diff options
Diffstat (limited to 'net/core/filter.c')
| -rw-r--r-- | net/core/filter.c | 130 |
1 files changed, 130 insertions, 0 deletions
diff --git a/net/core/filter.c b/net/core/filter.c index 5a114d41bf1..c23543cba13 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -760,3 +760,133 @@ int sk_detach_filter(struct sock *sk) return ret; } EXPORT_SYMBOL_GPL(sk_detach_filter); + +static void sk_decode_filter(struct sock_filter *filt, struct sock_filter *to) +{ + static const u16 decodes[] = { + [BPF_S_ALU_ADD_K] = BPF_ALU|BPF_ADD|BPF_K, + [BPF_S_ALU_ADD_X] = BPF_ALU|BPF_ADD|BPF_X, + [BPF_S_ALU_SUB_K] = BPF_ALU|BPF_SUB|BPF_K, + [BPF_S_ALU_SUB_X] = BPF_ALU|BPF_SUB|BPF_X, + [BPF_S_ALU_MUL_K] = BPF_ALU|BPF_MUL|BPF_K, + [BPF_S_ALU_MUL_X] = BPF_ALU|BPF_MUL|BPF_X, + [BPF_S_ALU_DIV_X] = BPF_ALU|BPF_DIV|BPF_X, + [BPF_S_ALU_MOD_K] = BPF_ALU|BPF_MOD|BPF_K, + [BPF_S_ALU_MOD_X] = BPF_ALU|BPF_MOD|BPF_X, + [BPF_S_ALU_AND_K] = BPF_ALU|BPF_AND|BPF_K, + [BPF_S_ALU_AND_X] = BPF_ALU|BPF_AND|BPF_X, + [BPF_S_ALU_OR_K] = BPF_ALU|BPF_OR|BPF_K, + [BPF_S_ALU_OR_X] = BPF_ALU|BPF_OR|BPF_X, + [BPF_S_ALU_XOR_K] = BPF_ALU|BPF_XOR|BPF_K, + [BPF_S_ALU_XOR_X] = BPF_ALU|BPF_XOR|BPF_X, + [BPF_S_ALU_LSH_K] = BPF_ALU|BPF_LSH|BPF_K, + [BPF_S_ALU_LSH_X] = BPF_ALU|BPF_LSH|BPF_X, + [BPF_S_ALU_RSH_K] = BPF_ALU|BPF_RSH|BPF_K, + [BPF_S_ALU_RSH_X] = BPF_ALU|BPF_RSH|BPF_X, + [BPF_S_ALU_NEG] = BPF_ALU|BPF_NEG, + [BPF_S_LD_W_ABS] = BPF_LD|BPF_W|BPF_ABS, + [BPF_S_LD_H_ABS] = BPF_LD|BPF_H|BPF_ABS, + [BPF_S_LD_B_ABS] = BPF_LD|BPF_B|BPF_ABS, + [BPF_S_ANC_PROTOCOL] = BPF_LD|BPF_B|BPF_ABS, + [BPF_S_ANC_PKTTYPE] = BPF_LD|BPF_B|BPF_ABS, + [BPF_S_ANC_IFINDEX] = BPF_LD|BPF_B|BPF_ABS, + [BPF_S_ANC_NLATTR] = BPF_LD|BPF_B|BPF_ABS, + [BPF_S_ANC_NLATTR_NEST] = BPF_LD|BPF_B|BPF_ABS, + [BPF_S_ANC_MARK] = BPF_LD|BPF_B|BPF_ABS, + [BPF_S_ANC_QUEUE] = BPF_LD|BPF_B|BPF_ABS, + [BPF_S_ANC_HATYPE] = BPF_LD|BPF_B|BPF_ABS, + [BPF_S_ANC_RXHASH] = BPF_LD|BPF_B|BPF_ABS, + [BPF_S_ANC_CPU] = BPF_LD|BPF_B|BPF_ABS, + [BPF_S_ANC_ALU_XOR_X] = BPF_LD|BPF_B|BPF_ABS, + [BPF_S_ANC_SECCOMP_LD_W] = BPF_LD|BPF_B|BPF_ABS, + [BPF_S_ANC_VLAN_TAG] = BPF_LD|BPF_B|BPF_ABS, + [BPF_S_ANC_VLAN_TAG_PRESENT] = BPF_LD|BPF_B|BPF_ABS, + [BPF_S_LD_W_LEN] = BPF_LD|BPF_W|BPF_LEN, + [BPF_S_LD_W_IND] = BPF_LD|BPF_W|BPF_IND, + [BPF_S_LD_H_IND] = BPF_LD|BPF_H|BPF_IND, + [BPF_S_LD_B_IND] = BPF_LD|BPF_B|BPF_IND, + [BPF_S_LD_IMM] = BPF_LD|BPF_IMM, + [BPF_S_LDX_W_LEN] = BPF_LDX|BPF_W|BPF_LEN, + [BPF_S_LDX_B_MSH] = BPF_LDX|BPF_B|BPF_MSH, + [BPF_S_LDX_IMM] = BPF_LDX|BPF_IMM, + [BPF_S_MISC_TAX] = BPF_MISC|BPF_TAX, + [BPF_S_MISC_TXA] = BPF_MISC|BPF_TXA, + [BPF_S_RET_K] = BPF_RET|BPF_K, + [BPF_S_RET_A] = BPF_RET|BPF_A, + [BPF_S_ALU_DIV_K] = BPF_ALU|BPF_DIV|BPF_K, + [BPF_S_LD_MEM] = BPF_LD|BPF_MEM, + [BPF_S_LDX_MEM] = BPF_LDX|BPF_MEM, + [BPF_S_ST] = BPF_ST, + [BPF_S_STX] = BPF_STX, + [BPF_S_JMP_JA] = BPF_JMP|BPF_JA, + [BPF_S_JMP_JEQ_K] = BPF_JMP|BPF_JEQ|BPF_K, + [BPF_S_JMP_JEQ_X] = BPF_JMP|BPF_JEQ|BPF_X, + [BPF_S_JMP_JGE_K] = BPF_JMP|BPF_JGE|BPF_K, + [BPF_S_JMP_JGE_X] = BPF_JMP|BPF_JGE|BPF_X, + [BPF_S_JMP_JGT_K] = BPF_JMP|BPF_JGT|BPF_K, + [BPF_S_JMP_JGT_X] = BPF_JMP|BPF_JGT|BPF_X, + [BPF_S_JMP_JSET_K] = BPF_JMP|BPF_JSET|BPF_K, + [BPF_S_JMP_JSET_X] = BPF_JMP|BPF_JSET|BPF_X, + }; + u16 code; + + code = filt->code; + + to->code = decodes[code]; + to->jt = filt->jt; + to->jf = filt->jf; + + if (code == BPF_S_ALU_DIV_K) { + /* + * When loaded this rule user gave us X, which was + * translated into R = r(X). Now we calculate the + * RR = r(R) and report it back. If next time this + * value is loaded and RRR = r(RR) is calculated + * then the R == RRR will be true. + * + * One exception. X == 1 translates into R == 0 and + * we can't calculate RR out of it with r(). + */ + + if (filt->k == 0) + to->k = 1; + else + to->k = reciprocal_value(filt->k); + + BUG_ON(reciprocal_value(to->k) != filt->k); + } else + to->k = filt->k; +} + +int sk_get_filter(struct sock *sk, struct sock_filter __user *ubuf, unsigned int len) +{ + struct sk_filter *filter; + int i, ret; + + lock_sock(sk); + filter = rcu_dereference_protected(sk->sk_filter, + sock_owned_by_user(sk)); + ret = 0; + if (!filter) + goto out; + ret = filter->len; + if (!len) + goto out; + ret = -EINVAL; + if (len < filter->len) + goto out; + + ret = -EFAULT; + for (i = 0; i < filter->len; i++) { + struct sock_filter fb; + + sk_decode_filter(&filter->insns[i], &fb); + if (copy_to_user(&ubuf[i], &fb, sizeof(fb))) + goto out; + } + + ret = filter->len; +out: + release_sock(sk); + return ret; +} |