diff options
Diffstat (limited to 'tools/testing/selftests/net/reuseaddr_ports_exhausted.c')
| -rw-r--r-- | tools/testing/selftests/net/reuseaddr_ports_exhausted.c | 162 |
1 files changed, 162 insertions, 0 deletions
diff --git a/tools/testing/selftests/net/reuseaddr_ports_exhausted.c b/tools/testing/selftests/net/reuseaddr_ports_exhausted.c new file mode 100644 index 000000000000..7b01b7c2ec10 --- /dev/null +++ b/tools/testing/selftests/net/reuseaddr_ports_exhausted.c @@ -0,0 +1,162 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Check if we can fully utilize 4-tuples for connect(). + * + * Rules to bind sockets to the same port when all ephemeral ports are + * exhausted. + * + * 1. if there are TCP_LISTEN sockets on the port, fail to bind. + * 2. if there are sockets without SO_REUSEADDR, fail to bind. + * 3. if SO_REUSEADDR is disabled, fail to bind. + * 4. if SO_REUSEADDR is enabled and SO_REUSEPORT is disabled, + * succeed to bind. + * 5. if SO_REUSEADDR and SO_REUSEPORT are enabled and + * there is no socket having the both options and the same EUID, + * succeed to bind. + * 6. fail to bind. + * + * Author: Kuniyuki Iwashima <kuniyu@amazon.co.jp> + */ +#include <arpa/inet.h> +#include <netinet/in.h> +#include <sys/socket.h> +#include <sys/types.h> +#include <unistd.h> +#include "../kselftest_harness.h" + +struct reuse_opts { + int reuseaddr[2]; + int reuseport[2]; +}; + +struct reuse_opts unreusable_opts[12] = { + {0, 0, 0, 0}, + {0, 0, 0, 1}, + {0, 0, 1, 0}, + {0, 0, 1, 1}, + {0, 1, 0, 0}, + {0, 1, 0, 1}, + {0, 1, 1, 0}, + {0, 1, 1, 1}, + {1, 0, 0, 0}, + {1, 0, 0, 1}, + {1, 0, 1, 0}, + {1, 0, 1, 1}, +}; + +struct reuse_opts reusable_opts[4] = { + {1, 1, 0, 0}, + {1, 1, 0, 1}, + {1, 1, 1, 0}, + {1, 1, 1, 1}, +}; + +int bind_port(struct __test_metadata *_metadata, int reuseaddr, int reuseport) +{ + struct sockaddr_in local_addr; + int len = sizeof(local_addr); + int fd, ret; + + fd = socket(AF_INET, SOCK_STREAM, 0); + ASSERT_NE(-1, fd) TH_LOG("failed to open socket."); + + ret = setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &reuseaddr, sizeof(int)); + ASSERT_EQ(0, ret) TH_LOG("failed to setsockopt: SO_REUSEADDR."); + + ret = setsockopt(fd, SOL_SOCKET, SO_REUSEPORT, &reuseport, sizeof(int)); + ASSERT_EQ(0, ret) TH_LOG("failed to setsockopt: SO_REUSEPORT."); + + local_addr.sin_family = AF_INET; + local_addr.sin_addr.s_addr = inet_addr("127.0.0.1"); + local_addr.sin_port = 0; + + if (bind(fd, (struct sockaddr *)&local_addr, len) == -1) { + close(fd); + return -1; + } + + return fd; +} + +TEST(reuseaddr_ports_exhausted_unreusable) +{ + struct reuse_opts *opts; + int i, j, fd[2]; + + for (i = 0; i < 12; i++) { + opts = &unreusable_opts[i]; + + for (j = 0; j < 2; j++) + fd[j] = bind_port(_metadata, opts->reuseaddr[j], opts->reuseport[j]); + + ASSERT_NE(-1, fd[0]) TH_LOG("failed to bind."); + EXPECT_EQ(-1, fd[1]) TH_LOG("should fail to bind."); + + for (j = 0; j < 2; j++) + if (fd[j] != -1) + close(fd[j]); + } +} + +TEST(reuseaddr_ports_exhausted_reusable_same_euid) +{ + struct reuse_opts *opts; + int i, j, fd[2]; + + for (i = 0; i < 4; i++) { + opts = &reusable_opts[i]; + + for (j = 0; j < 2; j++) + fd[j] = bind_port(_metadata, opts->reuseaddr[j], opts->reuseport[j]); + + ASSERT_NE(-1, fd[0]) TH_LOG("failed to bind."); + + if (opts->reuseport[0] && opts->reuseport[1]) { + EXPECT_EQ(-1, fd[1]) TH_LOG("should fail to bind because both sockets succeed to be listened."); + } else { + EXPECT_NE(-1, fd[1]) TH_LOG("should succeed to bind to connect to different destinations."); + } + + for (j = 0; j < 2; j++) + if (fd[j] != -1) + close(fd[j]); + } +} + +TEST(reuseaddr_ports_exhausted_reusable_different_euid) +{ + struct reuse_opts *opts; + int i, j, ret, fd[2]; + uid_t euid[2] = {10, 20}; + + for (i = 0; i < 4; i++) { + opts = &reusable_opts[i]; + + for (j = 0; j < 2; j++) { + ret = seteuid(euid[j]); + ASSERT_EQ(0, ret) TH_LOG("failed to seteuid: %d.", euid[j]); + + fd[j] = bind_port(_metadata, opts->reuseaddr[j], opts->reuseport[j]); + + ret = seteuid(0); + ASSERT_EQ(0, ret) TH_LOG("failed to seteuid: 0."); + } + + ASSERT_NE(-1, fd[0]) TH_LOG("failed to bind."); + EXPECT_NE(-1, fd[1]) TH_LOG("should succeed to bind because one socket can be bound in each euid."); + + if (fd[1] != -1) { + ret = listen(fd[0], 5); + ASSERT_EQ(0, ret) TH_LOG("failed to listen."); + + ret = listen(fd[1], 5); + EXPECT_EQ(-1, ret) TH_LOG("should fail to listen because only one uid reserves the port in TCP_LISTEN."); + } + + for (j = 0; j < 2; j++) + if (fd[j] != -1) + close(fd[j]); + } +} + +TEST_HARNESS_MAIN |