@@ -35,12 +35,15 @@ struct sock_test {
/* Endpoint to bind() to */
const char *ip;
unsigned short port;
+ unsigned short port_retry;
/* Expected test result */
enum {
LOAD_REJECT,
ATTACH_REJECT,
BIND_REJECT,
SUCCESS,
+ RETRY_SUCCESS,
+ RETRY_REJECT
} result;
};
@@ -251,6 +254,99 @@ static struct sock_test tests[] = {
.port = 4098,
.result = SUCCESS,
},
+ {
+ .descr = "bind4 deny specific IP & port of TCP, and retry",
+ .insns = {
+ BPF_MOV64_REG(BPF_REG_6, BPF_REG_1),
+
+ /* if (ip == expected && port == expected) */
+ BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
+ offsetof(struct bpf_sock, src_ip4)),
+ BPF_JMP_IMM(BPF_JNE, BPF_REG_7,
+ __bpf_constant_ntohl(0x7F000001), 4),
+ BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
+ offsetof(struct bpf_sock, src_port)),
+ BPF_JMP_IMM(BPF_JNE, BPF_REG_7, 0x1002, 2),
+
+ /* return DENY; */
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_JMP_A(1),
+
+ /* else return ALLOW; */
+ BPF_MOV64_IMM(BPF_REG_0, 1),
+ BPF_EXIT_INSN(),
+ },
+ .expected_attach_type = BPF_CGROUP_INET4_POST_BIND,
+ .attach_type = BPF_CGROUP_INET4_POST_BIND,
+ .domain = AF_INET,
+ .type = SOCK_STREAM,
+ .ip = "127.0.0.1",
+ .port = 4098,
+ .port_retry = 5000,
+ .result = RETRY_SUCCESS,
+ },
+ {
+ .descr = "bind4 deny specific IP & port of UDP, and retry",
+ .insns = {
+ BPF_MOV64_REG(BPF_REG_6, BPF_REG_1),
+
+ /* if (ip == expected && port == expected) */
+ BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
+ offsetof(struct bpf_sock, src_ip4)),
+ BPF_JMP_IMM(BPF_JNE, BPF_REG_7,
+ __bpf_constant_ntohl(0x7F000001), 4),
+ BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
+ offsetof(struct bpf_sock, src_port)),
+ BPF_JMP_IMM(BPF_JNE, BPF_REG_7, 0x1002, 2),
+
+ /* return DENY; */
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_JMP_A(1),
+
+ /* else return ALLOW; */
+ BPF_MOV64_IMM(BPF_REG_0, 1),
+ BPF_EXIT_INSN(),
+ },
+ .expected_attach_type = BPF_CGROUP_INET4_POST_BIND,
+ .attach_type = BPF_CGROUP_INET4_POST_BIND,
+ .domain = AF_INET,
+ .type = SOCK_DGRAM,
+ .ip = "127.0.0.1",
+ .port = 4098,
+ .port_retry = 5000,
+ .result = RETRY_SUCCESS,
+ },
+ {
+ .descr = "bind6 deny specific IP & port, and retry",
+ .insns = {
+ BPF_MOV64_REG(BPF_REG_6, BPF_REG_1),
+
+ /* if (ip == expected && port == expected) */
+ BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
+ offsetof(struct bpf_sock, src_ip6[3])),
+ BPF_JMP_IMM(BPF_JNE, BPF_REG_7,
+ __bpf_constant_ntohl(0x00000001), 4),
+ BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
+ offsetof(struct bpf_sock, src_port)),
+ BPF_JMP_IMM(BPF_JNE, BPF_REG_7, 0x2001, 2),
+
+ /* return DENY; */
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_JMP_A(1),
+
+ /* else return ALLOW; */
+ BPF_MOV64_IMM(BPF_REG_0, 1),
+ BPF_EXIT_INSN(),
+ },
+ .expected_attach_type = BPF_CGROUP_INET6_POST_BIND,
+ .attach_type = BPF_CGROUP_INET6_POST_BIND,
+ .domain = AF_INET6,
+ .type = SOCK_STREAM,
+ .ip = "::1",
+ .port = 8193,
+ .port_retry = 9000,
+ .result = RETRY_SUCCESS,
+ },
{
.descr = "bind4 allow all",
.insns = {
@@ -315,14 +411,15 @@ static int attach_sock_prog(int cgfd, int progfd,
return bpf_prog_attach(progfd, cgfd, attach_type, BPF_F_ALLOW_OVERRIDE);
}
-static int bind_sock(int domain, int type, const char *ip, unsigned short port)
+static int bind_sock(int domain, int type, const char *ip,
+ unsigned short port, unsigned short port_retry)
{
struct sockaddr_storage addr;
struct sockaddr_in6 *addr6;
struct sockaddr_in *addr4;
int sockfd = -1;
socklen_t len;
- int err = 0;
+ int res = SUCCESS;
sockfd = socket(domain, type, 0);
if (sockfd < 0)
@@ -348,21 +445,44 @@ static int bind_sock(int domain, int type, const char *ip, unsigned short port)
goto err;
}
- if (bind(sockfd, (const struct sockaddr *)&addr, len) == -1)
- goto err;
+ if (bind(sockfd, (const struct sockaddr *)&addr, len) == -1) {
+ /* sys_bind() may fail for different reasons, errno has to be
+ * checked to confirm that BPF program rejected it.
+ */
+ if (errno != EPERM)
+ goto err;
+ if (port_retry)
+ goto retry;
+ res = BIND_REJECT;
+ goto out;
+ }
+ goto out;
+retry:
+ if (domain == AF_INET)
+ addr4->sin_port = htons(port_retry);
+ else
+ addr6->sin6_port = htons(port_retry);
+ if (bind(sockfd, (const struct sockaddr *)&addr, len) == -1) {
+ if (errno != EPERM)
+ goto err;
+ res = RETRY_REJECT;
+ } else {
+ res = RETRY_SUCCESS;
+ }
goto out;
err:
- err = -1;
+ res = -1;
out:
close(sockfd);
- return err;
+ return res;
}
static int run_test_case(int cgfd, const struct sock_test *test)
{
int progfd = -1;
int err = 0;
+ int res;
printf("Test case: %s .. ", test->descr);
progfd = load_sock_prog(test->insns, test->expected_attach_type);
@@ -380,21 +500,11 @@ static int run_test_case(int cgfd, const struct sock_test *test)
goto err;
}
- if (bind_sock(test->domain, test->type, test->ip, test->port) == -1) {
- /* sys_bind() may fail for different reasons, errno has to be
- * checked to confirm that BPF program rejected it.
- */
- if (test->result == BIND_REJECT && errno == EPERM)
- goto out;
- else
- goto err;
- }
-
+ res = bind_sock(test->domain, test->type, test->ip, test->port,
+ test->port_retry);
+ if (res > 0 && test->result == res)
+ goto out;
- if (test->result != SUCCESS)
- goto err;
-
- goto out;
err:
err = -1;
out: