maxpages = to_max_pages - num_elems; if (maxpages == 0) { ret = -EFAULT; goto out; }
copied = iov_iter_get_pages2(from, pages, bytes, maxpages, &offset); if (copied <= 0) { ret = -EFAULT; goto out; }
bytes -= copied; msg->sg.size += copied;
while (copied) { use = min_t(int, copied, PAGE_SIZE - offset); sg_set_page(&msg->sg.data[msg->sg.end], pages[i], use, offset); sg_unmark_end(&msg->sg.data[msg->sg.end]); sk_mem_charge(sk, use);
offset = 0; copied -= use; sk_msg_iter_next(msg, end); num_elems++; i++; } /* When zerocopy is mixed with sk_msg_*copy* operations we * may have a copybreak set in this case clear and prefer * zerocopy remainder when possible. */ msg->sg.copybreak = 0; msg->sg.curr = msg->sg.end; }out: /* Revert iov_iter updates, msg will need to use 'trim' later if it * also needs to be cleared. */ if (ret) iov_iter_revert(from, msg->sg.size - orig); return ret;}EXPORT_SYMBOL_GPL(sk_msg_zerocopy_from_iter);
int sk_msg_memcopy_from_iter(struct sock *sk, struct iov_iter *from, struct sk_msg *msg, u32 bytes){ int ret = -ENOSPC, i = msg->sg.curr; u32 copy, buf_size, copied = 0; struct scatterlist *sge; void *to;
do { sge = sk_msg_elem(msg, i); /* This is possible if a trim operation shrunk the buffer */ if (msg->sg.copybreak >= sge->length) { msg->sg.copybreak = 0; sk_msg_iter_var_next(i); if (i == msg->sg.end) break; sge = sk_msg_elem(msg, i); }
buf_size = sge->length - msg->sg.copybreak; copy = (buf_size > bytes) ? bytes : buf_size; to = sg_virt(sge) + msg->sg.copybreak; msg->sg.copybreak += copy; if (sk->sk_route_caps & NETIF_F_NOCACHE_COPY) ret = copy_from_iter_nocache(to, copy, from); else ret = copy_from_iter(to, copy, from); if (ret != copy) { ret = -EFAULT; goto out; } bytes -= copy; copied += copy; if (!bytes) break; msg->sg.copybreak = 0; sk_msg_iter_var_next(i); } while (i != msg->sg.end);out: msg->sg.curr = i; return (ret < 0) ? ret : copied;}EXPORT_SYMBOL_GPL(sk_msg_memcopy_from_iter);
int __sk_msg_recvmsg(struct sock *sk, struct sk_psock *psock, struct msghdr *msg, int len, int flags, int *copied_from_self){ struct iov_iter *iter = &msg->msg_iter; int peek = flags & MSG_PEEK; struct sk_msg *msg_rx; int i, copied = 0; bool from_self;
msg_rx = sk_psock_peek_msg(psock); if (copied_from_self) *copied_from_self = 0;
while (copied != len) { struct scatterlist *sge;
if (unlikely(!msg_rx)) break;
from_self = msg_rx->sk == sk; i = msg_rx->sg.start; do { struct page *page; int copy;
sge = sk_msg_elem(msg_rx, i); copy = sge->length; page = sg_page(sge); if (copied + copy > len) copy = len - copied; if (copy) copy = copy_page_to_iter(page, sge->offset, copy, iter); if (!copy) { copied = copied ? copied : -EFAULT; goto out; }
copied += copy; if (from_self && copied_from_self) *copied_from_self += copy;
if (likely(!peek)) { sge->offset += copy; sge->length -= copy; if (!msg_rx->skb) { sk_mem_uncharge(sk, copy); atomic_sub(copy, &sk->sk_rmem_alloc); } msg_rx->sg.size -= copy; sk_psock_msg_len_add(psock, -copy);
if (!sge->length) { sk_msg_iter_var_next(i); if (!msg_rx->skb) put_page(page); } } else { /* Lets not optimize peek case if copy_page_to_iter * didn't copy the entire length lets just break. */ if (copy != sge->length) goto out; sk_msg_iter_var_next(i); }
if (copied == len) break; } while ((i != msg_rx->sg.end) && !sg_is_last(sge));
if (unlikely(peek)) { msg_rx = sk_psock_next_msg(psock, msg_rx); if (!msg_rx) break; continue; }
msg_rx->sg.start = i; if (!sge->length && (i == msg_rx->sg.end || sg_is_last(sge))) { msg_rx = sk_psock_dequeue_msg(psock); kfree_sk_msg(msg_rx); } msg_rx = sk_psock_peek_msg(psock); }out: return copied;}
/* Receive sk_msg from psock->ingress_msg to @msg. */int sk_msg_recvmsg(struct sock *sk, struct sk_psock *psock, struct msghdr *msg, int len, int flags){ return __sk_msg_recvmsg(sk, psock, msg, len, flags, NULL);}EXPORT_SYMBOL_GPL(sk_msg_recvmsg);
bool sk_msg_is_readable(struct sock *sk){ struct sk_psock *psock; bool empty = true;
rcu_read_lock(); psock = sk_psock(sk); if (likely(psock)) empty = list_empty(&psock->ingress_msg); rcu_read_unlock(); return !empty;}EXPORT_SYMBOL_GPL(sk_msg_is_readable);
static struct sk_msg *alloc_sk_msg(gfp_t gfp){ struct sk_msg *msg;
msg = kzalloc_obj(*msg, gfp | __GFP_NOWARN); if (unlikely(!msg)) return NULL; sg_init_marker(msg->sg.data, NR_MSG_FRAG_IDS); return msg;}
static struct sk_msg *sk_psock_create_ingress_msg(struct sock *sk, struct sk_buff *skb){ if (atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf) return NULL;
if (!sk_rmem_schedule(sk, skb, skb->truesize)) return NULL;
return alloc_sk_msg(GFP_KERNEL);}
static int sk_psock_skb_ingress_enqueue(struct sk_buff *skb, u32 off, u32 len, struct sk_psock *psock, struct sock *sk, struct sk_msg *msg, bool take_ref){ int num_sge, copied;
/* skb_to_sgvec will fail when the total number of fragments in * frag_list and frags exceeds MAX_MSG_FRAGS. For example, the * caller may aggregate multiple skbs. */ num_sge = skb_to_sgvec(skb, msg->sg.data, off, len); if (num_sge < 0) { /* skb linearize may fail with ENOMEM, but lets simply try again * later if this happens. Under memory pressure we don't want to * drop the skb. We need to linearize the skb so that the mapping * in skb_to_sgvec can not error. * Note that skb_linearize requires the skb not to be shared. */ if (skb_linearize(skb)) return -EAGAIN;
num_sge = skb_to_sgvec(skb, msg->sg.data, off, len); if (unlikely(num_sge < 0)) return num_sge; }
#if IS_ENABLED(CONFIG_BPF_STREAM_PARSER) psock->ingress_bytes += len;#endif copied = len; msg->sg.start = 0; msg->sg.size = copied; msg->sg.end = num_sge; msg->skb = take_ref ? skb_get(skb) : skb;
sk_psock_queue_msg(psock, msg); sk_psock_data_ready(sk, psock); return copied;}
static int sk_psock_skb_ingress_self(struct sk_psock *psock, struct sk_buff *skb, u32 off, u32 len, bool take_ref);
static int sk_psock_skb_ingress(struct sk_psock *psock, struct sk_buff *skb, u32 off, u32 len){ struct sock *sk = psock->sk; struct sk_msg *msg; int err;
/* If we are receiving on the same sock skb->sk is already assigned, * skip memory accounting and owner transition seeing it already set * correctly. */ if (unlikely(skb->sk == sk)) return sk_psock_skb_ingress_self(psock, skb, off, len, true); msg = sk_psock_create_ingress_msg(sk, skb); if (!msg) return -EAGAIN;
/* This will transition ownership of the data from the socket where * the BPF program was run initiating the redirect to the socket * we will eventually receive this data on. The data will be released * from skb_consume found in __tcp_bpf_recvmsg() after its been copied * into user buffers. */ skb_set_owner_r(skb, sk); err = sk_psock_skb_ingress_enqueue(skb, off, len, psock, sk, msg, true); if (err < 0) kfree(msg); return err;}
/* Puts an skb on the ingress queue of the socket already assigned to the * skb. In this case we do not need to check memory limits or skb_set_owner_r * because the skb is already accounted for here. */static int sk_psock_skb_ingress_self(struct sk_psock *psock, struct sk_buff *skb, u32 off, u32 len, bool take_ref){ struct sk_msg *msg = alloc_sk_msg(GFP_ATOMIC); struct sock *sk = psock->sk; int err;
if (unlikely(!msg)) return -EAGAIN; skb_set_owner_r(skb, sk);
/* This is used in tcp_bpf_recvmsg_parser() to determine whether the * data originates from the socket's own protocol stack. No need to * refcount sk because msg's lifetime is bound to sk via the ingress_msg. */ msg->sk = sk; err = sk_psock_skb_ingress_enqueue(skb, off, len, psock, sk, msg, take_ref); if (err < 0) kfree(msg); return err;}
static int sk_psock_handle_skb(struct sk_psock *psock, struct sk_buff *skb, u32 off, u32 len, bool ingress){ if (!ingress) { if (!sock_writeable(psock->sk)) return -EAGAIN; return skb_send_sock(psock->sk, skb, off, len); }
return sk_psock_skb_ingress(psock, skb, off, len);}
static void sk_psock_skb_state(struct sk_psock *psock, struct sk_psock_work_state *state, int len, int off){ spin_lock_bh(&psock->ingress_lock); if (sk_psock_test_state(psock, SK_PSOCK_TX_ENABLED)) { state->len = len; state->off = off; } spin_unlock_bh(&psock->ingress_lock);}
static void sk_psock_backlog(struct work_struct *work){ struct delayed_work *dwork = to_delayed_work(work); struct sk_psock *psock = container_of(dwork, struct sk_psock, work); struct sk_psock_work_state *state = &psock->work_state; struct sk_buff *skb = NULL; u32 len = 0, off = 0; bool ingress; int ret;
/* If sk is quickly removed from the map and then added back, the old * psock should not be scheduled, because there are now two psocks * pointing to the same sk. */ if (!sk_psock_test_state(psock, SK_PSOCK_TX_ENABLED)) return;
/* Increment the psock refcnt to synchronize with close(fd) path in * sock_map_close(), ensuring we wait for backlog thread completion * before sk_socket freed. If refcnt increment fails, it indicates * sock_map_close() completed with sk_socket potentially already freed. */ if (!sk_psock_get(psock->sk)) return; mutex_lock(&psock->work_mutex); while ((skb = skb_peek(&psock->ingress_skb))) { len = skb->len; off = 0; if (skb_bpf_strparser(skb)) { struct strp_msg *stm = strp_msg(skb);
off = stm->offset; len = stm->full_len; }
/* Resume processing from previous partial state */ if (unlikely(state->len)) { len = state->len; off = state->off; }
ingress = skb_bpf_ingress(skb); skb_bpf_redirect_clear(skb); do { ret = -EIO; if (!sock_flag(psock->sk, SOCK_DEAD)) ret = sk_psock_handle_skb(psock, skb, off, len, ingress); if (ret <= 0) { if (ret == -EAGAIN) { sk_psock_skb_state(psock, state, len, off); /* Restore redir info we cleared before */ skb_bpf_set_redir(skb, psock->sk, ingress); /* Delay slightly to prioritize any * other work that might be here. */ if (sk_psock_test_state(psock, SK_PSOCK_TX_ENABLED)) schedule_delayed_work(&psock->work, 1); goto end; } /* Hard errors break pipe and stop xmit. */ sk_psock_report_error(psock, ret ? -ret : EPIPE); sk_psock_clear_state(psock, SK_PSOCK_TX_ENABLED); goto end; } off += ret; len -= ret; } while (len);
/* The entire skb sent, clear state */ sk_psock_skb_state(psock, state, 0, 0); skb = skb_dequeue(&psock->ingress_skb); kfree_skb(skb); }end: mutex_unlock(&psock->work_mutex); sk_psock_put(psock->sk, psock);}
struct sk_psock *sk_psock_init(struct sock *sk, int node){ struct sk_psock *psock; struct proto *prot;
write_lock_bh(&sk->sk_callback_lock);
if (sk_is_inet(sk) && inet_csk_has_ulp(sk)) { psock = ERR_PTR(-EINVAL); goto out; }
if (sk->sk_user_data) { psock = ERR_PTR(-EBUSY); goto out; }
psock = kzalloc_node(sizeof(*psock), GFP_ATOMIC | __GFP_NOWARN, node); if (!psock) { psock = ERR_PTR(-ENOMEM); goto out; }
prot = READ_ONCE(sk->sk_prot); psock->sk = sk; psock->eval = __SK_NONE; psock->sk_proto = prot; psock->saved_unhash = prot->unhash; psock->saved_destroy = prot->destroy; psock->saved_close = prot->close; psock->saved_write_space = sk->sk_write_space;
INIT_LIST_HEAD(&psock->link); spin_lock_init(&psock->link_lock);
INIT_DELAYED_WORK(&psock->work, sk_psock_backlog); mutex_init(&psock->work_mutex); INIT_LIST_HEAD(&psock->ingress_msg); spin_lock_init(&psock->ingress_lock); skb_queue_head_init(&psock->ingress_skb);
sk_psock_set_state(psock, SK_PSOCK_TX_ENABLED); refcount_set(&psock->refcnt, 1);
__rcu_assign_sk_user_data_with_flags(sk, psock, SK_USER_DATA_NOCOPY | SK_USER_DATA_PSOCK); sock_hold(sk);
out: write_unlock_bh(&sk->sk_callback_lock); return psock;}EXPORT_SYMBOL_GPL(sk_psock_init);
struct sk_psock_link *sk_psock_link_pop(struct sk_psock *psock){ struct sk_psock_link *link;
spin_lock_bh(&psock->link_lock); link = list_first_entry_or_null(&psock->link, struct sk_psock_link, list); if (link) list_del(&link->list); spin_unlock_bh(&psock->link_lock); return link;}
static void __sk_psock_purge_ingress_msg(struct sk_psock *psock){ struct sk_msg *msg, *tmp;
list_for_each_entry_safe(msg, tmp, &psock->ingress_msg, list) { list_del(&msg->list); if (!msg->skb) atomic_sub(msg->sg.size, &psock->sk->sk_rmem_alloc); sk_psock_msg_len_add(psock, -msg->sg.size); sk_msg_free(psock->sk, msg); kfree(msg); } WARN_ON_ONCE(psock->msg_tot_len);}
static void __sk_psock_zap_ingress(struct sk_psock *psock){ struct sk_buff *skb;
while ((skb = skb_dequeue(&psock->ingress_skb)) != NULL) { skb_bpf_redirect_clear(skb); sock_drop(psock->sk, skb); } __sk_psock_purge_ingress_msg(psock);}
static void sk_psock_link_destroy(struct sk_psock *psock){ struct sk_psock_link *link, *tmp;
list_for_each_entry_safe(link, tmp, &psock->link, list) { list_del(&link->list); sk_psock_free_link(link); }}
void sk_psock_stop(struct sk_psock *psock){ spin_lock_bh(&psock->ingress_lock); sk_psock_clear_state(psock, SK_PSOCK_TX_ENABLED); sk_psock_cork_free(psock); spin_unlock_bh(&psock->ingress_lock);}
static void sk_psock_done_strp(struct sk_psock *psock);
static void sk_psock_destroy(struct work_struct *work){ struct sk_psock *psock = container_of(to_rcu_work(work), struct sk_psock, rwork); /* No sk_callback_lock since already detached. */
sk_psock_done_strp(psock);
cancel_delayed_work_sync(&psock->work); __sk_psock_zap_ingress(psock); mutex_destroy(&psock->work_mutex);
psock_progs_drop(&psock->progs);
sk_psock_link_destroy(psock); sk_psock_cork_free(psock);
if (psock->sk_redir) sock_put(psock->sk_redir); if (psock->sk_pair) sock_put(psock->sk_pair); sock_put(psock->sk); kfree(psock);}
void sk_psock_drop(struct sock *sk, struct sk_psock *psock){ write_lock_bh(&sk->sk_callback_lock); sk_psock_restore_proto(sk, psock); rcu_assign_sk_user_data(sk, NULL); if (psock->progs.stream_parser) sk_psock_stop_strp(sk, psock); else if (psock->progs.stream_verdict || psock->progs.skb_verdict) sk_psock_stop_verdict(sk, psock); write_unlock_bh(&sk->sk_callback_lock);
sk_psock_stop(psock);
INIT_RCU_WORK(&psock->rwork, sk_psock_destroy); queue_rcu_work(system_percpu_wq, &psock->rwork);}EXPORT_SYMBOL_GPL(sk_psock_drop);
static int sk_psock_map_verd(int verdict, bool redir){ switch (verdict) { case SK_PASS: return redir ? __SK_REDIRECT : __SK_PASS; case SK_DROP: default: break; }
return __SK_DROP;}
int sk_psock_msg_verdict(struct sock *sk, struct sk_psock *psock, struct sk_msg *msg){ struct bpf_prog *prog; int ret;
rcu_read_lock(); prog = READ_ONCE(psock->progs.msg_parser); if (unlikely(!prog)) { ret = __SK_PASS; goto out; }
sk_msg_compute_data_pointers(msg); msg->sk = sk; ret = bpf_prog_run_pin_on_cpu(prog, msg); msg->sk = NULL; ret = sk_psock_map_verd(ret, msg->sk_redir); psock->apply_bytes = msg->apply_bytes; if (ret == __SK_REDIRECT) { if (psock->sk_redir) { sock_put(psock->sk_redir); psock->sk_redir = NULL; } if (!msg->sk_redir) { ret = __SK_DROP; goto out; } psock->redir_ingress = sk_msg_to_ingress(msg); psock->sk_redir = msg->sk_redir; sock_hold(psock->sk_redir); }out: rcu_read_unlock(); return ret;}EXPORT_SYMBOL_GPL(sk_psock_msg_verdict);
static int sk_psock_skb_redirect(struct sk_psock *from, struct sk_buff *skb){ struct sk_psock *psock_other; struct sock *sk_other;
sk_other = skb_bpf_redirect_fetch(skb); /* This error is a buggy BPF program, it returned a redirect * return code, but then didn't set a redirect interface. */ if (unlikely(!sk_other)) { skb_bpf_redirect_clear(skb); sock_drop(from->sk, skb); return -EIO; } psock_other = sk_psock(sk_other); /* This error indicates the socket is being torn down or had another * error that caused the pipe to break. We can't send a packet on * a socket that is in this state so we drop the skb. */ if (!psock_other || sock_flag(sk_other, SOCK_DEAD)) { skb_bpf_redirect_clear(skb); sock_drop(from->sk, skb); return -EIO; } spin_lock_bh(&psock_other->ingress_lock); if (!sk_psock_test_state(psock_other, SK_PSOCK_TX_ENABLED)) { spin_unlock_bh(&psock_other->ingress_lock); skb_bpf_redirect_clear(skb); sock_drop(from->sk, skb); return -EIO; }
skb_queue_tail(&psock_other->ingress_skb, skb); schedule_delayed_work(&psock_other->work, 0); spin_unlock_bh(&psock_other->ingress_lock); return 0;}
static int sk_psock_verdict_apply(struct sk_psock *psock, struct sk_buff *skb, int verdict){ struct sock *sk_other; int err = 0; u32 len, off;
if (verdict == __SK_REDIRECT && skb_bpf_ingress(skb) && skb_bpf_redirect_fetch(skb) == psock->sk) verdict = __SK_PASS;
switch (verdict) { case __SK_PASS: err = -EIO; sk_other = psock->sk; if (sock_flag(sk_other, SOCK_DEAD) || !sk_psock_test_state(psock, SK_PSOCK_TX_ENABLED)) goto out_free;
skb_bpf_set_ingress(skb);
/* If the queue is empty then we can submit directly * into the msg queue. If its not empty we have to * queue work otherwise we may get OOO data. Otherwise, * if sk_psock_skb_ingress errors will be handled by * retrying later from workqueue. */ if (skb_queue_empty(&psock->ingress_skb)) { len = skb->len; off = 0; if (skb_bpf_strparser(skb)) { struct strp_msg *stm = strp_msg(skb);
off = stm->offset; len = stm->full_len; } err = sk_psock_skb_ingress_self(psock, skb, off, len, false); } if (err < 0) { spin_lock_bh(&psock->ingress_lock); if (sk_psock_test_state(psock, SK_PSOCK_TX_ENABLED)) { skb_queue_tail(&psock->ingress_skb, skb); schedule_delayed_work(&psock->work, 0); err = 0; } spin_unlock_bh(&psock->ingress_lock); if (err < 0) goto out_free; } break; case __SK_REDIRECT: tcp_eat_skb(psock->sk, skb); err = sk_psock_skb_redirect(psock, skb); break; case __SK_DROP: default:out_free: skb_bpf_redirect_clear(skb); tcp_eat_skb(psock->sk, skb); sock_drop(psock->sk, skb); }
return err;}
static void sk_psock_write_space(struct sock *sk){ struct sk_psock *psock; void (*write_space)(struct sock *sk) = NULL;
rcu_read_lock(); psock = sk_psock(sk); if (likely(psock)) { if (sk_psock_test_state(psock, SK_PSOCK_TX_ENABLED)) schedule_delayed_work(&psock->work, 0); write_space = psock->saved_write_space; } rcu_read_unlock(); if (write_space) write_space(sk);}
#if IS_ENABLED(CONFIG_BPF_STREAM_PARSER)static void sk_psock_strp_read(struct strparser *strp, struct sk_buff *skb){ struct sk_psock *psock; struct bpf_prog *prog; int ret = __SK_DROP; struct sock *sk;
rcu_read_lock(); sk = strp->sk; psock = sk_psock(sk); if (unlikely(!psock)) { sock_drop(sk, skb); goto out; } prog = READ_ONCE(psock->progs.stream_verdict); if (likely(prog)) { skb->sk = sk; skb_dst_drop(skb); skb_bpf_redirect_clear(skb); ret = bpf_prog_run_pin_on_cpu(prog, skb); skb_bpf_set_strparser(skb); ret = sk_psock_map_verd(ret, skb_bpf_redirect_fetch(skb)); skb->sk = NULL; } sk_psock_verdict_apply(psock, skb, ret);out: rcu_read_unlock();}
static int sk_psock_strp_read_done(struct strparser *strp, int err){ return err;}
static int sk_psock_strp_parse(struct strparser *strp, struct sk_buff *skb){ struct sk_psock *psock = container_of(strp, struct sk_psock, strp); struct bpf_prog *prog; int ret = skb->len;
rcu_read_lock(); prog = READ_ONCE(psock->progs.stream_parser); if (likely(prog)) { skb->sk = psock->sk; ret = bpf_prog_run_pin_on_cpu(prog, skb); skb->sk = NULL; } rcu_read_unlock(); return ret;}
/* Called with socket lock held. */static void sk_psock_strp_data_ready(struct sock *sk){ struct sk_psock *psock;
trace_sk_data_ready(sk);
rcu_read_lock(); psock = sk_psock(sk); if (likely(psock)) { read_lock_bh(&sk->sk_callback_lock); strp_data_ready(&psock->strp); read_unlock_bh(&sk->sk_callback_lock); } rcu_read_unlock();}
int sk_psock_init_strp(struct sock *sk, struct sk_psock *psock){ int ret;
static const struct strp_callbacks cb = { .rcv_msg = sk_psock_strp_read, .read_sock_done = sk_psock_strp_read_done, .parse_msg = sk_psock_strp_parse, };
ret = strp_init(&psock->strp, sk, &cb); if (!ret) sk_psock_set_state(psock, SK_PSOCK_RX_STRP_ENABLED);
if (sk_is_tcp(sk)) { psock->strp.cb.read_sock = tcp_bpf_strp_read_sock; psock->copied_seq = tcp_sk(sk)->copied_seq; } return ret;}
void sk_psock_start_strp(struct sock *sk, struct sk_psock *psock){ if (psock->saved_data_ready) return;
psock->saved_data_ready = sk->sk_data_ready; WRITE_ONCE(sk->sk_data_ready, sk_psock_strp_data_ready); WRITE_ONCE(sk->sk_write_space, sk_psock_write_space);}
void sk_psock_stop_strp(struct sock *sk, struct sk_psock *psock){ psock_set_prog(&psock->progs.stream_parser, NULL);
if (!psock->saved_data_ready) return;
WRITE_ONCE(sk->sk_data_ready, psock->saved_data_ready); WRITE_ONCE(psock->saved_data_ready, NULL); strp_stop(&psock->strp);}
static void sk_psock_done_strp(struct sk_psock *psock){ /* Parser has been stopped */ if (sk_psock_test_state(psock, SK_PSOCK_RX_STRP_ENABLED)) strp_done(&psock->strp);}#elsestatic void sk_psock_done_strp(struct sk_psock *psock){}#endif /* CONFIG_BPF_STREAM_PARSER */
static int sk_psock_verdict_recv(struct sock *sk, struct sk_buff *skb){ struct sk_psock *psock; struct bpf_prog *prog; int ret = __SK_DROP; int len = skb->len;
rcu_read_lock(); psock = sk_psock(sk); if (unlikely(!psock)) { len = 0; tcp_eat_skb(sk, skb); sock_drop(sk, skb); goto out; } prog = READ_ONCE(psock->progs.stream_verdict); if (!prog) prog = READ_ONCE(psock->progs.skb_verdict); if (likely(prog)) { skb_dst_drop(skb); skb_bpf_redirect_clear(skb); ret = bpf_prog_run_pin_on_cpu(prog, skb); ret = sk_psock_map_verd(ret, skb_bpf_redirect_fetch(skb)); } ret = sk_psock_verdict_apply(psock, skb, ret); if (ret < 0) len = ret;out: rcu_read_unlock(); return len;}
static void sk_psock_verdict_data_ready(struct sock *sk){ const struct proto_ops *ops = NULL; struct sk_psock *psock; struct socket *sock; int copied;
trace_sk_data_ready(sk);
rcu_read_lock(); sock = READ_ONCE(sk->sk_socket); if (likely(sock)) ops = READ_ONCE(sock->ops); rcu_read_unlock(); if (!ops || !ops->read_skb) return;
copied = ops->read_skb(sk, sk_psock_verdict_recv); if (copied >= 0) { rcu_read_lock(); psock = sk_psock(sk); if (psock) sk_psock_data_ready(sk, psock); rcu_read_unlock(); }}
void sk_psock_start_verdict(struct sock *sk, struct sk_psock *psock){ if (psock->saved_data_ready) return;
psock->saved_data_ready = sk->sk_data_ready; WRITE_ONCE(sk->sk_data_ready, sk_psock_verdict_data_ready); WRITE_ONCE(sk->sk_write_space, sk_psock_write_space);}
void sk_psock_stop_verdict(struct sock *sk, struct sk_psock *psock){ psock_set_prog(&psock->progs.stream_verdict, NULL); psock_set_prog(&psock->progs.skb_verdict, NULL);
if (!psock->saved_data_ready) return;
WRITE_ONCE(sk->sk_data_ready, psock->saved_data_ready); psock->saved_data_ready = NULL;}