diff options
Diffstat (limited to 'net/core')
| -rw-r--r-- | net/core/filter.c | 273 | ||||
| -rw-r--r-- | net/core/sock.c | 61 |
2 files changed, 333 insertions, 1 deletions
diff --git a/net/core/filter.c b/net/core/filter.c index 33edfa8372fd..c86f03fd9ea5 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -1890,6 +1890,202 @@ 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_2(bpf_msg_apply_bytes, struct sk_msg_buff *, msg, u32, bytes) +{ + msg->apply_bytes = bytes; + return 0; +} + +static const struct bpf_func_proto bpf_msg_apply_bytes_proto = { + .func = bpf_msg_apply_bytes, + .gpl_only = false, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_CTX, + .arg2_type = ARG_ANYTHING, +}; + +BPF_CALL_2(bpf_msg_cork_bytes, struct sk_msg_buff *, msg, u32, bytes) +{ + msg->cork_bytes = bytes; + return 0; +} + +static const struct bpf_func_proto bpf_msg_cork_bytes_proto = { + .func = bpf_msg_cork_bytes, + .gpl_only = false, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_CTX, + .arg2_type = ARG_ANYTHING, +}; + +BPF_CALL_4(bpf_msg_pull_data, + struct sk_msg_buff *, msg, u32, start, u32, end, u64, flags) +{ + unsigned int len = 0, offset = 0, copy = 0; + struct scatterlist *sg = msg->sg_data; + int first_sg, last_sg, i, shift; + unsigned char *p, *to, *from; + int bytes = end - start; + struct page *page; + + if (unlikely(flags || end <= start)) + return -EINVAL; + + /* First find the starting scatterlist element */ + i = msg->sg_start; + do { + len = sg[i].length; + offset += len; + if (start < offset + len) + break; + i++; + if (i == MAX_SKB_FRAGS) + i = 0; + } while (i != msg->sg_end); + + if (unlikely(start >= offset + len)) + return -EINVAL; + + if (!msg->sg_copy[i] && bytes <= len) + goto out; + + first_sg = i; + + /* At this point we need to linearize multiple scatterlist + * elements or a single shared page. Either way we need to + * copy into a linear buffer exclusively owned by BPF. Then + * place the buffer in the scatterlist and fixup the original + * entries by removing the entries now in the linear buffer + * and shifting the remaining entries. For now we do not try + * to copy partial entries to avoid complexity of running out + * of sg_entry slots. The downside is reading a single byte + * will copy the entire sg entry. + */ + do { + copy += sg[i].length; + i++; + if (i == MAX_SKB_FRAGS) + i = 0; + if (bytes < copy) + break; + } while (i != msg->sg_end); + last_sg = i; + + if (unlikely(copy < end - start)) + return -EINVAL; + + page = alloc_pages(__GFP_NOWARN | GFP_ATOMIC, get_order(copy)); + if (unlikely(!page)) + return -ENOMEM; + p = page_address(page); + offset = 0; + + i = first_sg; + do { + from = sg_virt(&sg[i]); + len = sg[i].length; + to = p + offset; + + memcpy(to, from, len); + offset += len; + sg[i].length = 0; + put_page(sg_page(&sg[i])); + + i++; + if (i == MAX_SKB_FRAGS) + i = 0; + } while (i != last_sg); + + sg[first_sg].length = copy; + sg_set_page(&sg[first_sg], page, copy, 0); + + /* To repair sg ring we need to shift entries. If we only + * had a single entry though we can just replace it and + * be done. Otherwise walk the ring and shift the entries. + */ + shift = last_sg - first_sg - 1; + if (!shift) + goto out; + + i = first_sg + 1; + do { + int move_from; + + if (i + shift >= MAX_SKB_FRAGS) + move_from = i + shift - MAX_SKB_FRAGS; + else + move_from = i + shift; + + if (move_from == msg->sg_end) + break; + + sg[i] = sg[move_from]; + sg[move_from].length = 0; + sg[move_from].page_link = 0; + sg[move_from].offset = 0; + + i++; + if (i == MAX_SKB_FRAGS) + i = 0; + } while (1); + msg->sg_end -= shift; + if (msg->sg_end < 0) + msg->sg_end += MAX_SKB_FRAGS; +out: + msg->data = sg_virt(&sg[i]) + start - offset; + msg->data_end = msg->data + bytes; + + return 0; +} + +static const struct bpf_func_proto bpf_msg_pull_data_proto = { + .func = bpf_msg_pull_data, + .gpl_only = false, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_CTX, + .arg2_type = ARG_ANYTHING, + .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); @@ -2831,7 +3027,8 @@ bool bpf_helper_changes_pkt_data(void *func) func == bpf_l3_csum_replace || func == bpf_l4_csum_replace || func == bpf_xdp_adjust_head || - func == bpf_xdp_adjust_meta) + func == bpf_xdp_adjust_meta || + func == bpf_msg_pull_data) return true; return false; @@ -3591,6 +3788,22 @@ 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; + case BPF_FUNC_msg_apply_bytes: + return &bpf_msg_apply_bytes_proto; + case BPF_FUNC_msg_cork_bytes: + return &bpf_msg_cork_bytes_proto; + case BPF_FUNC_msg_pull_data: + return &bpf_msg_pull_data_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 +4193,32 @@ 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 +5017,29 @@ 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 +5130,15 @@ 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; diff --git a/net/core/sock.c b/net/core/sock.c index a8962d912895..f704324d1219 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -2237,6 +2237,67 @@ bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag) } EXPORT_SYMBOL(sk_page_frag_refill); +int sk_alloc_sg(struct sock *sk, int len, struct scatterlist *sg, + int sg_start, int *sg_curr_index, unsigned int *sg_curr_size, + int first_coalesce) +{ + int sg_curr = *sg_curr_index, use = 0, rc = 0; + unsigned int size = *sg_curr_size; + struct page_frag *pfrag; + struct scatterlist *sge; + + len -= size; + pfrag = sk_page_frag(sk); + + while (len > 0) { + unsigned int orig_offset; + + if (!sk_page_frag_refill(sk, pfrag)) { + rc = -ENOMEM; + goto out; + } + + use = min_t(int, len, pfrag->size - pfrag->offset); + + if (!sk_wmem_schedule(sk, use)) { + rc = -ENOMEM; + goto out; + } + + sk_mem_charge(sk, use); + size += use; + orig_offset = pfrag->offset; + pfrag->offset += use; + + sge = sg + sg_curr - 1; + if (sg_curr > first_coalesce && sg_page(sg) == pfrag->page && + sg->offset + sg->length == orig_offset) { + sg->length += use; + } else { + sge = sg + sg_curr; + sg_unmark_end(sge); + sg_set_page(sge, pfrag->page, use, orig_offset); + get_page(pfrag->page); + sg_curr++; + + if (sg_curr == MAX_SKB_FRAGS) + sg_curr = 0; + + if (sg_curr == sg_start) { + rc = -ENOSPC; + break; + } + } + + len -= use; + } +out: + *sg_curr_size = size; + *sg_curr_index = sg_curr; + return rc; +} +EXPORT_SYMBOL(sk_alloc_sg); + static void __lock_sock(struct sock *sk) __releases(&sk->sk_lock.slock) __acquires(&sk->sk_lock.slock) |