diff options
Diffstat (limited to 'net/core/filter.c')
| -rw-r--r-- | net/core/filter.c | 183 |
1 files changed, 91 insertions, 92 deletions
diff --git a/net/core/filter.c b/net/core/filter.c index 42c1944b0c63..d814b8a89d0f 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -18,7 +18,7 @@ * 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 sk_chk_filter() + * Kris Katterjohn - Added many additional checks in bpf_check_classic() */ #include <linux/module.h> @@ -312,7 +312,7 @@ static bool convert_bpf_extensions(struct sock_filter *fp, } /** - * sk_convert_filter - convert filter program + * 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 @@ -322,12 +322,12 @@ static bool convert_bpf_extensions(struct sock_filter *fp, * Conversion workflow: * * 1) First pass for calculating the new program length: - * sk_convert_filter(old_prog, old_len, NULL, &new_len) + * 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); - * sk_convert_filter(old_prog, old_len, new_prog, &new_len); + * bpf_convert_filter(old_prog, old_len, new_prog, &new_len); * * User BPF's register A is mapped to our BPF register 6, user BPF * register X is mapped to BPF register 7; frame pointer is always @@ -335,8 +335,8 @@ static bool convert_bpf_extensions(struct sock_filter *fp, * for socket filters: ctx == 'struct sk_buff *', for seccomp: * ctx == 'struct seccomp_data *'. */ -int sk_convert_filter(struct sock_filter *prog, int len, - struct bpf_insn *new_prog, int *new_len) +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; @@ -721,7 +721,7 @@ static bool chk_code_allowed(u16 code_to_probe) } /** - * sk_chk_filter - verify socket filter code + * bpf_check_classic - verify socket filter code * @filter: filter to verify * @flen: length of filter * @@ -734,7 +734,7 @@ static bool chk_code_allowed(u16 code_to_probe) * * Returns 0 if the rule set is legal or -EINVAL if not. */ -int sk_chk_filter(const struct sock_filter *filter, unsigned int flen) +int bpf_check_classic(const struct sock_filter *filter, unsigned int flen) { bool anc_found; int pc; @@ -808,12 +808,12 @@ int sk_chk_filter(const struct sock_filter *filter, unsigned int flen) return -EINVAL; } -EXPORT_SYMBOL(sk_chk_filter); +EXPORT_SYMBOL(bpf_check_classic); -static int sk_store_orig_filter(struct sk_filter *fp, - const struct sock_fprog *fprog) +static int bpf_prog_store_orig_filter(struct bpf_prog *fp, + const struct sock_fprog *fprog) { - unsigned int fsize = sk_filter_proglen(fprog); + unsigned int fsize = bpf_classic_proglen(fprog); struct sock_fprog_kern *fkprog; fp->orig_prog = kmalloc(sizeof(*fkprog), GFP_KERNEL); @@ -831,7 +831,7 @@ static int sk_store_orig_filter(struct sk_filter *fp, return 0; } -static void sk_release_orig_filter(struct sk_filter *fp) +static void bpf_release_orig_filter(struct bpf_prog *fp) { struct sock_fprog_kern *fprog = fp->orig_prog; @@ -841,10 +841,16 @@ static void sk_release_orig_filter(struct sk_filter *fp) } } +static void __bpf_prog_release(struct bpf_prog *prog) +{ + bpf_release_orig_filter(prog); + bpf_prog_free(prog); +} + static void __sk_filter_release(struct sk_filter *fp) { - sk_release_orig_filter(fp); - sk_filter_free(fp); + __bpf_prog_release(fp->prog); + kfree(fp); } /** @@ -872,44 +878,33 @@ static void sk_filter_release(struct sk_filter *fp) void sk_filter_uncharge(struct sock *sk, struct sk_filter *fp) { - atomic_sub(sk_filter_size(fp->len), &sk->sk_omem_alloc); - sk_filter_release(fp); -} + u32 filter_size = bpf_prog_size(fp->prog->len); -void sk_filter_charge(struct sock *sk, struct sk_filter *fp) -{ - atomic_inc(&fp->refcnt); - atomic_add(sk_filter_size(fp->len), &sk->sk_omem_alloc); + atomic_sub(filter_size, &sk->sk_omem_alloc); + sk_filter_release(fp); } -static struct sk_filter *__sk_migrate_realloc(struct sk_filter *fp, - struct sock *sk, - unsigned int len) +/* 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) { - struct sk_filter *fp_new; - - if (sk == NULL) - return krealloc(fp, len, GFP_KERNEL); - - fp_new = sock_kmalloc(sk, len, GFP_KERNEL); - if (fp_new) { - *fp_new = *fp; - /* As we're keeping orig_prog in fp_new along, - * we need to make sure we're not evicting it - * from the old fp. - */ - fp->orig_prog = NULL; - sk_filter_uncharge(sk, 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 fp_new; + return false; } -static struct sk_filter *__sk_migrate_filter(struct sk_filter *fp, - struct sock *sk) +static struct bpf_prog *bpf_migrate_filter(struct bpf_prog *fp) { struct sock_filter *old_prog; - struct sk_filter *old_fp; + 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 @@ -932,13 +927,13 @@ static struct sk_filter *__sk_migrate_filter(struct sk_filter *fp, } /* 1st pass: calculate the new program length. */ - err = sk_convert_filter(old_prog, old_len, NULL, &new_len); + 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 = __sk_migrate_realloc(old_fp, sk, sk_filter_size(new_len)); + fp = krealloc(old_fp, bpf_prog_size(new_len), GFP_KERNEL); if (!fp) { /* The old_fp is still around in case we couldn't * allocate new memory, so uncharge on that one. @@ -951,16 +946,16 @@ static struct sk_filter *__sk_migrate_filter(struct sk_filter *fp, fp->len = new_len; /* 2nd pass: remap sock_filter insns into bpf_insn insns. */ - err = sk_convert_filter(old_prog, old_len, fp->insnsi, &new_len); + err = bpf_convert_filter(old_prog, old_len, fp->insnsi, &new_len); if (err) - /* 2nd sk_convert_filter() can fail only if it fails + /* 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 __sk_migrate_realloc(). + * by krealloc(). */ goto out_err_free; - sk_filter_select_runtime(fp); + bpf_prog_select_runtime(fp); kfree(old_prog); return fp; @@ -968,28 +963,20 @@ static struct sk_filter *__sk_migrate_filter(struct sk_filter *fp, out_err_free: kfree(old_prog); out_err: - /* Rollback filter setup. */ - if (sk != NULL) - sk_filter_uncharge(sk, fp); - else - kfree(fp); + __bpf_prog_release(fp); return ERR_PTR(err); } -static struct sk_filter *__sk_prepare_filter(struct sk_filter *fp, - struct sock *sk) +static struct bpf_prog *bpf_prepare_filter(struct bpf_prog *fp) { int err; fp->bpf_func = NULL; fp->jited = 0; - err = sk_chk_filter(fp->insns, fp->len); + err = bpf_check_classic(fp->insns, fp->len); if (err) { - if (sk != NULL) - sk_filter_uncharge(sk, fp); - else - kfree(fp); + __bpf_prog_release(fp); return ERR_PTR(err); } @@ -1002,13 +989,13 @@ static struct sk_filter *__sk_prepare_filter(struct sk_filter *fp, * internal BPF translation for the optimized interpreter. */ if (!fp->jited) - fp = __sk_migrate_filter(fp, sk); + fp = bpf_migrate_filter(fp); return fp; } /** - * sk_unattached_filter_create - create an unattached filter + * bpf_prog_create - create an unattached filter * @pfp: the unattached filter that is created * @fprog: the filter program * @@ -1017,23 +1004,21 @@ static struct sk_filter *__sk_prepare_filter(struct sk_filter *fp, * 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_unattached_filter_create(struct sk_filter **pfp, - struct sock_fprog_kern *fprog) +int bpf_prog_create(struct bpf_prog **pfp, struct sock_fprog_kern *fprog) { - unsigned int fsize = sk_filter_proglen(fprog); - struct sk_filter *fp; + unsigned int fsize = bpf_classic_proglen(fprog); + struct bpf_prog *fp; /* Make sure new filter is there and in the right amounts. */ if (fprog->filter == NULL) return -EINVAL; - fp = kmalloc(sk_filter_size(fprog->len), GFP_KERNEL); + fp = kmalloc(bpf_prog_size(fprog->len), GFP_KERNEL); if (!fp) return -ENOMEM; memcpy(fp->insns, fprog->filter, fsize); - atomic_set(&fp->refcnt, 1); fp->len = fprog->len; /* Since unattached filters are not copied back to user * space through sk_get_filter(), we do not need to hold @@ -1041,23 +1026,23 @@ int sk_unattached_filter_create(struct sk_filter **pfp, */ fp->orig_prog = NULL; - /* __sk_prepare_filter() already takes care of uncharging + /* bpf_prepare_filter() already takes care of freeing * memory in case something goes wrong. */ - fp = __sk_prepare_filter(fp, NULL); + fp = bpf_prepare_filter(fp); if (IS_ERR(fp)) return PTR_ERR(fp); *pfp = fp; return 0; } -EXPORT_SYMBOL_GPL(sk_unattached_filter_create); +EXPORT_SYMBOL_GPL(bpf_prog_create); -void sk_unattached_filter_destroy(struct sk_filter *fp) +void bpf_prog_destroy(struct bpf_prog *fp) { - __sk_filter_release(fp); + __bpf_prog_release(fp); } -EXPORT_SYMBOL_GPL(sk_unattached_filter_destroy); +EXPORT_SYMBOL_GPL(bpf_prog_destroy); /** * sk_attach_filter - attach a socket filter @@ -1072,8 +1057,9 @@ EXPORT_SYMBOL_GPL(sk_unattached_filter_destroy); int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk) { struct sk_filter *fp, *old_fp; - unsigned int fsize = sk_filter_proglen(fprog); - unsigned int sk_fsize = sk_filter_size(fprog->len); + unsigned int fsize = bpf_classic_proglen(fprog); + unsigned int bpf_fsize = bpf_prog_size(fprog->len); + struct bpf_prog *prog; int err; if (sock_flag(sk, SOCK_FILTER_LOCKED)) @@ -1083,30 +1069,43 @@ int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk) if (fprog->filter == NULL) return -EINVAL; - fp = sock_kmalloc(sk, sk_fsize, GFP_KERNEL); - if (!fp) + prog = kmalloc(bpf_fsize, GFP_KERNEL); + if (!prog) return -ENOMEM; - if (copy_from_user(fp->insns, fprog->filter, fsize)) { - sock_kfree_s(sk, fp, sk_fsize); + if (copy_from_user(prog->insns, fprog->filter, fsize)) { + kfree(prog); return -EFAULT; } - atomic_set(&fp->refcnt, 1); - fp->len = fprog->len; + prog->len = fprog->len; - err = sk_store_orig_filter(fp, fprog); + err = bpf_prog_store_orig_filter(prog, fprog); if (err) { - sk_filter_uncharge(sk, fp); + kfree(prog); return -ENOMEM; } - /* __sk_prepare_filter() already takes care of uncharging + /* bpf_prepare_filter() already takes care of freeing * memory in case something goes wrong. */ - fp = __sk_prepare_filter(fp, sk); - if (IS_ERR(fp)) - return PTR_ERR(fp); + prog = bpf_prepare_filter(prog); + if (IS_ERR(prog)) + return PTR_ERR(prog); + + fp = kmalloc(sizeof(*fp), GFP_KERNEL); + if (!fp) { + __bpf_prog_release(prog); + return -ENOMEM; + } + fp->prog = prog; + + atomic_set(&fp->refcnt, 0); + + if (!sk_filter_charge(sk, fp)) { + __sk_filter_release(fp); + return -ENOMEM; + } old_fp = rcu_dereference_protected(sk->sk_filter, sock_owned_by_user(sk)); @@ -1155,7 +1154,7 @@ int sk_get_filter(struct sock *sk, struct sock_filter __user *ubuf, /* We're copying the filter that has been originally attached, * so no conversion/decode needed anymore. */ - fprog = filter->orig_prog; + fprog = filter->prog->orig_prog; ret = fprog->len; if (!len) @@ -1167,7 +1166,7 @@ int sk_get_filter(struct sock *sk, struct sock_filter __user *ubuf, goto out; ret = -EFAULT; - if (copy_to_user(ubuf, fprog->filter, sk_filter_proglen(fprog))) + if (copy_to_user(ubuf, fprog->filter, bpf_classic_proglen(fprog))) goto out; /* Instead of bytes, the API requests to return the number |