Commit a999696c authored by Stanislav Fomichev's avatar Stanislav Fomichev Committed by Alexei Starovoitov

selftests/bpf: Rewrite test_sock_addr bind bpf into C

I'm planning to extend it in the next patches. It's much easier to
work with C than BPF assembly.
Signed-off-by: default avatarStanislav Fomichev <sdf@google.com>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Acked-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20201202172516.3483656-2-sdf@google.com
parent ba058174
// SPDX-License-Identifier: GPL-2.0
#include <string.h>
#include <linux/stddef.h>
#include <linux/bpf.h>
#include <linux/in.h>
#include <linux/in6.h>
#include <sys/socket.h>
#include <netinet/tcp.h>
#include <linux/if.h>
#include <errno.h>
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_endian.h>
#define SERV4_IP 0xc0a801feU /* 192.168.1.254 */
#define SERV4_PORT 4040
#define SERV4_REWRITE_IP 0x7f000001U /* 127.0.0.1 */
#define SERV4_REWRITE_PORT 4444
SEC("cgroup/bind4")
int bind_v4_prog(struct bpf_sock_addr *ctx)
{
struct bpf_sock *sk;
__u32 user_ip4;
__u16 user_port;
sk = ctx->sk;
if (!sk)
return 0;
if (sk->family != AF_INET)
return 0;
if (ctx->type != SOCK_STREAM && ctx->type != SOCK_DGRAM)
return 0;
if (ctx->user_ip4 != bpf_htonl(SERV4_IP) ||
ctx->user_port != bpf_htons(SERV4_PORT))
return 0;
// u8 narrow loads:
user_ip4 = 0;
user_ip4 |= ((volatile __u8 *)&ctx->user_ip4)[0] << 0;
user_ip4 |= ((volatile __u8 *)&ctx->user_ip4)[1] << 8;
user_ip4 |= ((volatile __u8 *)&ctx->user_ip4)[2] << 16;
user_ip4 |= ((volatile __u8 *)&ctx->user_ip4)[3] << 24;
if (ctx->user_ip4 != user_ip4)
return 0;
user_port = 0;
user_port |= ((volatile __u8 *)&ctx->user_port)[0] << 0;
user_port |= ((volatile __u8 *)&ctx->user_port)[1] << 8;
if (ctx->user_port != user_port)
return 0;
// u16 narrow loads:
user_ip4 = 0;
user_ip4 |= ((volatile __u16 *)&ctx->user_ip4)[0] << 0;
user_ip4 |= ((volatile __u16 *)&ctx->user_ip4)[1] << 16;
if (ctx->user_ip4 != user_ip4)
return 0;
ctx->user_ip4 = bpf_htonl(SERV4_REWRITE_IP);
ctx->user_port = bpf_htons(SERV4_REWRITE_PORT);
return 1;
}
char _license[] SEC("license") = "GPL";
// SPDX-License-Identifier: GPL-2.0
#include <string.h>
#include <linux/stddef.h>
#include <linux/bpf.h>
#include <linux/in.h>
#include <linux/in6.h>
#include <sys/socket.h>
#include <netinet/tcp.h>
#include <linux/if.h>
#include <errno.h>
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_endian.h>
#define SERV6_IP_0 0xfaceb00c /* face:b00c:1234:5678::abcd */
#define SERV6_IP_1 0x12345678
#define SERV6_IP_2 0x00000000
#define SERV6_IP_3 0x0000abcd
#define SERV6_PORT 6060
#define SERV6_REWRITE_IP_0 0x00000000
#define SERV6_REWRITE_IP_1 0x00000000
#define SERV6_REWRITE_IP_2 0x00000000
#define SERV6_REWRITE_IP_3 0x00000001
#define SERV6_REWRITE_PORT 6666
SEC("cgroup/bind6")
int bind_v6_prog(struct bpf_sock_addr *ctx)
{
struct bpf_sock *sk;
__u32 user_ip6;
__u16 user_port;
int i;
sk = ctx->sk;
if (!sk)
return 0;
if (sk->family != AF_INET6)
return 0;
if (ctx->type != SOCK_STREAM && ctx->type != SOCK_DGRAM)
return 0;
if (ctx->user_ip6[0] != bpf_htonl(SERV6_IP_0) ||
ctx->user_ip6[1] != bpf_htonl(SERV6_IP_1) ||
ctx->user_ip6[2] != bpf_htonl(SERV6_IP_2) ||
ctx->user_ip6[3] != bpf_htonl(SERV6_IP_3) ||
ctx->user_port != bpf_htons(SERV6_PORT))
return 0;
// u8 narrow loads:
for (i = 0; i < 4; i++) {
user_ip6 = 0;
user_ip6 |= ((volatile __u8 *)&ctx->user_ip6[i])[0] << 0;
user_ip6 |= ((volatile __u8 *)&ctx->user_ip6[i])[1] << 8;
user_ip6 |= ((volatile __u8 *)&ctx->user_ip6[i])[2] << 16;
user_ip6 |= ((volatile __u8 *)&ctx->user_ip6[i])[3] << 24;
if (ctx->user_ip6[i] != user_ip6)
return 0;
}
user_port = 0;
user_port |= ((volatile __u8 *)&ctx->user_port)[0] << 0;
user_port |= ((volatile __u8 *)&ctx->user_port)[1] << 8;
if (ctx->user_port != user_port)
return 0;
// u16 narrow loads:
for (i = 0; i < 4; i++) {
user_ip6 = 0;
user_ip6 |= ((volatile __u16 *)&ctx->user_ip6[i])[0] << 0;
user_ip6 |= ((volatile __u16 *)&ctx->user_ip6[i])[1] << 16;
if (ctx->user_ip6[i] != user_ip6)
return 0;
}
ctx->user_ip6[0] = bpf_htonl(SERV6_REWRITE_IP_0);
ctx->user_ip6[1] = bpf_htonl(SERV6_REWRITE_IP_1);
ctx->user_ip6[2] = bpf_htonl(SERV6_REWRITE_IP_2);
ctx->user_ip6[3] = bpf_htonl(SERV6_REWRITE_IP_3);
ctx->user_port = bpf_htons(SERV6_REWRITE_PORT);
return 1;
}
char _license[] SEC("license") = "GPL";
...@@ -31,6 +31,8 @@ ...@@ -31,6 +31,8 @@
#define CONNECT6_PROG_PATH "./connect6_prog.o" #define CONNECT6_PROG_PATH "./connect6_prog.o"
#define SENDMSG4_PROG_PATH "./sendmsg4_prog.o" #define SENDMSG4_PROG_PATH "./sendmsg4_prog.o"
#define SENDMSG6_PROG_PATH "./sendmsg6_prog.o" #define SENDMSG6_PROG_PATH "./sendmsg6_prog.o"
#define BIND4_PROG_PATH "./bind4_prog.o"
#define BIND6_PROG_PATH "./bind6_prog.o"
#define SERV4_IP "192.168.1.254" #define SERV4_IP "192.168.1.254"
#define SERV4_REWRITE_IP "127.0.0.1" #define SERV4_REWRITE_IP "127.0.0.1"
...@@ -660,190 +662,6 @@ static int load_insns(const struct sock_addr_test *test, ...@@ -660,190 +662,6 @@ static int load_insns(const struct sock_addr_test *test,
return ret; return ret;
} }
/* [1] These testing programs try to read different context fields, including
* narrow loads of different sizes from user_ip4 and user_ip6, and write to
* those allowed to be overridden.
*
* [2] BPF_LD_IMM64 & BPF_JMP_REG are used below whenever there is a need to
* compare a register with unsigned 32bit integer. BPF_JMP_IMM can't be used
* in such cases since it accepts only _signed_ 32bit integer as IMM
* argument. Also note that BPF_LD_IMM64 contains 2 instructions what matters
* to count jumps properly.
*/
static int bind4_prog_load(const struct sock_addr_test *test)
{
union {
uint8_t u4_addr8[4];
uint16_t u4_addr16[2];
uint32_t u4_addr32;
} ip4, port;
struct sockaddr_in addr4_rw;
if (inet_pton(AF_INET, SERV4_IP, (void *)&ip4) != 1) {
log_err("Invalid IPv4: %s", SERV4_IP);
return -1;
}
port.u4_addr32 = htons(SERV4_PORT);
if (mk_sockaddr(AF_INET, SERV4_REWRITE_IP, SERV4_REWRITE_PORT,
(struct sockaddr *)&addr4_rw, sizeof(addr4_rw)) == -1)
return -1;
/* See [1]. */
struct bpf_insn insns[] = {
BPF_MOV64_REG(BPF_REG_6, BPF_REG_1),
/* if (sk.family == AF_INET && */
BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
offsetof(struct bpf_sock_addr, family)),
BPF_JMP_IMM(BPF_JNE, BPF_REG_7, AF_INET, 32),
/* (sk.type == SOCK_DGRAM || sk.type == SOCK_STREAM) && */
BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
offsetof(struct bpf_sock_addr, type)),
BPF_JMP_IMM(BPF_JNE, BPF_REG_7, SOCK_DGRAM, 1),
BPF_JMP_A(1),
BPF_JMP_IMM(BPF_JNE, BPF_REG_7, SOCK_STREAM, 28),
/* 1st_byte_of_user_ip4 == expected && */
BPF_LDX_MEM(BPF_B, BPF_REG_7, BPF_REG_6,
offsetof(struct bpf_sock_addr, user_ip4)),
BPF_JMP_IMM(BPF_JNE, BPF_REG_7, ip4.u4_addr8[0], 26),
/* 2nd_byte_of_user_ip4 == expected && */
BPF_LDX_MEM(BPF_B, BPF_REG_7, BPF_REG_6,
offsetof(struct bpf_sock_addr, user_ip4) + 1),
BPF_JMP_IMM(BPF_JNE, BPF_REG_7, ip4.u4_addr8[1], 24),
/* 3rd_byte_of_user_ip4 == expected && */
BPF_LDX_MEM(BPF_B, BPF_REG_7, BPF_REG_6,
offsetof(struct bpf_sock_addr, user_ip4) + 2),
BPF_JMP_IMM(BPF_JNE, BPF_REG_7, ip4.u4_addr8[2], 22),
/* 4th_byte_of_user_ip4 == expected && */
BPF_LDX_MEM(BPF_B, BPF_REG_7, BPF_REG_6,
offsetof(struct bpf_sock_addr, user_ip4) + 3),
BPF_JMP_IMM(BPF_JNE, BPF_REG_7, ip4.u4_addr8[3], 20),
/* 1st_half_of_user_ip4 == expected && */
BPF_LDX_MEM(BPF_H, BPF_REG_7, BPF_REG_6,
offsetof(struct bpf_sock_addr, user_ip4)),
BPF_JMP_IMM(BPF_JNE, BPF_REG_7, ip4.u4_addr16[0], 18),
/* 2nd_half_of_user_ip4 == expected && */
BPF_LDX_MEM(BPF_H, BPF_REG_7, BPF_REG_6,
offsetof(struct bpf_sock_addr, user_ip4) + 2),
BPF_JMP_IMM(BPF_JNE, BPF_REG_7, ip4.u4_addr16[1], 16),
/* whole_user_ip4 == expected && */
BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
offsetof(struct bpf_sock_addr, user_ip4)),
BPF_LD_IMM64(BPF_REG_8, ip4.u4_addr32), /* See [2]. */
BPF_JMP_REG(BPF_JNE, BPF_REG_7, BPF_REG_8, 12),
/* 1st_byte_of_user_port == expected && */
BPF_LDX_MEM(BPF_B, BPF_REG_7, BPF_REG_6,
offsetof(struct bpf_sock_addr, user_port)),
BPF_JMP_IMM(BPF_JNE, BPF_REG_7, port.u4_addr8[0], 10),
/* 1st_half_of_user_port == expected && */
BPF_LDX_MEM(BPF_H, BPF_REG_7, BPF_REG_6,
offsetof(struct bpf_sock_addr, user_port)),
BPF_JMP_IMM(BPF_JNE, BPF_REG_7, port.u4_addr16[0], 8),
/* user_port == expected) { */
BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
offsetof(struct bpf_sock_addr, user_port)),
BPF_LD_IMM64(BPF_REG_8, port.u4_addr32), /* See [2]. */
BPF_JMP_REG(BPF_JNE, BPF_REG_7, BPF_REG_8, 4),
/* user_ip4 = addr4_rw.sin_addr */
BPF_MOV32_IMM(BPF_REG_7, addr4_rw.sin_addr.s_addr),
BPF_STX_MEM(BPF_W, BPF_REG_6, BPF_REG_7,
offsetof(struct bpf_sock_addr, user_ip4)),
/* user_port = addr4_rw.sin_port */
BPF_MOV32_IMM(BPF_REG_7, addr4_rw.sin_port),
BPF_STX_MEM(BPF_W, BPF_REG_6, BPF_REG_7,
offsetof(struct bpf_sock_addr, user_port)),
/* } */
/* return 1 */
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
};
return load_insns(test, insns, sizeof(insns) / sizeof(struct bpf_insn));
}
static int bind6_prog_load(const struct sock_addr_test *test)
{
struct sockaddr_in6 addr6_rw;
struct in6_addr ip6;
if (inet_pton(AF_INET6, SERV6_IP, (void *)&ip6) != 1) {
log_err("Invalid IPv6: %s", SERV6_IP);
return -1;
}
if (mk_sockaddr(AF_INET6, SERV6_REWRITE_IP, SERV6_REWRITE_PORT,
(struct sockaddr *)&addr6_rw, sizeof(addr6_rw)) == -1)
return -1;
/* See [1]. */
struct bpf_insn insns[] = {
BPF_MOV64_REG(BPF_REG_6, BPF_REG_1),
/* if (sk.family == AF_INET6 && */
BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
offsetof(struct bpf_sock_addr, family)),
BPF_JMP_IMM(BPF_JNE, BPF_REG_7, AF_INET6, 18),
/* 5th_byte_of_user_ip6 == expected && */
BPF_LDX_MEM(BPF_B, BPF_REG_7, BPF_REG_6,
offsetof(struct bpf_sock_addr, user_ip6[1])),
BPF_JMP_IMM(BPF_JNE, BPF_REG_7, ip6.s6_addr[4], 16),
/* 3rd_half_of_user_ip6 == expected && */
BPF_LDX_MEM(BPF_H, BPF_REG_7, BPF_REG_6,
offsetof(struct bpf_sock_addr, user_ip6[1])),
BPF_JMP_IMM(BPF_JNE, BPF_REG_7, ip6.s6_addr16[2], 14),
/* last_word_of_user_ip6 == expected) { */
BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
offsetof(struct bpf_sock_addr, user_ip6[3])),
BPF_LD_IMM64(BPF_REG_8, ip6.s6_addr32[3]), /* See [2]. */
BPF_JMP_REG(BPF_JNE, BPF_REG_7, BPF_REG_8, 10),
#define STORE_IPV6_WORD(N) \
BPF_MOV32_IMM(BPF_REG_7, addr6_rw.sin6_addr.s6_addr32[N]), \
BPF_STX_MEM(BPF_W, BPF_REG_6, BPF_REG_7, \
offsetof(struct bpf_sock_addr, user_ip6[N]))
/* user_ip6 = addr6_rw.sin6_addr */
STORE_IPV6_WORD(0),
STORE_IPV6_WORD(1),
STORE_IPV6_WORD(2),
STORE_IPV6_WORD(3),
/* user_port = addr6_rw.sin6_port */
BPF_MOV32_IMM(BPF_REG_7, addr6_rw.sin6_port),
BPF_STX_MEM(BPF_W, BPF_REG_6, BPF_REG_7,
offsetof(struct bpf_sock_addr, user_port)),
/* } */
/* return 1 */
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
};
return load_insns(test, insns, sizeof(insns) / sizeof(struct bpf_insn));
}
static int load_path(const struct sock_addr_test *test, const char *path) static int load_path(const struct sock_addr_test *test, const char *path)
{ {
struct bpf_prog_load_attr attr; struct bpf_prog_load_attr attr;
...@@ -865,6 +683,16 @@ static int load_path(const struct sock_addr_test *test, const char *path) ...@@ -865,6 +683,16 @@ static int load_path(const struct sock_addr_test *test, const char *path)
return prog_fd; return prog_fd;
} }
static int bind4_prog_load(const struct sock_addr_test *test)
{
return load_path(test, BIND4_PROG_PATH);
}
static int bind6_prog_load(const struct sock_addr_test *test)
{
return load_path(test, BIND6_PROG_PATH);
}
static int connect4_prog_load(const struct sock_addr_test *test) static int connect4_prog_load(const struct sock_addr_test *test)
{ {
return load_path(test, CONNECT4_PROG_PATH); return load_path(test, CONNECT4_PROG_PATH);
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment