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bpf: Factor out attach_type to prog_type mapping for attach/detach
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Factor out logic mapping expected program attach type to program type and
subsequent handling of program attach/detach. Also list out all supported
cgroup BPF program types explicitly to prevent accidental bugs once more
program types are added to a mapping. Do the same for prog_query API.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200325065746.640559-3-andriin@fb.com
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Andrii Nakryiko authored and Alexei Starovoitov committed Mar 26, 2020
1 parent 00c4edd commit e28784e
Showing 1 changed file with 66 additions and 87 deletions.
153 changes: 66 additions & 87 deletions kernel/bpf/syscall.c
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Original file line number Diff line number Diff line change
Expand Up @@ -2535,36 +2535,18 @@ static int bpf_prog_attach_check_attach_type(const struct bpf_prog *prog,
}
}

#define BPF_PROG_ATTACH_LAST_FIELD replace_bpf_fd

#define BPF_F_ATTACH_MASK \
(BPF_F_ALLOW_OVERRIDE | BPF_F_ALLOW_MULTI | BPF_F_REPLACE)

static int bpf_prog_attach(const union bpf_attr *attr)
static enum bpf_prog_type
attach_type_to_prog_type(enum bpf_attach_type attach_type)
{
enum bpf_prog_type ptype;
struct bpf_prog *prog;
int ret;

if (!capable(CAP_NET_ADMIN))
return -EPERM;

if (CHECK_ATTR(BPF_PROG_ATTACH))
return -EINVAL;

if (attr->attach_flags & ~BPF_F_ATTACH_MASK)
return -EINVAL;

switch (attr->attach_type) {
switch (attach_type) {
case BPF_CGROUP_INET_INGRESS:
case BPF_CGROUP_INET_EGRESS:
ptype = BPF_PROG_TYPE_CGROUP_SKB;
return BPF_PROG_TYPE_CGROUP_SKB;
break;
case BPF_CGROUP_INET_SOCK_CREATE:
case BPF_CGROUP_INET4_POST_BIND:
case BPF_CGROUP_INET6_POST_BIND:
ptype = BPF_PROG_TYPE_CGROUP_SOCK;
break;
return BPF_PROG_TYPE_CGROUP_SOCK;
case BPF_CGROUP_INET4_BIND:
case BPF_CGROUP_INET6_BIND:
case BPF_CGROUP_INET4_CONNECT:
Expand All @@ -2573,37 +2555,53 @@ static int bpf_prog_attach(const union bpf_attr *attr)
case BPF_CGROUP_UDP6_SENDMSG:
case BPF_CGROUP_UDP4_RECVMSG:
case BPF_CGROUP_UDP6_RECVMSG:
ptype = BPF_PROG_TYPE_CGROUP_SOCK_ADDR;
break;
return BPF_PROG_TYPE_CGROUP_SOCK_ADDR;
case BPF_CGROUP_SOCK_OPS:
ptype = BPF_PROG_TYPE_SOCK_OPS;
break;
return BPF_PROG_TYPE_SOCK_OPS;
case BPF_CGROUP_DEVICE:
ptype = BPF_PROG_TYPE_CGROUP_DEVICE;
break;
return BPF_PROG_TYPE_CGROUP_DEVICE;
case BPF_SK_MSG_VERDICT:
ptype = BPF_PROG_TYPE_SK_MSG;
break;
return BPF_PROG_TYPE_SK_MSG;
case BPF_SK_SKB_STREAM_PARSER:
case BPF_SK_SKB_STREAM_VERDICT:
ptype = BPF_PROG_TYPE_SK_SKB;
break;
return BPF_PROG_TYPE_SK_SKB;
case BPF_LIRC_MODE2:
ptype = BPF_PROG_TYPE_LIRC_MODE2;
break;
return BPF_PROG_TYPE_LIRC_MODE2;
case BPF_FLOW_DISSECTOR:
ptype = BPF_PROG_TYPE_FLOW_DISSECTOR;
break;
return BPF_PROG_TYPE_FLOW_DISSECTOR;
case BPF_CGROUP_SYSCTL:
ptype = BPF_PROG_TYPE_CGROUP_SYSCTL;
break;
return BPF_PROG_TYPE_CGROUP_SYSCTL;
case BPF_CGROUP_GETSOCKOPT:
case BPF_CGROUP_SETSOCKOPT:
ptype = BPF_PROG_TYPE_CGROUP_SOCKOPT;
break;
return BPF_PROG_TYPE_CGROUP_SOCKOPT;
default:
return -EINVAL;
return BPF_PROG_TYPE_UNSPEC;
}
}

#define BPF_PROG_ATTACH_LAST_FIELD replace_bpf_fd

#define BPF_F_ATTACH_MASK \
(BPF_F_ALLOW_OVERRIDE | BPF_F_ALLOW_MULTI | BPF_F_REPLACE)

static int bpf_prog_attach(const union bpf_attr *attr)
{
enum bpf_prog_type ptype;
struct bpf_prog *prog;
int ret;

if (!capable(CAP_NET_ADMIN))
return -EPERM;

if (CHECK_ATTR(BPF_PROG_ATTACH))
return -EINVAL;

if (attr->attach_flags & ~BPF_F_ATTACH_MASK)
return -EINVAL;

ptype = attach_type_to_prog_type(attr->attach_type);
if (ptype == BPF_PROG_TYPE_UNSPEC)
return -EINVAL;

prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype);
if (IS_ERR(prog))
Expand All @@ -2625,8 +2623,17 @@ static int bpf_prog_attach(const union bpf_attr *attr)
case BPF_PROG_TYPE_FLOW_DISSECTOR:
ret = skb_flow_dissector_bpf_prog_attach(attr, prog);
break;
default:
case BPF_PROG_TYPE_CGROUP_DEVICE:
case BPF_PROG_TYPE_CGROUP_SKB:
case BPF_PROG_TYPE_CGROUP_SOCK:
case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
case BPF_PROG_TYPE_CGROUP_SOCKOPT:
case BPF_PROG_TYPE_CGROUP_SYSCTL:
case BPF_PROG_TYPE_SOCK_OPS:
ret = cgroup_bpf_prog_attach(attr, ptype, prog);
break;
default:
ret = -EINVAL;
}

if (ret)
Expand All @@ -2646,53 +2653,27 @@ static int bpf_prog_detach(const union bpf_attr *attr)
if (CHECK_ATTR(BPF_PROG_DETACH))
return -EINVAL;

switch (attr->attach_type) {
case BPF_CGROUP_INET_INGRESS:
case BPF_CGROUP_INET_EGRESS:
ptype = BPF_PROG_TYPE_CGROUP_SKB;
break;
case BPF_CGROUP_INET_SOCK_CREATE:
case BPF_CGROUP_INET4_POST_BIND:
case BPF_CGROUP_INET6_POST_BIND:
ptype = BPF_PROG_TYPE_CGROUP_SOCK;
break;
case BPF_CGROUP_INET4_BIND:
case BPF_CGROUP_INET6_BIND:
case BPF_CGROUP_INET4_CONNECT:
case BPF_CGROUP_INET6_CONNECT:
case BPF_CGROUP_UDP4_SENDMSG:
case BPF_CGROUP_UDP6_SENDMSG:
case BPF_CGROUP_UDP4_RECVMSG:
case BPF_CGROUP_UDP6_RECVMSG:
ptype = BPF_PROG_TYPE_CGROUP_SOCK_ADDR;
break;
case BPF_CGROUP_SOCK_OPS:
ptype = BPF_PROG_TYPE_SOCK_OPS;
break;
case BPF_CGROUP_DEVICE:
ptype = BPF_PROG_TYPE_CGROUP_DEVICE;
break;
case BPF_SK_MSG_VERDICT:
return sock_map_get_from_fd(attr, NULL);
case BPF_SK_SKB_STREAM_PARSER:
case BPF_SK_SKB_STREAM_VERDICT:
ptype = attach_type_to_prog_type(attr->attach_type);

switch (ptype) {
case BPF_PROG_TYPE_SK_MSG:
case BPF_PROG_TYPE_SK_SKB:
return sock_map_get_from_fd(attr, NULL);
case BPF_LIRC_MODE2:
case BPF_PROG_TYPE_LIRC_MODE2:
return lirc_prog_detach(attr);
case BPF_FLOW_DISSECTOR:
case BPF_PROG_TYPE_FLOW_DISSECTOR:
return skb_flow_dissector_bpf_prog_detach(attr);
case BPF_CGROUP_SYSCTL:
ptype = BPF_PROG_TYPE_CGROUP_SYSCTL;
break;
case BPF_CGROUP_GETSOCKOPT:
case BPF_CGROUP_SETSOCKOPT:
ptype = BPF_PROG_TYPE_CGROUP_SOCKOPT;
break;
case BPF_PROG_TYPE_CGROUP_DEVICE:
case BPF_PROG_TYPE_CGROUP_SKB:
case BPF_PROG_TYPE_CGROUP_SOCK:
case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
case BPF_PROG_TYPE_CGROUP_SOCKOPT:
case BPF_PROG_TYPE_CGROUP_SYSCTL:
case BPF_PROG_TYPE_SOCK_OPS:
return cgroup_bpf_prog_detach(attr, ptype);
default:
return -EINVAL;
}

return cgroup_bpf_prog_detach(attr, ptype);
}

#define BPF_PROG_QUERY_LAST_FIELD query.prog_cnt
Expand Down Expand Up @@ -2726,16 +2707,14 @@ static int bpf_prog_query(const union bpf_attr *attr,
case BPF_CGROUP_SYSCTL:
case BPF_CGROUP_GETSOCKOPT:
case BPF_CGROUP_SETSOCKOPT:
break;
return cgroup_bpf_prog_query(attr, uattr);
case BPF_LIRC_MODE2:
return lirc_prog_query(attr, uattr);
case BPF_FLOW_DISSECTOR:
return skb_flow_dissector_prog_query(attr, uattr);
default:
return -EINVAL;
}

return cgroup_bpf_prog_query(attr, uattr);
}

#define BPF_PROG_TEST_RUN_LAST_FIELD test.ctx_out
Expand Down

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