| /* |
| * Linux Socket Filter - Kernel level socket filtering |
| * |
| * Based on the design of the Berkeley Packet Filter. The new |
| * internal format has been designed by PLUMgrid: |
| * |
| * Copyright (c) 2011 - 2014 PLUMgrid, http://plumgrid.com |
| * |
| * Authors: |
| * |
| * Jay Schulist <jschlst@samba.org> |
| * Alexei Starovoitov <ast@plumgrid.com> |
| * Daniel Borkmann <dborkman@redhat.com> |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public License |
| * as published by the Free Software Foundation; either version |
| * 2 of the License, or (at your option) any later version. |
| * |
| * Andi Kleen - Fix a few bad bugs and races. |
| * Kris Katterjohn - Added many additional checks in bpf_check_classic() |
| */ |
| |
| #include <linux/module.h> |
| #include <linux/types.h> |
| #include <linux/mm.h> |
| #include <linux/fcntl.h> |
| #include <linux/socket.h> |
| #include <linux/in.h> |
| #include <linux/inet.h> |
| #include <linux/netdevice.h> |
| #include <linux/if_packet.h> |
| #include <linux/gfp.h> |
| #include <net/ip.h> |
| #include <net/protocol.h> |
| #include <net/netlink.h> |
| #include <linux/skbuff.h> |
| #include <net/sock.h> |
| #include <net/flow_dissector.h> |
| #include <linux/errno.h> |
| #include <linux/timer.h> |
| #include <asm/uaccess.h> |
| #include <asm/unaligned.h> |
| #include <linux/filter.h> |
| #include <linux/ratelimit.h> |
| #include <linux/seccomp.h> |
| #include <linux/if_vlan.h> |
| #include <linux/bpf.h> |
| #include <net/sch_generic.h> |
| #include <net/cls_cgroup.h> |
| #include <net/dst_metadata.h> |
| #include <net/dst.h> |
| #include <net/sock_reuseport.h> |
| |
| /** |
| * sk_filter_trim_cap - run a packet through a socket filter |
| * @sk: sock associated with &sk_buff |
| * @skb: buffer to filter |
| * @cap: limit on how short the eBPF program may trim the packet |
| * |
| * Run the eBPF program and then cut skb->data to correct size returned by |
| * the program. If pkt_len is 0 we toss packet. If skb->len is smaller |
| * than pkt_len we keep whole skb->data. This is the socket level |
| * wrapper to BPF_PROG_RUN. It returns 0 if the packet should |
| * be accepted or -EPERM if the packet should be tossed. |
| * |
| */ |
| int sk_filter_trim_cap(struct sock *sk, struct sk_buff *skb, unsigned int cap) |
| { |
| int err; |
| struct sk_filter *filter; |
| |
| /* |
| * If the skb was allocated from pfmemalloc reserves, only |
| * allow SOCK_MEMALLOC sockets to use it as this socket is |
| * helping free memory |
| */ |
| if (skb_pfmemalloc(skb) && !sock_flag(sk, SOCK_MEMALLOC)) |
| return -ENOMEM; |
| |
| err = security_sock_rcv_skb(sk, skb); |
| if (err) |
| return err; |
| |
| rcu_read_lock(); |
| filter = rcu_dereference(sk->sk_filter); |
| if (filter) { |
| unsigned int pkt_len = bpf_prog_run_save_cb(filter->prog, skb); |
| err = pkt_len ? pskb_trim(skb, max(cap, pkt_len)) : -EPERM; |
| } |
| rcu_read_unlock(); |
| |
| return err; |
| } |
| EXPORT_SYMBOL(sk_filter_trim_cap); |
| |
| static u64 __skb_get_pay_offset(u64 ctx, u64 a, u64 x, u64 r4, u64 r5) |
| { |
| return skb_get_poff((struct sk_buff *)(unsigned long) ctx); |
| } |
| |
| static u64 __skb_get_nlattr(u64 ctx, u64 a, u64 x, u64 r4, u64 r5) |
| { |
| struct sk_buff *skb = (struct sk_buff *)(unsigned long) ctx; |
| struct nlattr *nla; |
| |
| if (skb_is_nonlinear(skb)) |
| return 0; |
| |
| if (skb->len < sizeof(struct nlattr)) |
| return 0; |
| |
| if (a > skb->len - sizeof(struct nlattr)) |
| return 0; |
| |
| nla = nla_find((struct nlattr *) &skb->data[a], skb->len - a, x); |
| if (nla) |
| return (void *) nla - (void *) skb->data; |
| |
| return 0; |
| } |
| |
| static u64 __skb_get_nlattr_nest(u64 ctx, u64 a, u64 x, u64 r4, u64 r5) |
| { |
| struct sk_buff *skb = (struct sk_buff *)(unsigned long) ctx; |
| struct nlattr *nla; |
| |
| if (skb_is_nonlinear(skb)) |
| return 0; |
| |
| if (skb->len < sizeof(struct nlattr)) |
| return 0; |
| |
| if (a > skb->len - sizeof(struct nlattr)) |
| return 0; |
| |
| nla = (struct nlattr *) &skb->data[a]; |
| if (nla->nla_len > skb->len - a) |
| return 0; |
| |
| nla = nla_find_nested(nla, x); |
| if (nla) |
| return (void *) nla - (void *) skb->data; |
| |
| return 0; |
| } |
| |
| static u64 __get_raw_cpu_id(u64 ctx, u64 a, u64 x, u64 r4, u64 r5) |
| { |
| return raw_smp_processor_id(); |
| } |
| |
| static const struct bpf_func_proto bpf_get_raw_smp_processor_id_proto = { |
| .func = __get_raw_cpu_id, |
| .gpl_only = false, |
| .ret_type = RET_INTEGER, |
| }; |
| |
| static u32 convert_skb_access(int skb_field, int dst_reg, int src_reg, |
| struct bpf_insn *insn_buf) |
| { |
| struct bpf_insn *insn = insn_buf; |
| |
| switch (skb_field) { |
| case SKF_AD_MARK: |
| BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, mark) != 4); |
| |
| *insn++ = BPF_LDX_MEM(BPF_W, dst_reg, src_reg, |
| offsetof(struct sk_buff, mark)); |
| break; |
| |
| case SKF_AD_PKTTYPE: |
| *insn++ = BPF_LDX_MEM(BPF_B, dst_reg, src_reg, PKT_TYPE_OFFSET()); |
| *insn++ = BPF_ALU32_IMM(BPF_AND, dst_reg, PKT_TYPE_MAX); |
| #ifdef __BIG_ENDIAN_BITFIELD |
| *insn++ = BPF_ALU32_IMM(BPF_RSH, dst_reg, 5); |
| #endif |
| break; |
| |
| case SKF_AD_QUEUE: |
| BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, queue_mapping) != 2); |
| |
| *insn++ = BPF_LDX_MEM(BPF_H, dst_reg, src_reg, |
| offsetof(struct sk_buff, queue_mapping)); |
| break; |
| |
| case SKF_AD_VLAN_TAG: |
| case SKF_AD_VLAN_TAG_PRESENT: |
| BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, vlan_tci) != 2); |
| BUILD_BUG_ON(VLAN_TAG_PRESENT != 0x1000); |
| |
| /* dst_reg = *(u16 *) (src_reg + offsetof(vlan_tci)) */ |
| *insn++ = BPF_LDX_MEM(BPF_H, dst_reg, src_reg, |
| offsetof(struct sk_buff, vlan_tci)); |
| if (skb_field == SKF_AD_VLAN_TAG) { |
| *insn++ = BPF_ALU32_IMM(BPF_AND, dst_reg, |
| ~VLAN_TAG_PRESENT); |
| } else { |
| /* dst_reg >>= 12 */ |
| *insn++ = BPF_ALU32_IMM(BPF_RSH, dst_reg, 12); |
| /* dst_reg &= 1 */ |
| *insn++ = BPF_ALU32_IMM(BPF_AND, dst_reg, 1); |
| } |
| break; |
| } |
| |
| return insn - insn_buf; |
| } |
| |
| static bool convert_bpf_extensions(struct sock_filter *fp, |
| struct bpf_insn **insnp) |
| { |
| struct bpf_insn *insn = *insnp; |
| u32 cnt; |
| |
| switch (fp->k) { |
| case SKF_AD_OFF + SKF_AD_PROTOCOL: |
| BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, protocol) != 2); |
| |
| /* A = *(u16 *) (CTX + offsetof(protocol)) */ |
| *insn++ = BPF_LDX_MEM(BPF_H, BPF_REG_A, BPF_REG_CTX, |
| offsetof(struct sk_buff, protocol)); |
| /* A = ntohs(A) [emitting a nop or swap16] */ |
| *insn = BPF_ENDIAN(BPF_FROM_BE, BPF_REG_A, 16); |
| break; |
| |
| case SKF_AD_OFF + SKF_AD_PKTTYPE: |
| cnt = convert_skb_access(SKF_AD_PKTTYPE, BPF_REG_A, BPF_REG_CTX, insn); |
| insn += cnt - 1; |
| break; |
| |
| case SKF_AD_OFF + SKF_AD_IFINDEX: |
| case SKF_AD_OFF + SKF_AD_HATYPE: |
| BUILD_BUG_ON(FIELD_SIZEOF(struct net_device, ifindex) != 4); |
| BUILD_BUG_ON(FIELD_SIZEOF(struct net_device, type) != 2); |
| BUILD_BUG_ON(bytes_to_bpf_size(FIELD_SIZEOF(struct sk_buff, dev)) < 0); |
| |
| *insn++ = BPF_LDX_MEM(bytes_to_bpf_size(FIELD_SIZEOF(struct sk_buff, dev)), |
| BPF_REG_TMP, BPF_REG_CTX, |
| offsetof(struct sk_buff, dev)); |
| /* if (tmp != 0) goto pc + 1 */ |
| *insn++ = BPF_JMP_IMM(BPF_JNE, BPF_REG_TMP, 0, 1); |
| *insn++ = BPF_EXIT_INSN(); |
| if (fp->k == SKF_AD_OFF + SKF_AD_IFINDEX) |
| *insn = BPF_LDX_MEM(BPF_W, BPF_REG_A, BPF_REG_TMP, |
| offsetof(struct net_device, ifindex)); |
| else |
| *insn = BPF_LDX_MEM(BPF_H, BPF_REG_A, BPF_REG_TMP, |
| offsetof(struct net_device, type)); |
| break; |
| |
| case SKF_AD_OFF + SKF_AD_MARK: |
| cnt = convert_skb_access(SKF_AD_MARK, BPF_REG_A, BPF_REG_CTX, insn); |
| insn += cnt - 1; |
| break; |
| |
| case SKF_AD_OFF + SKF_AD_RXHASH: |
| BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, hash) != 4); |
| |
| *insn = BPF_LDX_MEM(BPF_W, BPF_REG_A, BPF_REG_CTX, |
| offsetof(struct sk_buff, hash)); |
| break; |
| |
| case SKF_AD_OFF + SKF_AD_QUEUE: |
| cnt = convert_skb_access(SKF_AD_QUEUE, BPF_REG_A, BPF_REG_CTX, insn); |
| insn += cnt - 1; |
| break; |
| |
| case SKF_AD_OFF + SKF_AD_VLAN_TAG: |
| cnt = convert_skb_access(SKF_AD_VLAN_TAG, |
| BPF_REG_A, BPF_REG_CTX, insn); |
| insn += cnt - 1; |
| break; |
| |
| case SKF_AD_OFF + SKF_AD_VLAN_TAG_PRESENT: |
| cnt = convert_skb_access(SKF_AD_VLAN_TAG_PRESENT, |
| BPF_REG_A, BPF_REG_CTX, insn); |
| insn += cnt - 1; |
| break; |
| |
| case SKF_AD_OFF + SKF_AD_VLAN_TPID: |
| BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, vlan_proto) != 2); |
| |
| /* A = *(u16 *) (CTX + offsetof(vlan_proto)) */ |
| *insn++ = BPF_LDX_MEM(BPF_H, BPF_REG_A, BPF_REG_CTX, |
| offsetof(struct sk_buff, vlan_proto)); |
| /* A = ntohs(A) [emitting a nop or swap16] */ |
| *insn = BPF_ENDIAN(BPF_FROM_BE, BPF_REG_A, 16); |
| break; |
| |
| case SKF_AD_OFF + SKF_AD_PAY_OFFSET: |
| case SKF_AD_OFF + SKF_AD_NLATTR: |
| case SKF_AD_OFF + SKF_AD_NLATTR_NEST: |
| case SKF_AD_OFF + SKF_AD_CPU: |
| case SKF_AD_OFF + SKF_AD_RANDOM: |
| /* arg1 = CTX */ |
| *insn++ = BPF_MOV64_REG(BPF_REG_ARG1, BPF_REG_CTX); |
| /* arg2 = A */ |
| *insn++ = BPF_MOV64_REG(BPF_REG_ARG2, BPF_REG_A); |
| /* arg3 = X */ |
| *insn++ = BPF_MOV64_REG(BPF_REG_ARG3, BPF_REG_X); |
| /* Emit call(arg1=CTX, arg2=A, arg3=X) */ |
| switch (fp->k) { |
| case SKF_AD_OFF + SKF_AD_PAY_OFFSET: |
| *insn = BPF_EMIT_CALL(__skb_get_pay_offset); |
| break; |
| case SKF_AD_OFF + SKF_AD_NLATTR: |
| *insn = BPF_EMIT_CALL(__skb_get_nlattr); |
| break; |
| case SKF_AD_OFF + SKF_AD_NLATTR_NEST: |
| *insn = BPF_EMIT_CALL(__skb_get_nlattr_nest); |
| break; |
| case SKF_AD_OFF + SKF_AD_CPU: |
| *insn = BPF_EMIT_CALL(__get_raw_cpu_id); |
| break; |
| case SKF_AD_OFF + SKF_AD_RANDOM: |
| *insn = BPF_EMIT_CALL(bpf_user_rnd_u32); |
| bpf_user_rnd_init_once(); |
| break; |
| } |
| break; |
| |
| case SKF_AD_OFF + SKF_AD_ALU_XOR_X: |
| /* A ^= X */ |
| *insn = BPF_ALU32_REG(BPF_XOR, BPF_REG_A, BPF_REG_X); |
| break; |
| |
| default: |
| /* This is just a dummy call to avoid letting the compiler |
| * evict __bpf_call_base() as an optimization. Placed here |
| * where no-one bothers. |
| */ |
| BUG_ON(__bpf_call_base(0, 0, 0, 0, 0) != 0); |
| return false; |
| } |
| |
| *insnp = insn; |
| return true; |
| } |
| |
| /** |
| * bpf_convert_filter - convert filter program |
| * @prog: the user passed filter program |
| * @len: the length of the user passed filter program |
| * @new_prog: buffer where converted program will be stored |
| * @new_len: pointer to store length of converted program |
| * |
| * Remap 'sock_filter' style BPF instruction set to 'sock_filter_ext' style. |
| * Conversion workflow: |
| * |
| * 1) First pass for calculating the new program length: |
| * bpf_convert_filter(old_prog, old_len, NULL, &new_len) |
| * |
| * 2) 2nd pass to remap in two passes: 1st pass finds new |
| * jump offsets, 2nd pass remapping: |
| * new_prog = kmalloc(sizeof(struct bpf_insn) * new_len); |
| * bpf_convert_filter(old_prog, old_len, new_prog, &new_len); |
| */ |
| static int bpf_convert_filter(struct sock_filter *prog, int len, |
| struct bpf_insn *new_prog, int *new_len) |
| { |
| int new_flen = 0, pass = 0, target, i; |
| struct bpf_insn *new_insn; |
| struct sock_filter *fp; |
| int *addrs = NULL; |
| u8 bpf_src; |
| |
| BUILD_BUG_ON(BPF_MEMWORDS * sizeof(u32) > MAX_BPF_STACK); |
| BUILD_BUG_ON(BPF_REG_FP + 1 != MAX_BPF_REG); |
| |
| if (len <= 0 || len > BPF_MAXINSNS) |
| return -EINVAL; |
| |
| if (new_prog) { |
| addrs = kcalloc(len, sizeof(*addrs), |
| GFP_KERNEL | __GFP_NOWARN); |
| if (!addrs) |
| return -ENOMEM; |
| } |
| |
| do_pass: |
| new_insn = new_prog; |
| fp = prog; |
| |
| /* Classic BPF related prologue emission. */ |
| if (new_insn) { |
| /* Classic BPF expects A and X to be reset first. These need |
| * to be guaranteed to be the first two instructions. |
| */ |
| *new_insn++ = BPF_ALU64_REG(BPF_XOR, BPF_REG_A, BPF_REG_A); |
| *new_insn++ = BPF_ALU64_REG(BPF_XOR, BPF_REG_X, BPF_REG_X); |
| |
| /* All programs must keep CTX in callee saved BPF_REG_CTX. |
| * In eBPF case it's done by the compiler, here we need to |
| * do this ourself. Initial CTX is present in BPF_REG_ARG1. |
| */ |
| *new_insn++ = BPF_MOV64_REG(BPF_REG_CTX, BPF_REG_ARG1); |
| } else { |
| new_insn += 3; |
| } |
| |
| for (i = 0; i < len; fp++, i++) { |
| struct bpf_insn tmp_insns[6] = { }; |
| struct bpf_insn *insn = tmp_insns; |
| |
| if (addrs) |
| addrs[i] = new_insn - new_prog; |
| |
| switch (fp->code) { |
| /* All arithmetic insns and skb loads map as-is. */ |
| case BPF_ALU | BPF_ADD | BPF_X: |
| case BPF_ALU | BPF_ADD | BPF_K: |
| case BPF_ALU | BPF_SUB | BPF_X: |
| case BPF_ALU | BPF_SUB | BPF_K: |
| case BPF_ALU | BPF_AND | BPF_X: |
| case BPF_ALU | BPF_AND | BPF_K: |
| case BPF_ALU | BPF_OR | BPF_X: |
| case BPF_ALU | BPF_OR | BPF_K: |
| case BPF_ALU | BPF_LSH | BPF_X: |
| case BPF_ALU | BPF_LSH | BPF_K: |
| case BPF_ALU | BPF_RSH | BPF_X: |
| case BPF_ALU | BPF_RSH | BPF_K: |
| case BPF_ALU | BPF_XOR | BPF_X: |
| case BPF_ALU | BPF_XOR | BPF_K: |
| case BPF_ALU | BPF_MUL | BPF_X: |
| case BPF_ALU | BPF_MUL | BPF_K: |
| case BPF_ALU | BPF_DIV | BPF_X: |
| case BPF_ALU | BPF_DIV | BPF_K: |
| case BPF_ALU | BPF_MOD | BPF_X: |
| case BPF_ALU | BPF_MOD | BPF_K: |
| case BPF_ALU | BPF_NEG: |
| case BPF_LD | BPF_ABS | BPF_W: |
| case BPF_LD | BPF_ABS | BPF_H: |
| case BPF_LD | BPF_ABS | BPF_B: |
| case BPF_LD | BPF_IND | BPF_W: |
| case BPF_LD | BPF_IND | BPF_H: |
| case BPF_LD | BPF_IND | BPF_B: |
| /* Check for overloaded BPF extension and |
| * directly convert it if found, otherwise |
| * just move on with mapping. |
| */ |
| if (BPF_CLASS(fp->code) == BPF_LD && |
| BPF_MODE(fp->code) == BPF_ABS && |
| convert_bpf_extensions(fp, &insn)) |
| break; |
| |
| *insn = BPF_RAW_INSN(fp->code, BPF_REG_A, BPF_REG_X, 0, fp->k); |
| break; |
| |
| /* Jump transformation cannot use BPF block macros |
| * everywhere as offset calculation and target updates |
| * require a bit more work than the rest, i.e. jump |
| * opcodes map as-is, but offsets need adjustment. |
| */ |
| |
| #define BPF_EMIT_JMP \ |
| do { \ |
| if (target >= len || target < 0) \ |
| goto err; \ |
| insn->off = addrs ? addrs[target] - addrs[i] - 1 : 0; \ |
| /* Adjust pc relative offset for 2nd or 3rd insn. */ \ |
| insn->off -= insn - tmp_insns; \ |
| } while (0) |
| |
| case BPF_JMP | BPF_JA: |
| target = i + fp->k + 1; |
| insn->code = fp->code; |
| BPF_EMIT_JMP; |
| break; |
| |
| case BPF_JMP | BPF_JEQ | BPF_K: |
| case BPF_JMP | BPF_JEQ | BPF_X: |
| case BPF_JMP | BPF_JSET | BPF_K: |
| case BPF_JMP | BPF_JSET | BPF_X: |
| case BPF_JMP | BPF_JGT | BPF_K: |
| case BPF_JMP | BPF_JGT | BPF_X: |
| case BPF_JMP | BPF_JGE | BPF_K: |
| case BPF_JMP | BPF_JGE | BPF_X: |
| if (BPF_SRC(fp->code) == BPF_K && (int) fp->k < 0) { |
| /* BPF immediates are signed, zero extend |
| * immediate into tmp register and use it |
| * in compare insn. |
| */ |
| *insn++ = BPF_MOV32_IMM(BPF_REG_TMP, fp->k); |
| |
| insn->dst_reg = BPF_REG_A; |
| insn->src_reg = BPF_REG_TMP; |
| bpf_src = BPF_X; |
| } else { |
| insn->dst_reg = BPF_REG_A; |
| insn->imm = fp->k; |
| bpf_src = BPF_SRC(fp->code); |
| insn->src_reg = bpf_src == BPF_X ? BPF_REG_X : 0; |
| } |
| |
| /* Common case where 'jump_false' is next insn. */ |
| if (fp->jf == 0) { |
| insn->code = BPF_JMP | BPF_OP(fp->code) | bpf_src; |
| target = i + fp->jt + 1; |
| BPF_EMIT_JMP; |
| break; |
| } |
| |
| /* Convert JEQ into JNE when 'jump_true' is next insn. */ |
| if (fp->jt == 0 && BPF_OP(fp->code) == BPF_JEQ) { |
| insn->code = BPF_JMP | BPF_JNE | bpf_src; |
| target = i + fp->jf + 1; |
| BPF_EMIT_JMP; |
| break; |
| } |
| |
| /* Other jumps are mapped into two insns: Jxx and JA. */ |
| target = i + fp->jt + 1; |
| insn->code = BPF_JMP | BPF_OP(fp->code) | bpf_src; |
| BPF_EMIT_JMP; |
| insn++; |
| |
| insn->code = BPF_JMP | BPF_JA; |
| target = i + fp->jf + 1; |
| BPF_EMIT_JMP; |
| break; |
| |
| /* ldxb 4 * ([14] & 0xf) is remaped into 6 insns. */ |
| case BPF_LDX | BPF_MSH | BPF_B: |
| /* tmp = A */ |
| *insn++ = BPF_MOV64_REG(BPF_REG_TMP, BPF_REG_A); |
| /* A = BPF_R0 = *(u8 *) (skb->data + K) */ |
| *insn++ = BPF_LD_ABS(BPF_B, fp->k); |
| /* A &= 0xf */ |
| *insn++ = BPF_ALU32_IMM(BPF_AND, BPF_REG_A, 0xf); |
| /* A <<= 2 */ |
| *insn++ = BPF_ALU32_IMM(BPF_LSH, BPF_REG_A, 2); |
| /* X = A */ |
| *insn++ = BPF_MOV64_REG(BPF_REG_X, BPF_REG_A); |
| /* A = tmp */ |
| *insn = BPF_MOV64_REG(BPF_REG_A, BPF_REG_TMP); |
| break; |
| |
| /* RET_K is remaped into 2 insns. RET_A case doesn't need an |
| * extra mov as BPF_REG_0 is already mapped into BPF_REG_A. |
| */ |
| case BPF_RET | BPF_A: |
| case BPF_RET | BPF_K: |
| if (BPF_RVAL(fp->code) == BPF_K) |
| *insn++ = BPF_MOV32_RAW(BPF_K, BPF_REG_0, |
| 0, fp->k); |
| *insn = BPF_EXIT_INSN(); |
| break; |
| |
| /* Store to stack. */ |
| case BPF_ST: |
| case BPF_STX: |
| *insn = BPF_STX_MEM(BPF_W, BPF_REG_FP, BPF_CLASS(fp->code) == |
| BPF_ST ? BPF_REG_A : BPF_REG_X, |
| -(BPF_MEMWORDS - fp->k) * 4); |
| break; |
| |
| /* Load from stack. */ |
| case BPF_LD | BPF_MEM: |
| case BPF_LDX | BPF_MEM: |
| *insn = BPF_LDX_MEM(BPF_W, BPF_CLASS(fp->code) == BPF_LD ? |
| BPF_REG_A : BPF_REG_X, BPF_REG_FP, |
| -(BPF_MEMWORDS - fp->k) * 4); |
| break; |
| |
| /* A = K or X = K */ |
| case BPF_LD | BPF_IMM: |
| case BPF_LDX | BPF_IMM: |
| *insn = BPF_MOV32_IMM(BPF_CLASS(fp->code) == BPF_LD ? |
| BPF_REG_A : BPF_REG_X, fp->k); |
| break; |
| |
| /* X = A */ |
| case BPF_MISC | BPF_TAX: |
| *insn = BPF_MOV64_REG(BPF_REG_X, BPF_REG_A); |
| break; |
| |
| /* A = X */ |
| case BPF_MISC | BPF_TXA: |
| *insn = BPF_MOV64_REG(BPF_REG_A, BPF_REG_X); |
| break; |
| |
| /* A = skb->len or X = skb->len */ |
| case BPF_LD | BPF_W | BPF_LEN: |
| case BPF_LDX | BPF_W | BPF_LEN: |
| *insn = BPF_LDX_MEM(BPF_W, BPF_CLASS(fp->code) == BPF_LD ? |
| BPF_REG_A : BPF_REG_X, BPF_REG_CTX, |
| offsetof(struct sk_buff, len)); |
| break; |
| |
| /* Access seccomp_data fields. */ |
| case BPF_LDX | BPF_ABS | BPF_W: |
| /* A = *(u32 *) (ctx + K) */ |
| *insn = BPF_LDX_MEM(BPF_W, BPF_REG_A, BPF_REG_CTX, fp->k); |
| break; |
| |
| /* Unknown instruction. */ |
| default: |
| goto err; |
| } |
| |
| insn++; |
| if (new_prog) |
| memcpy(new_insn, tmp_insns, |
| sizeof(*insn) * (insn - tmp_insns)); |
| new_insn += insn - tmp_insns; |
| } |
| |
| if (!new_prog) { |
| /* Only calculating new length. */ |
| *new_len = new_insn - new_prog; |
| return 0; |
| } |
| |
| pass++; |
| if (new_flen != new_insn - new_prog) { |
| new_flen = new_insn - new_prog; |
| if (pass > 2) |
| goto err; |
| goto do_pass; |
| } |
| |
| kfree(addrs); |
| BUG_ON(*new_len != new_flen); |
| return 0; |
| err: |
| kfree(addrs); |
| return -EINVAL; |
| } |
| |
| /* Security: |
| * |
| * As we dont want to clear mem[] array for each packet going through |
| * __bpf_prog_run(), we check that filter loaded by user never try to read |
| * a cell if not previously written, and we check all branches to be sure |
| * a malicious user doesn't try to abuse us. |
| */ |
| static int check_load_and_stores(const struct sock_filter *filter, int flen) |
| { |
| u16 *masks, memvalid = 0; /* One bit per cell, 16 cells */ |
| int pc, ret = 0; |
| |
| BUILD_BUG_ON(BPF_MEMWORDS > 16); |
| |
| masks = kmalloc_array(flen, sizeof(*masks), GFP_KERNEL); |
| if (!masks) |
| return -ENOMEM; |
| |
| memset(masks, 0xff, flen * sizeof(*masks)); |
| |
| for (pc = 0; pc < flen; pc++) { |
| memvalid &= masks[pc]; |
| |
| switch (filter[pc].code) { |
| case BPF_ST: |
| case BPF_STX: |
| memvalid |= (1 << filter[pc].k); |
| break; |
| case BPF_LD | BPF_MEM: |
| case BPF_LDX | BPF_MEM: |
| if (!(memvalid & (1 << filter[pc].k))) { |
| ret = -EINVAL; |
| goto error; |
| } |
| break; |
| case BPF_JMP | BPF_JA: |
| /* A jump must set masks on target */ |
| masks[pc + 1 + filter[pc].k] &= memvalid; |
| memvalid = ~0; |
| break; |
| case BPF_JMP | BPF_JEQ | BPF_K: |
| case BPF_JMP | BPF_JEQ | BPF_X: |
| case BPF_JMP | BPF_JGE | BPF_K: |
| case BPF_JMP | BPF_JGE | BPF_X: |
| case BPF_JMP | BPF_JGT | BPF_K: |
| case BPF_JMP | BPF_JGT | BPF_X: |
| case BPF_JMP | BPF_JSET | BPF_K: |
| case BPF_JMP | BPF_JSET | BPF_X: |
| /* A jump must set masks on targets */ |
| masks[pc + 1 + filter[pc].jt] &= memvalid; |
| masks[pc + 1 + filter[pc].jf] &= memvalid; |
| memvalid = ~0; |
| break; |
| } |
| } |
| error: |
| kfree(masks); |
| return ret; |
| } |
| |
| static bool chk_code_allowed(u16 code_to_probe) |
| { |
| static const bool codes[] = { |
| /* 32 bit ALU operations */ |
| [BPF_ALU | BPF_ADD | BPF_K] = true, |
| [BPF_ALU | BPF_ADD | BPF_X] = true, |
| [BPF_ALU | BPF_SUB | BPF_K] = true, |
| [BPF_ALU | BPF_SUB | BPF_X] = true, |
| [BPF_ALU | BPF_MUL | BPF_K] = true, |
| [BPF_ALU | BPF_MUL | BPF_X] = true, |
| [BPF_ALU | BPF_DIV | BPF_K] = true, |
| [BPF_ALU | BPF_DIV | BPF_X] = true, |
| [BPF_ALU | BPF_MOD | BPF_K] = true, |
| [BPF_ALU | BPF_MOD | BPF_X] = true, |
| [BPF_ALU | BPF_AND | BPF_K] = true, |
| [BPF_ALU | BPF_AND | BPF_X] = true, |
| [BPF_ALU | BPF_OR | BPF_K] = true, |
| [BPF_ALU | BPF_OR | BPF_X] = true, |
| [BPF_ALU | BPF_XOR | BPF_K] = true, |
| [BPF_ALU | BPF_XOR | BPF_X] = true, |
| [BPF_ALU | BPF_LSH | BPF_K] = true, |
| [BPF_ALU | BPF_LSH | BPF_X] = true, |
| [BPF_ALU | BPF_RSH | BPF_K] = true, |
| [BPF_ALU | BPF_RSH | BPF_X] = true, |
| [BPF_ALU | BPF_NEG] = true, |
| /* Load instructions */ |
| [BPF_LD | BPF_W | BPF_ABS] = true, |
| [BPF_LD | BPF_H | BPF_ABS] = true, |
| [BPF_LD | BPF_B | BPF_ABS] = true, |
| [BPF_LD | BPF_W | BPF_LEN] = true, |
| [BPF_LD | BPF_W | BPF_IND] = true, |
| [BPF_LD | BPF_H | BPF_IND] = true, |
| [BPF_LD | BPF_B | BPF_IND] = true, |
| [BPF_LD | BPF_IMM] = true, |
| [BPF_LD | BPF_MEM] = true, |
| [BPF_LDX | BPF_W | BPF_LEN] = true, |
| [BPF_LDX | BPF_B | BPF_MSH] = true, |
| [BPF_LDX | BPF_IMM] = true, |
| [BPF_LDX | BPF_MEM] = true, |
| /* Store instructions */ |
| [BPF_ST] = true, |
| [BPF_STX] = true, |
| /* Misc instructions */ |
| [BPF_MISC | BPF_TAX] = true, |
| [BPF_MISC | BPF_TXA] = true, |
| /* Return instructions */ |
| [BPF_RET | BPF_K] = true, |
| [BPF_RET | BPF_A] = true, |
| /* Jump instructions */ |
| [BPF_JMP | BPF_JA] = true, |
| [BPF_JMP | BPF_JEQ | BPF_K] = true, |
| [BPF_JMP | BPF_JEQ | BPF_X] = true, |
| [BPF_JMP | BPF_JGE | BPF_K] = true, |
| [BPF_JMP | BPF_JGE | BPF_X] = true, |
| [BPF_JMP | BPF_JGT | BPF_K] = true, |
| [BPF_JMP | BPF_JGT | BPF_X] = true, |
| [BPF_JMP | BPF_JSET | BPF_K] = true, |
| [BPF_JMP | BPF_JSET | BPF_X] = true, |
| }; |
| |
| if (code_to_probe >= ARRAY_SIZE(codes)) |
| return false; |
| |
| return codes[code_to_probe]; |
| } |
| |
| static bool bpf_check_basics_ok(const struct sock_filter *filter, |
| unsigned int flen) |
| { |
| if (filter == NULL) |
| return false; |
| if (flen == 0 || flen > BPF_MAXINSNS) |
| return false; |
| |
| return true; |
| } |
| |
| /** |
| * bpf_check_classic - verify socket filter code |
| * @filter: filter to verify |
| * @flen: length of filter |
| * |
| * Check the user's filter code. If we let some ugly |
| * filter code slip through kaboom! The filter must contain |
| * no references or jumps that are out of range, no illegal |
| * instructions, and must end with a RET instruction. |
| * |
| * All jumps are forward as they are not signed. |
| * |
| * Returns 0 if the rule set is legal or -EINVAL if not. |
| */ |
| static int bpf_check_classic(const struct sock_filter *filter, |
| unsigned int flen) |
| { |
| bool anc_found; |
| int pc; |
| |
| /* Check the filter code now */ |
| for (pc = 0; pc < flen; pc++) { |
| const struct sock_filter *ftest = &filter[pc]; |
| |
| /* May we actually operate on this code? */ |
| if (!chk_code_allowed(ftest->code)) |
| return -EINVAL; |
| |
| /* Some instructions need special checks */ |
| switch (ftest->code) { |
| case BPF_ALU | BPF_DIV | BPF_K: |
| case BPF_ALU | BPF_MOD | BPF_K: |
| /* Check for division by zero */ |
| if (ftest->k == 0) |
| return -EINVAL; |
| break; |
| case BPF_ALU | BPF_LSH | BPF_K: |
| case BPF_ALU | BPF_RSH | BPF_K: |
| if (ftest->k >= 32) |
| return -EINVAL; |
| break; |
| case BPF_LD | BPF_MEM: |
| case BPF_LDX | BPF_MEM: |
| case BPF_ST: |
| case BPF_STX: |
| /* Check for invalid memory addresses */ |
| if (ftest->k >= BPF_MEMWORDS) |
| return -EINVAL; |
| break; |
| case BPF_JMP | BPF_JA: |
| /* Note, the large ftest->k might cause loops. |
| * Compare this with conditional jumps below, |
| * where offsets are limited. --ANK (981016) |
| */ |
| if (ftest->k >= (unsigned int)(flen - pc - 1)) |
| return -EINVAL; |
| break; |
| case BPF_JMP | BPF_JEQ | BPF_K: |
| case BPF_JMP | BPF_JEQ | BPF_X: |
| case BPF_JMP | BPF_JGE | BPF_K: |
| case BPF_JMP | BPF_JGE | BPF_X: |
| case BPF_JMP | BPF_JGT | BPF_K: |
| case BPF_JMP | BPF_JGT | BPF_X: |
| case BPF_JMP | BPF_JSET | BPF_K: |
| case BPF_JMP | BPF_JSET | BPF_X: |
| /* Both conditionals must be safe */ |
| if (pc + ftest->jt + 1 >= flen || |
| pc + ftest->jf + 1 >= flen) |
| return -EINVAL; |
| break; |
| case BPF_LD | BPF_W | BPF_ABS: |
| case BPF_LD | BPF_H | BPF_ABS: |
| case BPF_LD | BPF_B | BPF_ABS: |
| anc_found = false; |
| if (bpf_anc_helper(ftest) & BPF_ANC) |
| anc_found = true; |
| /* Ancillary operation unknown or unsupported */ |
| if (anc_found == false && ftest->k >= SKF_AD_OFF) |
| return -EINVAL; |
| } |
| } |
| |
| /* Last instruction must be a RET code */ |
| switch (filter[flen - 1].code) { |
| case BPF_RET | BPF_K: |
| case BPF_RET | BPF_A: |
| return check_load_and_stores(filter, flen); |
| } |
| |
| return -EINVAL; |
| } |
| |
| static int bpf_prog_store_orig_filter(struct bpf_prog *fp, |
| const struct sock_fprog *fprog) |
| { |
| unsigned int fsize = bpf_classic_proglen(fprog); |
| struct sock_fprog_kern *fkprog; |
| |
| fp->orig_prog = kmalloc(sizeof(*fkprog), GFP_KERNEL); |
| if (!fp->orig_prog) |
| return -ENOMEM; |
| |
| fkprog = fp->orig_prog; |
| fkprog->len = fprog->len; |
| |
| fkprog->filter = kmemdup(fp->insns, fsize, |
| GFP_KERNEL | __GFP_NOWARN); |
| if (!fkprog->filter) { |
| kfree(fp->orig_prog); |
| return -ENOMEM; |
| } |
| |
| return 0; |
| } |
| |
| static void bpf_release_orig_filter(struct bpf_prog *fp) |
| { |
| struct sock_fprog_kern *fprog = fp->orig_prog; |
| |
| if (fprog) { |
| kfree(fprog->filter); |
| kfree(fprog); |
| } |
| } |
| |
| static void __bpf_prog_release(struct bpf_prog *prog) |
| { |
| if (prog->type == BPF_PROG_TYPE_SOCKET_FILTER) { |
| bpf_prog_put(prog); |
| } else { |
| bpf_release_orig_filter(prog); |
| bpf_prog_free(prog); |
| } |
| } |
| |
| static void __sk_filter_release(struct sk_filter *fp) |
| { |
| __bpf_prog_release(fp->prog); |
| kfree(fp); |
| } |
| |
| /** |
| * sk_filter_release_rcu - Release a socket filter by rcu_head |
| * @rcu: rcu_head that contains the sk_filter to free |
| */ |
| static void sk_filter_release_rcu(struct rcu_head *rcu) |
| { |
| struct sk_filter *fp = container_of(rcu, struct sk_filter, rcu); |
| |
| __sk_filter_release(fp); |
| } |
| |
| /** |
| * sk_filter_release - release a socket filter |
| * @fp: filter to remove |
| * |
| * Remove a filter from a socket and release its resources. |
| */ |
| static void sk_filter_release(struct sk_filter *fp) |
| { |
| if (atomic_dec_and_test(&fp->refcnt)) |
| call_rcu(&fp->rcu, sk_filter_release_rcu); |
| } |
| |
| void sk_filter_uncharge(struct sock *sk, struct sk_filter *fp) |
| { |
| u32 filter_size = bpf_prog_size(fp->prog->len); |
| |
| atomic_sub(filter_size, &sk->sk_omem_alloc); |
| sk_filter_release(fp); |
| } |
| |
| /* try to charge the socket memory if there is space available |
| * return true on success |
| */ |
| bool sk_filter_charge(struct sock *sk, struct sk_filter *fp) |
| { |
| u32 filter_size = bpf_prog_size(fp->prog->len); |
| |
| /* same check as in sock_kmalloc() */ |
| if (filter_size <= sysctl_optmem_max && |
| atomic_read(&sk->sk_omem_alloc) + filter_size < sysctl_optmem_max) { |
| atomic_inc(&fp->refcnt); |
| atomic_add(filter_size, &sk->sk_omem_alloc); |
| return true; |
| } |
| return false; |
| } |
| |
| static struct bpf_prog *bpf_migrate_filter(struct bpf_prog *fp) |
| { |
| struct sock_filter *old_prog; |
| struct bpf_prog *old_fp; |
| int err, new_len, old_len = fp->len; |
| |
| /* We are free to overwrite insns et al right here as it |
| * won't be used at this point in time anymore internally |
| * after the migration to the internal BPF instruction |
| * representation. |
| */ |
| BUILD_BUG_ON(sizeof(struct sock_filter) != |
| sizeof(struct bpf_insn)); |
| |
| /* Conversion cannot happen on overlapping memory areas, |
| * so we need to keep the user BPF around until the 2nd |
| * pass. At this time, the user BPF is stored in fp->insns. |
| */ |
| old_prog = kmemdup(fp->insns, old_len * sizeof(struct sock_filter), |
| GFP_KERNEL | __GFP_NOWARN); |
| if (!old_prog) { |
| err = -ENOMEM; |
| goto out_err; |
| } |
| |
| /* 1st pass: calculate the new program length. */ |
| err = bpf_convert_filter(old_prog, old_len, NULL, &new_len); |
| if (err) |
| goto out_err_free; |
| |
| /* Expand fp for appending the new filter representation. */ |
| old_fp = fp; |
| fp = bpf_prog_realloc(old_fp, bpf_prog_size(new_len), 0); |
| if (!fp) { |
| /* The old_fp is still around in case we couldn't |
| * allocate new memory, so uncharge on that one. |
| */ |
| fp = old_fp; |
| err = -ENOMEM; |
| goto out_err_free; |
| } |
| |
| fp->len = new_len; |
| |
| /* 2nd pass: remap sock_filter insns into bpf_insn insns. */ |
| err = bpf_convert_filter(old_prog, old_len, fp->insnsi, &new_len); |
| if (err) |
| /* 2nd bpf_convert_filter() can fail only if it fails |
| * to allocate memory, remapping must succeed. Note, |
| * that at this time old_fp has already been released |
| * by krealloc(). |
| */ |
| goto out_err_free; |
| |
| /* We are guaranteed to never error here with cBPF to eBPF |
| * transitions, since there's no issue with type compatibility |
| * checks on program arrays. |
| */ |
| fp = bpf_prog_select_runtime(fp, &err); |
| |
| kfree(old_prog); |
| return fp; |
| |
| out_err_free: |
| kfree(old_prog); |
| out_err: |
| __bpf_prog_release(fp); |
| return ERR_PTR(err); |
| } |
| |
| static struct bpf_prog *bpf_prepare_filter(struct bpf_prog *fp, |
| bpf_aux_classic_check_t trans) |
| { |
| int err; |
| |
| fp->bpf_func = NULL; |
| fp->jited = 0; |
| |
| err = bpf_check_classic(fp->insns, fp->len); |
| if (err) { |
| __bpf_prog_release(fp); |
| return ERR_PTR(err); |
| } |
| |
| /* There might be additional checks and transformations |
| * needed on classic filters, f.e. in case of seccomp. |
| */ |
| if (trans) { |
| err = trans(fp->insns, fp->len); |
| if (err) { |
| __bpf_prog_release(fp); |
| return ERR_PTR(err); |
| } |
| } |
| |
| /* Probe if we can JIT compile the filter and if so, do |
| * the compilation of the filter. |
| */ |
| bpf_jit_compile(fp); |
| |
| /* JIT compiler couldn't process this filter, so do the |
| * internal BPF translation for the optimized interpreter. |
| */ |
| if (!fp->jited) |
| fp = bpf_migrate_filter(fp); |
| |
| return fp; |
| } |
| |
| /** |
| * bpf_prog_create - create an unattached filter |
| * @pfp: the unattached filter that is created |
| * @fprog: the filter program |
| * |
| * Create a filter independent of any socket. We first run some |
| * sanity checks on it to make sure it does not explode on us later. |
| * If an error occurs or there is insufficient memory for the filter |
| * a negative errno code is returned. On success the return is zero. |
| */ |
| int bpf_prog_create(struct bpf_prog **pfp, struct sock_fprog_kern *fprog) |
| { |
| unsigned int fsize = bpf_classic_proglen(fprog); |
| struct bpf_prog *fp; |
| |
| /* Make sure new filter is there and in the right amounts. */ |
| if (!bpf_check_basics_ok(fprog->filter, fprog->len)) |
| return -EINVAL; |
| |
| fp = bpf_prog_alloc(bpf_prog_size(fprog->len), 0); |
| if (!fp) |
| return -ENOMEM; |
| |
| memcpy(fp->insns, fprog->filter, fsize); |
| |
| fp->len = fprog->len; |
| /* Since unattached filters are not copied back to user |
| * space through sk_get_filter(), we do not need to hold |
| * a copy here, and can spare us the work. |
| */ |
| fp->orig_prog = NULL; |
| |
| /* bpf_prepare_filter() already takes care of freeing |
| * memory in case something goes wrong. |
| */ |
| fp = bpf_prepare_filter(fp, NULL); |
| if (IS_ERR(fp)) |
| return PTR_ERR(fp); |
| |
| *pfp = fp; |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(bpf_prog_create); |
| |
| /** |
| * bpf_prog_create_from_user - create an unattached filter from user buffer |
| * @pfp: the unattached filter that is created |
| * @fprog: the filter program |
| * @trans: post-classic verifier transformation handler |
| * @save_orig: save classic BPF program |
| * |
| * This function effectively does the same as bpf_prog_create(), only |
| * that it builds up its insns buffer from user space provided buffer. |
| * It also allows for passing a bpf_aux_classic_check_t handler. |
| */ |
| int bpf_prog_create_from_user(struct bpf_prog **pfp, struct sock_fprog *fprog, |
| bpf_aux_classic_check_t trans, bool save_orig) |
| { |
| unsigned int fsize = bpf_classic_proglen(fprog); |
| struct bpf_prog *fp; |
| int err; |
| |
| /* Make sure new filter is there and in the right amounts. */ |
| if (!bpf_check_basics_ok(fprog->filter, fprog->len)) |
| return -EINVAL; |
| |
| fp = bpf_prog_alloc(bpf_prog_size(fprog->len), 0); |
| if (!fp) |
| return -ENOMEM; |
| |
| if (copy_from_user(fp->insns, fprog->filter, fsize)) { |
| __bpf_prog_free(fp); |
| return -EFAULT; |
| } |
| |
| fp->len = fprog->len; |
| fp->orig_prog = NULL; |
| |
| if (save_orig) { |
| err = bpf_prog_store_orig_filter(fp, fprog); |
| if (err) { |
| __bpf_prog_free(fp); |
| return -ENOMEM; |
| } |
| } |
| |
| /* bpf_prepare_filter() already takes care of freeing |
| * memory in case something goes wrong. |
| */ |
| fp = bpf_prepare_filter(fp, trans); |
| if (IS_ERR(fp)) |
| return PTR_ERR(fp); |
| |
| *pfp = fp; |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(bpf_prog_create_from_user); |
| |
| void bpf_prog_destroy(struct bpf_prog *fp) |
| { |
| __bpf_prog_release(fp); |
| } |
| EXPORT_SYMBOL_GPL(bpf_prog_destroy); |
| |
| static int __sk_attach_prog(struct bpf_prog *prog, struct sock *sk) |
| { |
| struct sk_filter *fp, *old_fp; |
| |
| fp = kmalloc(sizeof(*fp), GFP_KERNEL); |
| if (!fp) |
| return -ENOMEM; |
| |
| fp->prog = prog; |
| atomic_set(&fp->refcnt, 0); |
| |
| if (!sk_filter_charge(sk, fp)) { |
| kfree(fp); |
| return -ENOMEM; |
| } |
| |
| old_fp = rcu_dereference_protected(sk->sk_filter, |
| lockdep_sock_is_held(sk)); |
| rcu_assign_pointer(sk->sk_filter, fp); |
| |
| if (old_fp) |
| sk_filter_uncharge(sk, old_fp); |
| |
| return 0; |
| } |
| |
| static int __reuseport_attach_prog(struct bpf_prog *prog, struct sock *sk) |
| { |
| struct bpf_prog *old_prog; |
| int err; |
| |
| if (bpf_prog_size(prog->len) > sysctl_optmem_max) |
| return -ENOMEM; |
| |
| if (sk_unhashed(sk) && sk->sk_reuseport) { |
| err = reuseport_alloc(sk); |
| if (err) |
| return err; |
| } else if (!rcu_access_pointer(sk->sk_reuseport_cb)) { |
| /* The socket wasn't bound with SO_REUSEPORT */ |
| return -EINVAL; |
| } |
| |
| old_prog = reuseport_attach_prog(sk, prog); |
| if (old_prog) |
| bpf_prog_destroy(old_prog); |
| |
| return 0; |
| } |
| |
| static |
| struct bpf_prog *__get_filter(struct sock_fprog *fprog, struct sock *sk) |
| { |
| unsigned int fsize = bpf_classic_proglen(fprog); |
| struct bpf_prog *prog; |
| int err; |
| |
| if (sock_flag(sk, SOCK_FILTER_LOCKED)) |
| return ERR_PTR(-EPERM); |
| |
| /* Make sure new filter is there and in the right amounts. */ |
| if (!bpf_check_basics_ok(fprog->filter, fprog->len)) |
| return ERR_PTR(-EINVAL); |
| |
| prog = bpf_prog_alloc(bpf_prog_size(fprog->len), 0); |
| if (!prog) |
| return ERR_PTR(-ENOMEM); |
| |
| if (copy_from_user(prog->insns, fprog->filter, fsize)) { |
| __bpf_prog_free(prog); |
| return ERR_PTR(-EFAULT); |
| } |
| |
| prog->len = fprog->len; |
| |
| err = bpf_prog_store_orig_filter(prog, fprog); |
| if (err) { |
| __bpf_prog_free(prog); |
| return ERR_PTR(-ENOMEM); |
| } |
| |
| /* bpf_prepare_filter() already takes care of freeing |
| * memory in case something goes wrong. |
| */ |
| return bpf_prepare_filter(prog, NULL); |
| } |
| |
| /** |
| * sk_attach_filter - attach a socket filter |
| * @fprog: the filter program |
| * @sk: the socket to use |
| * |
| * Attach the user's filter code. We first run some sanity checks on |
| * it to make sure it does not explode on us later. If an error |
| * occurs or there is insufficient memory for the filter a negative |
| * errno code is returned. On success the return is zero. |
| */ |
| int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk) |
| { |
| struct bpf_prog *prog = __get_filter(fprog, sk); |
| int err; |
| |
| if (IS_ERR(prog)) |
| return PTR_ERR(prog); |
| |
| err = __sk_attach_prog(prog, sk); |
| if (err < 0) { |
| __bpf_prog_release(prog); |
| return err; |
| } |
| |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(sk_attach_filter); |
| |
| int sk_reuseport_attach_filter(struct sock_fprog *fprog, struct sock *sk) |
| { |
| struct bpf_prog *prog = __get_filter(fprog, sk); |
| int err; |
| |
| if (IS_ERR(prog)) |
| return PTR_ERR(prog); |
| |
| err = __reuseport_attach_prog(prog, sk); |
| if (err < 0) { |
| __bpf_prog_release(prog); |
| return err; |
| } |
| |
| return 0; |
| } |
| |
| static struct bpf_prog *__get_bpf(u32 ufd, struct sock *sk) |
| { |
| if (sock_flag(sk, SOCK_FILTER_LOCKED)) |
| return ERR_PTR(-EPERM); |
| |
| return bpf_prog_get_type(ufd, BPF_PROG_TYPE_SOCKET_FILTER); |
| } |
| |
| int sk_attach_bpf(u32 ufd, struct sock *sk) |
| { |
| struct bpf_prog *prog = __get_bpf(ufd, sk); |
| int err; |
| |
| if (IS_ERR(prog)) |
| return PTR_ERR(prog); |
| |
| err = __sk_attach_prog(prog, sk); |
| if (err < 0) { |
| bpf_prog_put(prog); |
| return err; |
| } |
| |
| return 0; |
| } |
| |
| int sk_reuseport_attach_bpf(u32 ufd, struct sock *sk) |
| { |
| struct bpf_prog *prog = __get_bpf(ufd, sk); |
| int err; |
| |
| if (IS_ERR(prog)) |
| return PTR_ERR(prog); |
| |
| err = __reuseport_attach_prog(prog, sk); |
| if (err < 0) { |
| bpf_prog_put(prog); |
| return err; |
| } |
| |
| return 0; |
| } |
| |
| struct bpf_scratchpad { |
| union { |
| __be32 diff[MAX_BPF_STACK / sizeof(__be32)]; |
| u8 buff[MAX_BPF_STACK]; |
| }; |
| }; |
| |
| static DEFINE_PER_CPU(struct bpf_scratchpad, bpf_sp); |
| |
| static inline int bpf_try_make_writable(struct sk_buff *skb, |
| unsigned int write_len) |
| { |
| int err; |
| |
| if (!skb_cloned(skb)) |
| return 0; |
| if (skb_clone_writable(skb, write_len)) |
| return 0; |
| err = pskb_expand_head(skb, 0, 0, GFP_ATOMIC); |
| if (!err) |
| bpf_compute_data_end(skb); |
| return err; |
| } |
| |
| static inline void bpf_push_mac_rcsum(struct sk_buff *skb) |
| { |
| if (skb_at_tc_ingress(skb)) |
| skb_postpush_rcsum(skb, skb_mac_header(skb), skb->mac_len); |
| } |
| |
| static inline void bpf_pull_mac_rcsum(struct sk_buff *skb) |
| { |
| if (skb_at_tc_ingress(skb)) |
| skb_postpull_rcsum(skb, skb_mac_header(skb), skb->mac_len); |
| } |
| |
| static u64 bpf_skb_store_bytes(u64 r1, u64 r2, u64 r3, u64 r4, u64 flags) |
| { |
| struct bpf_scratchpad *sp = this_cpu_ptr(&bpf_sp); |
| struct sk_buff *skb = (struct sk_buff *) (long) r1; |
| int offset = (int) r2; |
| void *from = (void *) (long) r3; |
| unsigned int len = (unsigned int) r4; |
| void *ptr; |
| |
| if (unlikely(flags & ~(BPF_F_RECOMPUTE_CSUM | BPF_F_INVALIDATE_HASH))) |
| return -EINVAL; |
| |
| /* bpf verifier guarantees that: |
| * 'from' pointer points to bpf program stack |
| * 'len' bytes of it were initialized |
| * 'len' > 0 |
| * 'skb' is a valid pointer to 'struct sk_buff' |
| * |
| * so check for invalid 'offset' and too large 'len' |
| */ |
| if (unlikely((u32) offset > 0xffff || len > sizeof(sp->buff))) |
| return -EFAULT; |
| if (unlikely(bpf_try_make_writable(skb, offset + len))) |
| return -EFAULT; |
| |
| ptr = skb_header_pointer(skb, offset, len, sp->buff); |
| if (unlikely(!ptr)) |
| return -EFAULT; |
| |
| if (flags & BPF_F_RECOMPUTE_CSUM) |
| __skb_postpull_rcsum(skb, ptr, len, offset); |
| |
| memcpy(ptr, from, len); |
| |
| if (ptr == sp->buff) |
| /* skb_store_bits cannot return -EFAULT here */ |
| skb_store_bits(skb, offset, ptr, len); |
| |
| if (flags & BPF_F_RECOMPUTE_CSUM) |
| __skb_postpush_rcsum(skb, ptr, len, offset); |
| if (flags & BPF_F_INVALIDATE_HASH) |
| skb_clear_hash(skb); |
| |
| return 0; |
| } |
| |
| static const struct bpf_func_proto bpf_skb_store_bytes_proto = { |
| .func = bpf_skb_store_bytes, |
| .gpl_only = false, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_PTR_TO_CTX, |
| .arg2_type = ARG_ANYTHING, |
| .arg3_type = ARG_PTR_TO_STACK, |
| .arg4_type = ARG_CONST_STACK_SIZE, |
| .arg5_type = ARG_ANYTHING, |
| }; |
| |
| static u64 bpf_skb_load_bytes(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5) |
| { |
| const struct sk_buff *skb = (const struct sk_buff *)(unsigned long) r1; |
| int offset = (int) r2; |
| void *to = (void *)(unsigned long) r3; |
| unsigned int len = (unsigned int) r4; |
| void *ptr; |
| |
| if (unlikely((u32) offset > 0xffff)) |
| goto err_clear; |
| |
| ptr = skb_header_pointer(skb, offset, len, to); |
| if (unlikely(!ptr)) |
| goto err_clear; |
| if (ptr != to) |
| memcpy(to, ptr, len); |
| |
| return 0; |
| err_clear: |
| memset(to, 0, len); |
| return -EFAULT; |
| } |
| |
| static const struct bpf_func_proto bpf_skb_load_bytes_proto = { |
| .func = bpf_skb_load_bytes, |
| .gpl_only = false, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_PTR_TO_CTX, |
| .arg2_type = ARG_ANYTHING, |
| .arg3_type = ARG_PTR_TO_RAW_STACK, |
| .arg4_type = ARG_CONST_STACK_SIZE, |
| }; |
| |
| static u64 bpf_l3_csum_replace(u64 r1, u64 r2, u64 from, u64 to, u64 flags) |
| { |
| struct sk_buff *skb = (struct sk_buff *) (long) r1; |
| int offset = (int) r2; |
| __sum16 sum, *ptr; |
| |
| if (unlikely(flags & ~(BPF_F_HDR_FIELD_MASK))) |
| return -EINVAL; |
| if (unlikely((u32) offset > 0xffff)) |
| return -EFAULT; |
| if (unlikely(bpf_try_make_writable(skb, offset + sizeof(sum)))) |
| return -EFAULT; |
| |
| ptr = skb_header_pointer(skb, offset, sizeof(sum), &sum); |
| if (unlikely(!ptr)) |
| return -EFAULT; |
| |
| switch (flags & BPF_F_HDR_FIELD_MASK) { |
| case 0: |
| if (unlikely(from != 0)) |
| return -EINVAL; |
| |
| csum_replace_by_diff(ptr, to); |
| break; |
| case 2: |
| csum_replace2(ptr, from, to); |
| break; |
| case 4: |
| csum_replace4(ptr, from, to); |
| break; |
| default: |
| return -EINVAL; |
| } |
| |
| if (ptr == &sum) |
| /* skb_store_bits guaranteed to not return -EFAULT here */ |
| skb_store_bits(skb, offset, ptr, sizeof(sum)); |
| |
| return 0; |
| } |
| |
| static const struct bpf_func_proto bpf_l3_csum_replace_proto = { |
| .func = bpf_l3_csum_replace, |
| .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, |
| .arg5_type = ARG_ANYTHING, |
| }; |
| |
| static u64 bpf_l4_csum_replace(u64 r1, u64 r2, u64 from, u64 to, u64 flags) |
| { |
| struct sk_buff *skb = (struct sk_buff *) (long) r1; |
| bool is_pseudo = flags & BPF_F_PSEUDO_HDR; |
| bool is_mmzero = flags & BPF_F_MARK_MANGLED_0; |
| int offset = (int) r2; |
| __sum16 sum, *ptr; |
| |
| if (unlikely(flags & ~(BPF_F_MARK_MANGLED_0 | BPF_F_PSEUDO_HDR | |
| BPF_F_HDR_FIELD_MASK))) |
| return -EINVAL; |
| if (unlikely((u32) offset > 0xffff)) |
| return -EFAULT; |
| if (unlikely(bpf_try_make_writable(skb, offset + sizeof(sum)))) |
| return -EFAULT; |
| |
| ptr = skb_header_pointer(skb, offset, sizeof(sum), &sum); |
| if (unlikely(!ptr)) |
| return -EFAULT; |
| if (is_mmzero && !*ptr) |
| return 0; |
| |
| switch (flags & BPF_F_HDR_FIELD_MASK) { |
| case 0: |
| if (unlikely(from != 0)) |
| return -EINVAL; |
| |
| inet_proto_csum_replace_by_diff(ptr, skb, to, is_pseudo); |
| break; |
| case 2: |
| inet_proto_csum_replace2(ptr, skb, from, to, is_pseudo); |
| break; |
| case 4: |
| inet_proto_csum_replace4(ptr, skb, from, to, is_pseudo); |
| break; |
| default: |
| return -EINVAL; |
| } |
| |
| if (is_mmzero && !*ptr) |
| *ptr = CSUM_MANGLED_0; |
| if (ptr == &sum) |
| /* skb_store_bits guaranteed to not return -EFAULT here */ |
| skb_store_bits(skb, offset, ptr, sizeof(sum)); |
| |
| return 0; |
| } |
| |
| static const struct bpf_func_proto bpf_l4_csum_replace_proto = { |
| .func = bpf_l4_csum_replace, |
| .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, |
| .arg5_type = ARG_ANYTHING, |
| }; |
| |
| static u64 bpf_csum_diff(u64 r1, u64 from_size, u64 r3, u64 to_size, u64 seed) |
| { |
| struct bpf_scratchpad *sp = this_cpu_ptr(&bpf_sp); |
| u64 diff_size = from_size + to_size; |
| __be32 *from = (__be32 *) (long) r1; |
| __be32 *to = (__be32 *) (long) r3; |
| int i, j = 0; |
| |
| /* This is quite flexible, some examples: |
| * |
| * from_size == 0, to_size > 0, seed := csum --> pushing data |
| * from_size > 0, to_size == 0, seed := csum --> pulling data |
| * from_size > 0, to_size > 0, seed := 0 --> diffing data |
| * |
| * Even for diffing, from_size and to_size don't need to be equal. |
| */ |
| if (unlikely(((from_size | to_size) & (sizeof(__be32) - 1)) || |
| diff_size > sizeof(sp->diff))) |
| return -EINVAL; |
| |
| for (i = 0; i < from_size / sizeof(__be32); i++, j++) |
| sp->diff[j] = ~from[i]; |
| for (i = 0; i < to_size / sizeof(__be32); i++, j++) |
| sp->diff[j] = to[i]; |
| |
| return csum_partial(sp->diff, diff_size, seed); |
| } |
| |
| static const struct bpf_func_proto bpf_csum_diff_proto = { |
| .func = bpf_csum_diff, |
| .gpl_only = false, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_PTR_TO_STACK, |
| .arg2_type = ARG_CONST_STACK_SIZE_OR_ZERO, |
| .arg3_type = ARG_PTR_TO_STACK, |
| .arg4_type = ARG_CONST_STACK_SIZE_OR_ZERO, |
| .arg5_type = ARG_ANYTHING, |
| }; |
| |
| static inline int __bpf_rx_skb(struct net_device *dev, struct sk_buff *skb) |
| { |
| return dev_forward_skb(dev, skb); |
| } |
| |
| static inline int __bpf_tx_skb(struct net_device *dev, struct sk_buff *skb) |
| { |
| int ret; |
| |
| if (unlikely(__this_cpu_read(xmit_recursion) > XMIT_RECURSION_LIMIT)) { |
| net_crit_ratelimited("bpf: recursion limit reached on datapath, buggy bpf program?\n"); |
| kfree_skb(skb); |
| return -ENETDOWN; |
| } |
| |
| skb->dev = dev; |
| |
| __this_cpu_inc(xmit_recursion); |
| ret = dev_queue_xmit(skb); |
| __this_cpu_dec(xmit_recursion); |
| |
| return ret; |
| } |
| |
| static u64 bpf_clone_redirect(u64 r1, u64 ifindex, u64 flags, u64 r4, u64 r5) |
| { |
| struct sk_buff *skb = (struct sk_buff *) (long) r1; |
| struct net_device *dev; |
| |
| if (unlikely(flags & ~(BPF_F_INGRESS))) |
| return -EINVAL; |
| |
| dev = dev_get_by_index_rcu(dev_net(skb->dev), ifindex); |
| if (unlikely(!dev)) |
| return -EINVAL; |
| |
| skb = skb_clone(skb, GFP_ATOMIC); |
| if (unlikely(!skb)) |
| return -ENOMEM; |
| |
| bpf_push_mac_rcsum(skb); |
| |
| return flags & BPF_F_INGRESS ? |
| __bpf_rx_skb(dev, skb) : __bpf_tx_skb(dev, skb); |
| } |
| |
| static const struct bpf_func_proto bpf_clone_redirect_proto = { |
| .func = bpf_clone_redirect, |
| .gpl_only = false, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_PTR_TO_CTX, |
| .arg2_type = ARG_ANYTHING, |
| .arg3_type = ARG_ANYTHING, |
| }; |
| |
| struct redirect_info { |
| u32 ifindex; |
| u32 flags; |
| }; |
| |
| static DEFINE_PER_CPU(struct redirect_info, redirect_info); |
| |
| static u64 bpf_redirect(u64 ifindex, u64 flags, u64 r3, u64 r4, u64 r5) |
| { |
| struct redirect_info *ri = this_cpu_ptr(&redirect_info); |
| |
| if (unlikely(flags & ~(BPF_F_INGRESS))) |
| return TC_ACT_SHOT; |
| |
| ri->ifindex = ifindex; |
| ri->flags = flags; |
| |
| return TC_ACT_REDIRECT; |
| } |
| |
| int skb_do_redirect(struct sk_buff *skb) |
| { |
| struct redirect_info *ri = this_cpu_ptr(&redirect_info); |
| struct net_device *dev; |
| |
| dev = dev_get_by_index_rcu(dev_net(skb->dev), ri->ifindex); |
| ri->ifindex = 0; |
| if (unlikely(!dev)) { |
| kfree_skb(skb); |
| return -EINVAL; |
| } |
| |
| bpf_push_mac_rcsum(skb); |
| |
| return ri->flags & BPF_F_INGRESS ? |
| __bpf_rx_skb(dev, skb) : __bpf_tx_skb(dev, skb); |
| } |
| |
| static const struct bpf_func_proto bpf_redirect_proto = { |
| .func = bpf_redirect, |
| .gpl_only = false, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_ANYTHING, |
| .arg2_type = ARG_ANYTHING, |
| }; |
| |
| static u64 bpf_get_cgroup_classid(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5) |
| { |
| return task_get_classid((struct sk_buff *) (unsigned long) r1); |
| } |
| |
| static const struct bpf_func_proto bpf_get_cgroup_classid_proto = { |
| .func = bpf_get_cgroup_classid, |
| .gpl_only = false, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_PTR_TO_CTX, |
| }; |
| |
| static u64 bpf_get_route_realm(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5) |
| { |
| return dst_tclassid((struct sk_buff *) (unsigned long) r1); |
| } |
| |
| static const struct bpf_func_proto bpf_get_route_realm_proto = { |
| .func = bpf_get_route_realm, |
| .gpl_only = false, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_PTR_TO_CTX, |
| }; |
| |
| static u64 bpf_get_hash_recalc(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5) |
| { |
| /* If skb_clear_hash() was called due to mangling, we can |
| * trigger SW recalculation here. Later access to hash |
| * can then use the inline skb->hash via context directly |
| * instead of calling this helper again. |
| */ |
| return skb_get_hash((struct sk_buff *) (unsigned long) r1); |
| } |
| |
| static const struct bpf_func_proto bpf_get_hash_recalc_proto = { |
| .func = bpf_get_hash_recalc, |
| .gpl_only = false, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_PTR_TO_CTX, |
| }; |
| |
| static u64 bpf_skb_vlan_push(u64 r1, u64 r2, u64 vlan_tci, u64 r4, u64 r5) |
| { |
| struct sk_buff *skb = (struct sk_buff *) (long) r1; |
| __be16 vlan_proto = (__force __be16) r2; |
| int ret; |
| |
| if (unlikely(vlan_proto != htons(ETH_P_8021Q) && |
| vlan_proto != htons(ETH_P_8021AD))) |
| vlan_proto = htons(ETH_P_8021Q); |
| |
| bpf_push_mac_rcsum(skb); |
| ret = skb_vlan_push(skb, vlan_proto, vlan_tci); |
| bpf_pull_mac_rcsum(skb); |
| |
| bpf_compute_data_end(skb); |
| return ret; |
| } |
| |
| const struct bpf_func_proto bpf_skb_vlan_push_proto = { |
| .func = bpf_skb_vlan_push, |
| .gpl_only = false, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_PTR_TO_CTX, |
| .arg2_type = ARG_ANYTHING, |
| .arg3_type = ARG_ANYTHING, |
| }; |
| EXPORT_SYMBOL_GPL(bpf_skb_vlan_push_proto); |
| |
| static u64 bpf_skb_vlan_pop(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5) |
| { |
| struct sk_buff *skb = (struct sk_buff *) (long) r1; |
| int ret; |
| |
| bpf_push_mac_rcsum(skb); |
| ret = skb_vlan_pop(skb); |
| bpf_pull_mac_rcsum(skb); |
| |
| bpf_compute_data_end(skb); |
| return ret; |
| } |
| |
| const struct bpf_func_proto bpf_skb_vlan_pop_proto = { |
| .func = bpf_skb_vlan_pop, |
| .gpl_only = false, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_PTR_TO_CTX, |
| }; |
| EXPORT_SYMBOL_GPL(bpf_skb_vlan_pop_proto); |
| |
| static int bpf_skb_generic_push(struct sk_buff *skb, u32 off, u32 len) |
| { |
| /* Caller already did skb_cow() with len as headroom, |
| * so no need to do it here. |
| */ |
| skb_push(skb, len); |
| memmove(skb->data, skb->data + len, off); |
| memset(skb->data + off, 0, len); |
| |
| /* No skb_postpush_rcsum(skb, skb->data + off, len) |
| * needed here as it does not change the skb->csum |
| * result for checksum complete when summing over |
| * zeroed blocks. |
| */ |
| return 0; |
| } |
| |
| static int bpf_skb_generic_pop(struct sk_buff *skb, u32 off, u32 len) |
| { |
| /* skb_ensure_writable() is not needed here, as we're |
| * already working on an uncloned skb. |
| */ |
| if (unlikely(!pskb_may_pull(skb, off + len))) |
| return -ENOMEM; |
| |
| skb_postpull_rcsum(skb, skb->data + off, len); |
| memmove(skb->data + len, skb->data, off); |
| __skb_pull(skb, len); |
| |
| return 0; |
| } |
| |
| static int bpf_skb_net_hdr_push(struct sk_buff *skb, u32 off, u32 len) |
| { |
| bool trans_same = skb->transport_header == skb->network_header; |
| int ret; |
| |
| /* There's no need for __skb_push()/__skb_pull() pair to |
| * get to the start of the mac header as we're guaranteed |
| * to always start from here under eBPF. |
| */ |
| ret = bpf_skb_generic_push(skb, off, len); |
| if (likely(!ret)) { |
| skb->mac_header -= len; |
| skb->network_header -= len; |
| if (trans_same) |
| skb->transport_header = skb->network_header; |
| } |
| |
| return ret; |
| } |
| |
| static int bpf_skb_net_hdr_pop(struct sk_buff *skb, u32 off, u32 len) |
| { |
| bool trans_same = skb->transport_header == skb->network_header; |
| int ret; |
| |
| /* Same here, __skb_push()/__skb_pull() pair not needed. */ |
| ret = bpf_skb_generic_pop(skb, off, len); |
| if (likely(!ret)) { |
| skb->mac_header += len; |
| skb->network_header += len; |
| if (trans_same) |
| skb->transport_header = skb->network_header; |
| } |
| |
| return ret; |
| } |
| |
| static int bpf_skb_proto_4_to_6(struct sk_buff *skb) |
| { |
| const u32 len_diff = sizeof(struct ipv6hdr) - sizeof(struct iphdr); |
| u32 off = skb->network_header - skb->mac_header; |
| int ret; |
| |
| ret = skb_cow(skb, len_diff); |
| if (unlikely(ret < 0)) |
| return ret; |
| |
| ret = bpf_skb_net_hdr_push(skb, off, len_diff); |
| if (unlikely(ret < 0)) |
| return ret; |
| |
| if (skb_is_gso(skb)) { |
| /* SKB_GSO_UDP stays as is. SKB_GSO_TCPV4 needs to |
| * be changed into SKB_GSO_TCPV6. |
| */ |
| if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4) { |
| skb_shinfo(skb)->gso_type &= ~SKB_GSO_TCPV4; |
| skb_shinfo(skb)->gso_type |= SKB_GSO_TCPV6; |
| } |
| |
| /* Due to IPv6 header, MSS needs to be downgraded. */ |
| skb_shinfo(skb)->gso_size -= len_diff; |
| /* Header must be checked, and gso_segs recomputed. */ |
| skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY; |
| skb_shinfo(skb)->gso_segs = 0; |
| } |
| |
| skb->protocol = htons(ETH_P_IPV6); |
| skb_clear_hash(skb); |
| |
| return 0; |
| } |
| |
| static int bpf_skb_proto_6_to_4(struct sk_buff *skb) |
| { |
| const u32 len_diff = sizeof(struct ipv6hdr) - sizeof(struct iphdr); |
| u32 off = skb->network_header - skb->mac_header; |
| int ret; |
| |
| ret = skb_unclone(skb, GFP_ATOMIC); |
| if (unlikely(ret < 0)) |
| return ret; |
| |
| ret = bpf_skb_net_hdr_pop(skb, off, len_diff); |
| if (unlikely(ret < 0)) |
| return ret; |
| |
| if (skb_is_gso(skb)) { |
| /* SKB_GSO_UDP stays as is. SKB_GSO_TCPV6 needs to |
| * be changed into SKB_GSO_TCPV4. |
| */ |
| if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6) { |
| skb_shinfo(skb)->gso_type &= ~SKB_GSO_TCPV6; |
| skb_shinfo(skb)->gso_type |= SKB_GSO_TCPV4; |
| } |
| |
| /* Due to IPv4 header, MSS can be upgraded. */ |
| skb_shinfo(skb)->gso_size += len_diff; |
| /* Header must be checked, and gso_segs recomputed. */ |
| skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY; |
| skb_shinfo(skb)->gso_segs = 0; |
| } |
| |
| skb->protocol = htons(ETH_P_IP); |
| skb_clear_hash(skb); |
| |
| return 0; |
| } |
| |
| static int bpf_skb_proto_xlat(struct sk_buff *skb, __be16 to_proto) |
| { |
| __be16 from_proto = skb->protocol; |
| |
| if (from_proto == htons(ETH_P_IP) && |
| to_proto == htons(ETH_P_IPV6)) |
| return bpf_skb_proto_4_to_6(skb); |
| |
| if (from_proto == htons(ETH_P_IPV6) && |
| to_proto == htons(ETH_P_IP)) |
| return bpf_skb_proto_6_to_4(skb); |
| |
| return -ENOTSUPP; |
| } |
| |
| static u64 bpf_skb_change_proto(u64 r1, u64 r2, u64 flags, u64 r4, u64 r5) |
| { |
| struct sk_buff *skb = (struct sk_buff *) (long) r1; |
| __be16 proto = (__force __be16) r2; |
| int ret; |
| |
| if (unlikely(flags)) |
| return -EINVAL; |
| |
| /* General idea is that this helper does the basic groundwork |
| * needed for changing the protocol, and eBPF program fills the |
| * rest through bpf_skb_store_bytes(), bpf_lX_csum_replace() |
| * and other helpers, rather than passing a raw buffer here. |
| * |
| * The rationale is to keep this minimal and without a need to |
| * deal with raw packet data. F.e. even if we would pass buffers |
| * here, the program still needs to call the bpf_lX_csum_replace() |
| * helpers anyway. Plus, this way we keep also separation of |
| * concerns, since f.e. bpf_skb_store_bytes() should only take |
| * care of stores. |
| * |
| * Currently, additional options and extension header space are |
| * not supported, but flags register is reserved so we can adapt |
| * that. For offloads, we mark packet as dodgy, so that headers |
| * need to be verified first. |
| */ |
| ret = bpf_skb_proto_xlat(skb, proto); |
| bpf_compute_data_end(skb); |
| return ret; |
| } |
| |
| static const struct bpf_func_proto bpf_skb_change_proto_proto = { |
| .func = bpf_skb_change_proto, |
| .gpl_only = false, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_PTR_TO_CTX, |
| .arg2_type = ARG_ANYTHING, |
| .arg3_type = ARG_ANYTHING, |
| }; |
| |
| static u64 bpf_skb_change_type(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5) |
| { |
| struct sk_buff *skb = (struct sk_buff *) (long) r1; |
| u32 pkt_type = r2; |
| |
| /* We only allow a restricted subset to be changed for now. */ |
| if (unlikely(skb->pkt_type > PACKET_OTHERHOST || |
| pkt_type > PACKET_OTHERHOST)) |
| return -EINVAL; |
| |
| skb->pkt_type = pkt_type; |
| return 0; |
| } |
| |
| static const struct bpf_func_proto bpf_skb_change_type_proto = { |
| .func = bpf_skb_change_type, |
| .gpl_only = false, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_PTR_TO_CTX, |
| .arg2_type = ARG_ANYTHING, |
| }; |
| |
| bool bpf_helper_changes_skb_data(void *func) |
| { |
| if (func == bpf_skb_vlan_push) |
| return true; |
| if (func == bpf_skb_vlan_pop) |
| return true; |
| if (func == bpf_skb_store_bytes) |
| return true; |
| if (func == bpf_skb_change_proto) |
| return true; |
| if (func == bpf_l3_csum_replace) |
| return true; |
| if (func == bpf_l4_csum_replace) |
| return true; |
| |
| return false; |
| } |
| |
| static unsigned long bpf_skb_copy(void *dst_buff, const void *skb, |
| unsigned long off, unsigned long len) |
| { |
| void *ptr = skb_header_pointer(skb, off, len, dst_buff); |
| |
| if (unlikely(!ptr)) |
| return len; |
| if (ptr != dst_buff) |
| memcpy(dst_buff, ptr, len); |
| |
| return 0; |
| } |
| |
| static u64 bpf_skb_event_output(u64 r1, u64 r2, u64 flags, u64 r4, |
| u64 meta_size) |
| { |
| struct sk_buff *skb = (struct sk_buff *)(long) r1; |
| struct bpf_map *map = (struct bpf_map *)(long) r2; |
| u64 skb_size = (flags & BPF_F_CTXLEN_MASK) >> 32; |
| void *meta = (void *)(long) r4; |
| |
| if (unlikely(flags & ~(BPF_F_CTXLEN_MASK | BPF_F_INDEX_MASK))) |
| return -EINVAL; |
| if (unlikely(skb_size > skb->len)) |
| return -EFAULT; |
| |
| return bpf_event_output(map, flags, meta, meta_size, skb, skb_size, |
| bpf_skb_copy); |
| } |
| |
| static const struct bpf_func_proto bpf_skb_event_output_proto = { |
| .func = bpf_skb_event_output, |
| .gpl_only = true, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_PTR_TO_CTX, |
| .arg2_type = ARG_CONST_MAP_PTR, |
| .arg3_type = ARG_ANYTHING, |
| .arg4_type = ARG_PTR_TO_STACK, |
| .arg5_type = ARG_CONST_STACK_SIZE, |
| }; |
| |
| static unsigned short bpf_tunnel_key_af(u64 flags) |
| { |
| return flags & BPF_F_TUNINFO_IPV6 ? AF_INET6 : AF_INET; |
| } |
| |
| static u64 bpf_skb_get_tunnel_key(u64 r1, u64 r2, u64 size, u64 flags, u64 r5) |
| { |
| struct sk_buff *skb = (struct sk_buff *) (long) r1; |
| struct bpf_tunnel_key *to = (struct bpf_tunnel_key *) (long) r2; |
| const struct ip_tunnel_info *info = skb_tunnel_info(skb); |
| u8 compat[sizeof(struct bpf_tunnel_key)]; |
| void *to_orig = to; |
| int err; |
| |
| if (unlikely(!info || (flags & ~(BPF_F_TUNINFO_IPV6)))) { |
| err = -EINVAL; |
| goto err_clear; |
| } |
| if (ip_tunnel_info_af(info) != bpf_tunnel_key_af(flags)) { |
| err = -EPROTO; |
| goto err_clear; |
| } |
| if (unlikely(size != sizeof(struct bpf_tunnel_key))) { |
| err = -EINVAL; |
| switch (size) { |
| case offsetof(struct bpf_tunnel_key, tunnel_label): |
| case offsetof(struct bpf_tunnel_key, tunnel_ext): |
| goto set_compat; |
| case offsetof(struct bpf_tunnel_key, remote_ipv6[1]): |
| /* Fixup deprecated structure layouts here, so we have |
| * a common path later on. |
| */ |
| if (ip_tunnel_info_af(info) != AF_INET) |
| goto err_clear; |
| set_compat: |
| to = (struct bpf_tunnel_key *)compat; |
| break; |
| default: |
| goto err_clear; |
| } |
| } |
| |
| to->tunnel_id = be64_to_cpu(info->key.tun_id); |
| to->tunnel_tos = info->key.tos; |
| to->tunnel_ttl = info->key.ttl; |
| |
| if (flags & BPF_F_TUNINFO_IPV6) { |
| memcpy(to->remote_ipv6, &info->key.u.ipv6.src, |
| sizeof(to->remote_ipv6)); |
| to->tunnel_label = be32_to_cpu(info->key.label); |
| } else { |
| to->remote_ipv4 = be32_to_cpu(info->key.u.ipv4.src); |
| } |
| |
| if (unlikely(size != sizeof(struct bpf_tunnel_key))) |
| memcpy(to_orig, to, size); |
| |
| return 0; |
| err_clear: |
| memset(to_orig, 0, size); |
| return err; |
| } |
| |
| static const struct bpf_func_proto bpf_skb_get_tunnel_key_proto = { |
| .func = bpf_skb_get_tunnel_key, |
| .gpl_only = false, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_PTR_TO_CTX, |
| .arg2_type = ARG_PTR_TO_RAW_STACK, |
| .arg3_type = ARG_CONST_STACK_SIZE, |
| .arg4_type = ARG_ANYTHING, |
| }; |
| |
| static u64 bpf_skb_get_tunnel_opt(u64 r1, u64 r2, u64 size, u64 r4, u64 r5) |
| { |
| struct sk_buff *skb = (struct sk_buff *) (long) r1; |
| u8 *to = (u8 *) (long) r2; |
| const struct ip_tunnel_info *info = skb_tunnel_info(skb); |
| int err; |
| |
| if (unlikely(!info || |
| !(info->key.tun_flags & TUNNEL_OPTIONS_PRESENT))) { |
| err = -ENOENT; |
| goto err_clear; |
| } |
| if (unlikely(size < info->options_len)) { |
| err = -ENOMEM; |
| goto err_clear; |
| } |
| |
| ip_tunnel_info_opts_get(to, info); |
| if (size > info->options_len) |
| memset(to + info->options_len, 0, size - info->options_len); |
| |
| return info->options_len; |
| err_clear: |
| memset(to, 0, size); |
| return err; |
| } |
| |
| static const struct bpf_func_proto bpf_skb_get_tunnel_opt_proto = { |
| .func = bpf_skb_get_tunnel_opt, |
| .gpl_only = false, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_PTR_TO_CTX, |
| .arg2_type = ARG_PTR_TO_RAW_STACK, |
| .arg3_type = ARG_CONST_STACK_SIZE, |
| }; |
| |
| static struct metadata_dst __percpu *md_dst; |
| |
| static u64 bpf_skb_set_tunnel_key(u64 r1, u64 r2, u64 size, u64 flags, u64 r5) |
| { |
| struct sk_buff *skb = (struct sk_buff *) (long) r1; |
| struct bpf_tunnel_key *from = (struct bpf_tunnel_key *) (long) r2; |
| struct metadata_dst *md = this_cpu_ptr(md_dst); |
| u8 compat[sizeof(struct bpf_tunnel_key)]; |
| struct ip_tunnel_info *info; |
| |
| if (unlikely(flags & ~(BPF_F_TUNINFO_IPV6 | BPF_F_ZERO_CSUM_TX | |
| BPF_F_DONT_FRAGMENT))) |
| return -EINVAL; |
| if (unlikely(size != sizeof(struct bpf_tunnel_key))) { |
| switch (size) { |
| case offsetof(struct bpf_tunnel_key, tunnel_label): |
| case offsetof(struct bpf_tunnel_key, tunnel_ext): |
| case offsetof(struct bpf_tunnel_key, remote_ipv6[1]): |
| /* Fixup deprecated structure layouts here, so we have |
| * a common path later on. |
| */ |
| memcpy(compat, from, size); |
| memset(compat + size, 0, sizeof(compat) - size); |
| from = (struct bpf_tunnel_key *)compat; |
| break; |
| default: |
| return -EINVAL; |
| } |
| } |
| if (unlikely((!(flags & BPF_F_TUNINFO_IPV6) && from->tunnel_label) || |
| from->tunnel_ext)) |
| return -EINVAL; |
| |
| skb_dst_drop(skb); |
| dst_hold((struct dst_entry *) md); |
| skb_dst_set(skb, (struct dst_entry *) md); |
| |
| info = &md->u.tun_info; |
| info->mode = IP_TUNNEL_INFO_TX; |
| |
| info->key.tun_flags = TUNNEL_KEY | TUNNEL_CSUM | TUNNEL_NOCACHE; |
| if (flags & BPF_F_DONT_FRAGMENT) |
| info->key.tun_flags |= TUNNEL_DONT_FRAGMENT; |
| |
| info->key.tun_id = cpu_to_be64(from->tunnel_id); |
| info->key.tos = from->tunnel_tos; |
| info->key.ttl = from->tunnel_ttl; |
| |
| if (flags & BPF_F_TUNINFO_IPV6) { |
| info->mode |= IP_TUNNEL_INFO_IPV6; |
| memcpy(&info->key.u.ipv6.dst, from->remote_ipv6, |
| sizeof(from->remote_ipv6)); |
| info->key.label = cpu_to_be32(from->tunnel_label) & |
| IPV6_FLOWLABEL_MASK; |
| } else { |
| info->key.u.ipv4.dst = cpu_to_be32(from->remote_ipv4); |
| if (flags & BPF_F_ZERO_CSUM_TX) |
| info->key.tun_flags &= ~TUNNEL_CSUM; |
| } |
| |
| return 0; |
| } |
| |
| static const struct bpf_func_proto bpf_skb_set_tunnel_key_proto = { |
| .func = bpf_skb_set_tunnel_key, |
| .gpl_only = false, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_PTR_TO_CTX, |
| .arg2_type = ARG_PTR_TO_STACK, |
| .arg3_type = ARG_CONST_STACK_SIZE, |
| .arg4_type = ARG_ANYTHING, |
| }; |
| |
| static u64 bpf_skb_set_tunnel_opt(u64 r1, u64 r2, u64 size, u64 r4, u64 r5) |
| { |
| struct sk_buff *skb = (struct sk_buff *) (long) r1; |
| u8 *from = (u8 *) (long) r2; |
| struct ip_tunnel_info *info = skb_tunnel_info(skb); |
| const struct metadata_dst *md = this_cpu_ptr(md_dst); |
| |
| if (unlikely(info != &md->u.tun_info || (size & (sizeof(u32) - 1)))) |
| return -EINVAL; |
| if (unlikely(size > IP_TUNNEL_OPTS_MAX)) |
| return -ENOMEM; |
| |
| ip_tunnel_info_opts_set(info, from, size); |
| |
| return 0; |
| } |
| |
| static const struct bpf_func_proto bpf_skb_set_tunnel_opt_proto = { |
| .func = bpf_skb_set_tunnel_opt, |
| .gpl_only = false, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_PTR_TO_CTX, |
| .arg2_type = ARG_PTR_TO_STACK, |
| .arg3_type = ARG_CONST_STACK_SIZE, |
| }; |
| |
| static const struct bpf_func_proto * |
| bpf_get_skb_set_tunnel_proto(enum bpf_func_id which) |
| { |
| if (!md_dst) { |
| /* Race is not possible, since it's called from verifier |
| * that is holding verifier mutex. |
| */ |
| md_dst = metadata_dst_alloc_percpu(IP_TUNNEL_OPTS_MAX, |
| GFP_KERNEL); |
| if (!md_dst) |
| return NULL; |
| } |
| |
| switch (which) { |
| case BPF_FUNC_skb_set_tunnel_key: |
| return &bpf_skb_set_tunnel_key_proto; |
| case BPF_FUNC_skb_set_tunnel_opt: |
| return &bpf_skb_set_tunnel_opt_proto; |
| default: |
| return NULL; |
| } |
| } |
| |
| #ifdef CONFIG_SOCK_CGROUP_DATA |
| static u64 bpf_skb_in_cgroup(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5) |
| { |
| struct sk_buff *skb = (struct sk_buff *)(long)r1; |
| struct bpf_map *map = (struct bpf_map *)(long)r2; |
| struct bpf_array *array = container_of(map, struct bpf_array, map); |
| struct cgroup *cgrp; |
| struct sock *sk; |
| u32 i = (u32)r3; |
| |
| sk = skb->sk; |
| if (!sk || !sk_fullsock(sk)) |
| return -ENOENT; |
| |
| if (unlikely(i >= array->map.max_entries)) |
| return -E2BIG; |
| |
| cgrp = READ_ONCE(array->ptrs[i]); |
| if (unlikely(!cgrp)) |
| return -EAGAIN; |
| |
| return cgroup_is_descendant(sock_cgroup_ptr(&sk->sk_cgrp_data), cgrp); |
| } |
| |
| static const struct bpf_func_proto bpf_skb_in_cgroup_proto = { |
| .func = bpf_skb_in_cgroup, |
| .gpl_only = false, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_PTR_TO_CTX, |
| .arg2_type = ARG_CONST_MAP_PTR, |
| .arg3_type = ARG_ANYTHING, |
| }; |
| #endif |
| |
| static const struct bpf_func_proto * |
| sk_filter_func_proto(enum bpf_func_id func_id) |
| { |
| switch (func_id) { |
| case BPF_FUNC_map_lookup_elem: |
| return &bpf_map_lookup_elem_proto; |
| case BPF_FUNC_map_update_elem: |
| return &bpf_map_update_elem_proto; |
| case BPF_FUNC_map_delete_elem: |
| return &bpf_map_delete_elem_proto; |
| case BPF_FUNC_get_prandom_u32: |
| return &bpf_get_prandom_u32_proto; |
| case BPF_FUNC_get_smp_processor_id: |
| return &bpf_get_raw_smp_processor_id_proto; |
| case BPF_FUNC_tail_call: |
| return &bpf_tail_call_proto; |
| case BPF_FUNC_ktime_get_ns: |
| return &bpf_ktime_get_ns_proto; |
| case BPF_FUNC_trace_printk: |
| if (capable(CAP_SYS_ADMIN)) |
| return bpf_get_trace_printk_proto(); |
| default: |
| return NULL; |
| } |
| } |
| |
| static const struct bpf_func_proto * |
| tc_cls_act_func_proto(enum bpf_func_id func_id) |
| { |
| switch (func_id) { |
| case BPF_FUNC_skb_store_bytes: |
| return &bpf_skb_store_bytes_proto; |
| case BPF_FUNC_skb_load_bytes: |
| return &bpf_skb_load_bytes_proto; |
| case BPF_FUNC_csum_diff: |
| return &bpf_csum_diff_proto; |
| case BPF_FUNC_l3_csum_replace: |
| return &bpf_l3_csum_replace_proto; |
| case BPF_FUNC_l4_csum_replace: |
| return &bpf_l4_csum_replace_proto; |
| case BPF_FUNC_clone_redirect: |
| return &bpf_clone_redirect_proto; |
| case BPF_FUNC_get_cgroup_classid: |
| return &bpf_get_cgroup_classid_proto; |
| case BPF_FUNC_skb_vlan_push: |
| return &bpf_skb_vlan_push_proto; |
| case BPF_FUNC_skb_vlan_pop: |
| return &bpf_skb_vlan_pop_proto; |
| case BPF_FUNC_skb_change_proto: |
| return &bpf_skb_change_proto_proto; |
| case BPF_FUNC_skb_change_type: |
| return &bpf_skb_change_type_proto; |
| case BPF_FUNC_skb_get_tunnel_key: |
| return &bpf_skb_get_tunnel_key_proto; |
| case BPF_FUNC_skb_set_tunnel_key: |
| return bpf_get_skb_set_tunnel_proto(func_id); |
| case BPF_FUNC_skb_get_tunnel_opt: |
| return &bpf_skb_get_tunnel_opt_proto; |
| case BPF_FUNC_skb_set_tunnel_opt: |
| return bpf_get_skb_set_tunnel_proto(func_id); |
| case BPF_FUNC_redirect: |
| return &bpf_redirect_proto; |
| case BPF_FUNC_get_route_realm: |
| return &bpf_get_route_realm_proto; |
| case BPF_FUNC_get_hash_recalc: |
| return &bpf_get_hash_recalc_proto; |
| case BPF_FUNC_perf_event_output: |
| return &bpf_skb_event_output_proto; |
| case BPF_FUNC_get_smp_processor_id: |
| return &bpf_get_smp_processor_id_proto; |
| #ifdef CONFIG_SOCK_CGROUP_DATA |
| case BPF_FUNC_skb_in_cgroup: |
| return &bpf_skb_in_cgroup_proto; |
| #endif |
| default: |
| return sk_filter_func_proto(func_id); |
| } |
| } |
| |
| static const struct bpf_func_proto * |
| xdp_func_proto(enum bpf_func_id func_id) |
| { |
| return sk_filter_func_proto(func_id); |
| } |
| |
| static bool __is_valid_access(int off, int size, enum bpf_access_type type) |
| { |
| if (off < 0 || off >= sizeof(struct __sk_buff)) |
| return false; |
| /* The verifier guarantees that size > 0. */ |
| if (off % size != 0) |
| return false; |
| if (size != sizeof(__u32)) |
| return false; |
| |
| return true; |
| } |
| |
| static bool sk_filter_is_valid_access(int off, int size, |
| enum bpf_access_type type, |
| enum bpf_reg_type *reg_type) |
| { |
| switch (off) { |
| case offsetof(struct __sk_buff, tc_classid): |
| case offsetof(struct __sk_buff, data): |
| case offsetof(struct __sk_buff, data_end): |
| return false; |
| } |
| |
| if (type == BPF_WRITE) { |
| switch (off) { |
| case offsetof(struct __sk_buff, cb[0]) ... |
| offsetof(struct __sk_buff, cb[4]): |
| break; |
| default: |
| return false; |
| } |
| } |
| |
| return __is_valid_access(off, size, type); |
| } |
| |
| static bool tc_cls_act_is_valid_access(int off, int size, |
| enum bpf_access_type type, |
| enum bpf_reg_type *reg_type) |
| { |
| if (type == BPF_WRITE) { |
| switch (off) { |
| case offsetof(struct __sk_buff, mark): |
| case offsetof(struct __sk_buff, tc_index): |
| case offsetof(struct __sk_buff, priority): |
| case offsetof(struct __sk_buff, cb[0]) ... |
| offsetof(struct __sk_buff, cb[4]): |
| case offsetof(struct __sk_buff, tc_classid): |
| break; |
| default: |
| return false; |
| } |
| } |
| |
| switch (off) { |
| case offsetof(struct __sk_buff, data): |
| *reg_type = PTR_TO_PACKET; |
| break; |
| case offsetof(struct __sk_buff, data_end): |
| *reg_type = PTR_TO_PACKET_END; |
| break; |
| } |
| |
| return __is_valid_access(off, size, type); |
| } |
| |
| static bool __is_valid_xdp_access(int off, int size, |
| enum bpf_access_type type) |
| { |
| if (off < 0 || off >= sizeof(struct xdp_md)) |
| return false; |
| if (off % size != 0) |
| return false; |
| if (size != 4) |
| return false; |
| |
| return true; |
| } |
| |
| static bool xdp_is_valid_access(int off, int size, |
| enum bpf_access_type type, |
| enum bpf_reg_type *reg_type) |
| { |
| if (type == BPF_WRITE) |
| return false; |
| |
| switch (off) { |
| case offsetof(struct xdp_md, data): |
| *reg_type = PTR_TO_PACKET; |
| break; |
| case offsetof(struct xdp_md, data_end): |
| *reg_type = PTR_TO_PACKET_END; |
| break; |
| } |
| |
| return __is_valid_xdp_access(off, size, type); |
| } |
| |
| void bpf_warn_invalid_xdp_action(u32 act) |
| { |
| WARN_ONCE(1, "Illegal XDP return value %u, expect packet loss\n", act); |
| } |
| EXPORT_SYMBOL_GPL(bpf_warn_invalid_xdp_action); |
| |
| static u32 bpf_net_convert_ctx_access(enum bpf_access_type type, int dst_reg, |
| int src_reg, int ctx_off, |
| struct bpf_insn *insn_buf, |
| struct bpf_prog *prog) |
| { |
| struct bpf_insn *insn = insn_buf; |
| |
| switch (ctx_off) { |
| case offsetof(struct __sk_buff, len): |
| BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, len) != 4); |
| |
| *insn++ = BPF_LDX_MEM(BPF_W, dst_reg, src_reg, |
| offsetof(struct sk_buff, len)); |
| break; |
| |
| case offsetof(struct __sk_buff, protocol): |
| BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, protocol) != 2); |
| |
| *insn++ = BPF_LDX_MEM(BPF_H, dst_reg, src_reg, |
| offsetof(struct sk_buff, protocol)); |
| break; |
| |
| case offsetof(struct __sk_buff, vlan_proto): |
| BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, vlan_proto) != 2); |
| |
| *insn++ = BPF_LDX_MEM(BPF_H, dst_reg, src_reg, |
| offsetof(struct sk_buff, vlan_proto)); |
| break; |
| |
| case offsetof(struct __sk_buff, priority): |
| BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, priority) != 4); |
| |
| if (type == BPF_WRITE) |
| *insn++ = BPF_STX_MEM(BPF_W, dst_reg, src_reg, |
| offsetof(struct sk_buff, priority)); |
| else |
| *insn++ = BPF_LDX_MEM(BPF_W, dst_reg, src_reg, |
| offsetof(struct sk_buff, priority)); |
| break; |
| |
| case offsetof(struct __sk_buff, ingress_ifindex): |
| BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, skb_iif) != 4); |
| |
| *insn++ = BPF_LDX_MEM(BPF_W, dst_reg, src_reg, |
| offsetof(struct sk_buff, skb_iif)); |
| break; |
| |
| case offsetof(struct __sk_buff, ifindex): |
| BUILD_BUG_ON(FIELD_SIZEOF(struct net_device, ifindex) != 4); |
| |
| *insn++ = BPF_LDX_MEM(bytes_to_bpf_size(FIELD_SIZEOF(struct sk_buff, dev)), |
| dst_reg, src_reg, |
| offsetof(struct sk_buff, dev)); |
| *insn++ = BPF_JMP_IMM(BPF_JEQ, dst_reg, 0, 1); |
| *insn++ = BPF_LDX_MEM(BPF_W, dst_reg, dst_reg, |
| offsetof(struct net_device, ifindex)); |
| break; |
| |
| case offsetof(struct __sk_buff, hash): |
| BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, hash) != 4); |
| |
| *insn++ = BPF_LDX_MEM(BPF_W, dst_reg, src_reg, |
| offsetof(struct sk_buff, hash)); |
| break; |
| |
| case offsetof(struct __sk_buff, mark): |
| BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, mark) != 4); |
| |
| if (type == BPF_WRITE) |
| *insn++ = BPF_STX_MEM(BPF_W, dst_reg, src_reg, |
| offsetof(struct sk_buff, mark)); |
| else |
| *insn++ = BPF_LDX_MEM(BPF_W, dst_reg, src_reg, |
| offsetof(struct sk_buff, mark)); |
| break; |
| |
| case offsetof(struct __sk_buff, pkt_type): |
| return convert_skb_access(SKF_AD_PKTTYPE, dst_reg, src_reg, insn); |
| |
| case offsetof(struct __sk_buff, queue_mapping): |
| return convert_skb_access(SKF_AD_QUEUE, dst_reg, src_reg, insn); |
| |
| case offsetof(struct __sk_buff, vlan_present): |
| return convert_skb_access(SKF_AD_VLAN_TAG_PRESENT, |
| dst_reg, src_reg, insn); |
| |
| case offsetof(struct __sk_buff, vlan_tci): |
| return convert_skb_access(SKF_AD_VLAN_TAG, |
| dst_reg, src_reg, insn); |
| |
| case offsetof(struct __sk_buff, cb[0]) ... |
| offsetof(struct __sk_buff, cb[4]): |
| BUILD_BUG_ON(FIELD_SIZEOF(struct qdisc_skb_cb, data) < 20); |
| |
| prog->cb_access = 1; |
| ctx_off -= offsetof(struct __sk_buff, cb[0]); |
| ctx_off += offsetof(struct sk_buff, cb); |
| ctx_off += offsetof(struct qdisc_skb_cb, data); |
| if (type == BPF_WRITE) |
| *insn++ = BPF_STX_MEM(BPF_W, dst_reg, src_reg, ctx_off); |
| else |
| *insn++ = BPF_LDX_MEM(BPF_W, dst_reg, src_reg, ctx_off); |
| break; |
| |
| case offsetof(struct __sk_buff, tc_classid): |
| ctx_off -= offsetof(struct __sk_buff, tc_classid); |
| ctx_off += offsetof(struct sk_buff, cb); |
| ctx_off += offsetof(struct qdisc_skb_cb, tc_classid); |
| if (type == BPF_WRITE) |
| *insn++ = BPF_STX_MEM(BPF_H, dst_reg, src_reg, ctx_off); |
| else |
| *insn++ = BPF_LDX_MEM(BPF_H, dst_reg, src_reg, ctx_off); |
| break; |
| |
| case offsetof(struct __sk_buff, data): |
| *insn++ = BPF_LDX_MEM(bytes_to_bpf_size(FIELD_SIZEOF(struct sk_buff, data)), |
| dst_reg, src_reg, |
| offsetof(struct sk_buff, data)); |
| break; |
| |
| case offsetof(struct __sk_buff, data_end): |
| ctx_off -= offsetof(struct __sk_buff, data_end); |
| ctx_off += offsetof(struct sk_buff, cb); |
| ctx_off += offsetof(struct bpf_skb_data_end, data_end); |
| *insn++ = BPF_LDX_MEM(bytes_to_bpf_size(sizeof(void *)), |
| dst_reg, src_reg, ctx_off); |
| break; |
| |
| case offsetof(struct __sk_buff, tc_index): |
| #ifdef CONFIG_NET_SCHED |
| BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, tc_index) != 2); |
| |
| if (type == BPF_WRITE) |
| *insn++ = BPF_STX_MEM(BPF_H, dst_reg, src_reg, |
| offsetof(struct sk_buff, tc_index)); |
| else |
| *insn++ = BPF_LDX_MEM(BPF_H, dst_reg, src_reg, |
| offsetof(struct sk_buff, tc_index)); |
| break; |
| #else |
| if (type == BPF_WRITE) |
| *insn++ = BPF_MOV64_REG(dst_reg, dst_reg); |
| else |
| *insn++ = BPF_MOV64_IMM(dst_reg, 0); |
| break; |
| #endif |
| } |
| |
| return insn - insn_buf; |
| } |
| |
| static u32 xdp_convert_ctx_access(enum bpf_access_type type, int dst_reg, |
| int src_reg, int ctx_off, |
| struct bpf_insn *insn_buf, |
| struct bpf_prog *prog) |
| { |
| struct bpf_insn *insn = insn_buf; |
| |
| switch (ctx_off) { |
| case offsetof(struct xdp_md, data): |
| *insn++ = BPF_LDX_MEM(bytes_to_bpf_size(FIELD_SIZEOF(struct xdp_buff, data)), |
| dst_reg, src_reg, |
| offsetof(struct xdp_buff, data)); |
| break; |
| case offsetof(struct xdp_md, data_end): |
| *insn++ = BPF_LDX_MEM(bytes_to_bpf_size(FIELD_SIZEOF(struct xdp_buff, data_end)), |
| dst_reg, src_reg, |
| offsetof(struct xdp_buff, data_end)); |
| break; |
| } |
| |
| return insn - insn_buf; |
| } |
| |
| static const struct bpf_verifier_ops sk_filter_ops = { |
| .get_func_proto = sk_filter_func_proto, |
| .is_valid_access = sk_filter_is_valid_access, |
| .convert_ctx_access = bpf_net_convert_ctx_access, |
| }; |
| |
| static const struct bpf_verifier_ops tc_cls_act_ops = { |
| .get_func_proto = tc_cls_act_func_proto, |
| .is_valid_access = tc_cls_act_is_valid_access, |
| .convert_ctx_access = bpf_net_convert_ctx_access, |
| }; |
| |
| static const struct bpf_verifier_ops xdp_ops = { |
| .get_func_proto = xdp_func_proto, |
| .is_valid_access = xdp_is_valid_access, |
| .convert_ctx_access = xdp_convert_ctx_access, |
| }; |
| |
| static struct bpf_prog_type_list sk_filter_type __read_mostly = { |
| .ops = &sk_filter_ops, |
| .type = BPF_PROG_TYPE_SOCKET_FILTER, |
| }; |
| |
| static struct bpf_prog_type_list sched_cls_type __read_mostly = { |
| .ops = &tc_cls_act_ops, |
| .type = BPF_PROG_TYPE_SCHED_CLS, |
| }; |
| |
| static struct bpf_prog_type_list sched_act_type __read_mostly = { |
| .ops = &tc_cls_act_ops, |
| .type = BPF_PROG_TYPE_SCHED_ACT, |
| }; |
| |
| static struct bpf_prog_type_list xdp_type __read_mostly = { |
| .ops = &xdp_ops, |
| .type = BPF_PROG_TYPE_XDP, |
| }; |
| |
| static int __init register_sk_filter_ops(void) |
| { |
| bpf_register_prog_type(&sk_filter_type); |
| bpf_register_prog_type(&sched_cls_type); |
| bpf_register_prog_type(&sched_act_type); |
| bpf_register_prog_type(&xdp_type); |
| |
| return 0; |
| } |
| late_initcall(register_sk_filter_ops); |
| |
| int sk_detach_filter(struct sock *sk) |
| { |
| int ret = -ENOENT; |
| struct sk_filter *filter; |
| |
| if (sock_flag(sk, SOCK_FILTER_LOCKED)) |
| return -EPERM; |
| |
| filter = rcu_dereference_protected(sk->sk_filter, |
| lockdep_sock_is_held(sk)); |
| if (filter) { |
| RCU_INIT_POINTER(sk->sk_filter, NULL); |
| sk_filter_uncharge(sk, filter); |
| ret = 0; |
| } |
| |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(sk_detach_filter); |
| |
| int sk_get_filter(struct sock *sk, struct sock_filter __user *ubuf, |
| unsigned int len) |
| { |
| struct sock_fprog_kern *fprog; |
| struct sk_filter *filter; |
| int ret = 0; |
| |
| lock_sock(sk); |
| filter = rcu_dereference_protected(sk->sk_filter, |
| lockdep_sock_is_held(sk)); |
| if (!filter) |
| goto out; |
| |
| /* We're copying the filter that has been originally attached, |
| * so no conversion/decode needed anymore. eBPF programs that |
| * have no original program cannot be dumped through this. |
| */ |
| ret = -EACCES; |
| fprog = filter->prog->orig_prog; |
| if (!fprog) |
| goto out; |
| |
| ret = fprog->len; |
| if (!len) |
| /* User space only enquires number of filter blocks. */ |
| goto out; |
| |
| ret = -EINVAL; |
| if (len < fprog->len) |
| goto out; |
| |
| ret = -EFAULT; |
| if (copy_to_user(ubuf, fprog->filter, bpf_classic_proglen(fprog))) |
| goto out; |
| |
| /* Instead of bytes, the API requests to return the number |
| * of filter blocks. |
| */ |
| ret = fprog->len; |
| out: |
| release_sock(sk); |
| return ret; |
| } |