From b0f656184ef249182882dc323babf9e7c8ac3fc0 Mon Sep 17 00:00:00 2001 From: Bhasker Hariharan Date: Mon, 6 Jul 2020 17:21:03 -0700 Subject: Add support for SO_RCVBUF/SO_SNDBUF for AF_PACKET sockets. Updates #2746 PiperOrigin-RevId: 319887810 --- test/syscalls/linux/packet_socket_raw.cc | 273 +++++++++++++++++++++++++++++-- 1 file changed, 260 insertions(+), 13 deletions(-) (limited to 'test') diff --git a/test/syscalls/linux/packet_socket_raw.cc b/test/syscalls/linux/packet_socket_raw.cc index d258d353c..4093ac813 100644 --- a/test/syscalls/linux/packet_socket_raw.cc +++ b/test/syscalls/linux/packet_socket_raw.cc @@ -97,7 +97,7 @@ class RawPacketTest : public ::testing::TestWithParam { int GetLoopbackIndex(); // The socket used for both reading and writing. - int socket_; + int s_; }; void RawPacketTest::SetUp() { @@ -108,34 +108,58 @@ void RawPacketTest::SetUp() { } if (!IsRunningOnGvisor()) { + // Ensure that looped back packets aren't rejected by the kernel. FileDescriptor acceptLocal = ASSERT_NO_ERRNO_AND_VALUE( - Open("/proc/sys/net/ipv4/conf/lo/accept_local", O_RDONLY)); + Open("/proc/sys/net/ipv4/conf/lo/accept_local", O_RDWR)); FileDescriptor routeLocalnet = ASSERT_NO_ERRNO_AND_VALUE( - Open("/proc/sys/net/ipv4/conf/lo/route_localnet", O_RDONLY)); + Open("/proc/sys/net/ipv4/conf/lo/route_localnet", O_RDWR)); char enabled; ASSERT_THAT(read(acceptLocal.get(), &enabled, 1), SyscallSucceedsWithValue(1)); - ASSERT_EQ(enabled, '1'); + if (enabled != '1') { + enabled = '1'; + ASSERT_THAT(lseek(acceptLocal.get(), 0, SEEK_SET), + SyscallSucceedsWithValue(0)); + ASSERT_THAT(write(acceptLocal.get(), &enabled, 1), + SyscallSucceedsWithValue(1)); + ASSERT_THAT(lseek(acceptLocal.get(), 0, SEEK_SET), + SyscallSucceedsWithValue(0)); + ASSERT_THAT(read(acceptLocal.get(), &enabled, 1), + SyscallSucceedsWithValue(1)); + ASSERT_EQ(enabled, '1'); + } + ASSERT_THAT(read(routeLocalnet.get(), &enabled, 1), SyscallSucceedsWithValue(1)); - ASSERT_EQ(enabled, '1'); + if (enabled != '1') { + enabled = '1'; + ASSERT_THAT(lseek(routeLocalnet.get(), 0, SEEK_SET), + SyscallSucceedsWithValue(0)); + ASSERT_THAT(write(routeLocalnet.get(), &enabled, 1), + SyscallSucceedsWithValue(1)); + ASSERT_THAT(lseek(routeLocalnet.get(), 0, SEEK_SET), + SyscallSucceedsWithValue(0)); + ASSERT_THAT(read(routeLocalnet.get(), &enabled, 1), + SyscallSucceedsWithValue(1)); + ASSERT_EQ(enabled, '1'); + } } - ASSERT_THAT(socket_ = socket(AF_PACKET, SOCK_RAW, htons(GetParam())), + ASSERT_THAT(s_ = socket(AF_PACKET, SOCK_RAW, htons(GetParam())), SyscallSucceeds()); } void RawPacketTest::TearDown() { // TearDown will be run even if we skip the test. if (ASSERT_NO_ERRNO_AND_VALUE(HaveCapability(CAP_NET_RAW))) { - EXPECT_THAT(close(socket_), SyscallSucceeds()); + EXPECT_THAT(close(s_), SyscallSucceeds()); } } int RawPacketTest::GetLoopbackIndex() { struct ifreq ifr; snprintf(ifr.ifr_name, IFNAMSIZ, "lo"); - EXPECT_THAT(ioctl(socket_, SIOCGIFINDEX, &ifr), SyscallSucceeds()); + EXPECT_THAT(ioctl(s_, SIOCGIFINDEX, &ifr), SyscallSucceeds()); EXPECT_NE(ifr.ifr_ifindex, 0); return ifr.ifr_ifindex; } @@ -149,7 +173,7 @@ TEST_P(RawPacketTest, Receive) { // Wait for the socket to become readable. struct pollfd pfd = {}; - pfd.fd = socket_; + pfd.fd = s_; pfd.events = POLLIN; EXPECT_THAT(RetryEINTR(poll)(&pfd, 1, 2000), SyscallSucceedsWithValue(1)); @@ -159,7 +183,7 @@ TEST_P(RawPacketTest, Receive) { char buf[64]; struct sockaddr_ll src = {}; socklen_t src_len = sizeof(src); - ASSERT_THAT(recvfrom(socket_, buf, sizeof(buf), 0, + ASSERT_THAT(recvfrom(s_, buf, sizeof(buf), 0, reinterpret_cast(&src), &src_len), SyscallSucceedsWithValue(packet_size)); // sockaddr_ll ends with an 8 byte physical address field, but ethernet @@ -277,7 +301,7 @@ TEST_P(RawPacketTest, Send) { sizeof(kMessage)); // Send it. - ASSERT_THAT(sendto(socket_, send_buf, sizeof(send_buf), 0, + ASSERT_THAT(sendto(s_, send_buf, sizeof(send_buf), 0, reinterpret_cast(&dest), sizeof(dest)), SyscallSucceedsWithValue(sizeof(send_buf))); @@ -286,13 +310,13 @@ TEST_P(RawPacketTest, Send) { pfd.fd = udp_sock.get(); pfd.events = POLLIN; ASSERT_THAT(RetryEINTR(poll)(&pfd, 1, 5000), SyscallSucceedsWithValue(1)); - pfd.fd = socket_; + pfd.fd = s_; pfd.events = POLLIN; ASSERT_THAT(RetryEINTR(poll)(&pfd, 1, 5000), SyscallSucceedsWithValue(1)); // Receive on the packet socket. char recv_buf[sizeof(send_buf)]; - ASSERT_THAT(recv(socket_, recv_buf, sizeof(recv_buf), 0), + ASSERT_THAT(recv(s_, recv_buf, sizeof(recv_buf), 0), SyscallSucceedsWithValue(sizeof(recv_buf))); ASSERT_EQ(memcmp(recv_buf, send_buf, sizeof(send_buf)), 0); @@ -309,6 +333,229 @@ TEST_P(RawPacketTest, Send) { EXPECT_EQ(src.sin_addr.s_addr, htonl(INADDR_LOOPBACK)); } +// Check that setting SO_RCVBUF below min is clamped to the minimum +// receive buffer size. +TEST_P(RawPacketTest, SetSocketRecvBufBelowMin) { + SKIP_IF(!ASSERT_NO_ERRNO_AND_VALUE(HaveCapability(CAP_NET_RAW))); + + // Discover minimum receive buf size by trying to set it to zero. + // See: + // https://github.com/torvalds/linux/blob/a5dc8300df75e8b8384b4c82225f1e4a0b4d9b55/net/core/sock.c#L820 + constexpr int kRcvBufSz = 0; + ASSERT_THAT( + setsockopt(s_, SOL_SOCKET, SO_RCVBUF, &kRcvBufSz, sizeof(kRcvBufSz)), + SyscallSucceeds()); + + int min = 0; + socklen_t min_len = sizeof(min); + ASSERT_THAT(getsockopt(s_, SOL_SOCKET, SO_RCVBUF, &min, &min_len), + SyscallSucceeds()); + + // Linux doubles the value so let's use a value that when doubled will still + // be smaller than min. + int below_min = min / 2 - 1; + ASSERT_THAT( + setsockopt(s_, SOL_SOCKET, SO_RCVBUF, &below_min, sizeof(below_min)), + SyscallSucceeds()); + + int val = 0; + socklen_t val_len = sizeof(val); + ASSERT_THAT(getsockopt(s_, SOL_SOCKET, SO_RCVBUF, &val, &val_len), + SyscallSucceeds()); + + ASSERT_EQ(min, val); +} + +// Check that setting SO_RCVBUF above max is clamped to the maximum +// receive buffer size. +TEST_P(RawPacketTest, SetSocketRecvBufAboveMax) { + SKIP_IF(!ASSERT_NO_ERRNO_AND_VALUE(HaveCapability(CAP_NET_RAW))); + + // Discover max buf size by trying to set the largest possible buffer size. + constexpr int kRcvBufSz = 0xffffffff; + ASSERT_THAT( + setsockopt(s_, SOL_SOCKET, SO_RCVBUF, &kRcvBufSz, sizeof(kRcvBufSz)), + SyscallSucceeds()); + + int max = 0; + socklen_t max_len = sizeof(max); + ASSERT_THAT(getsockopt(s_, SOL_SOCKET, SO_RCVBUF, &max, &max_len), + SyscallSucceeds()); + + int above_max = max + 1; + ASSERT_THAT( + setsockopt(s_, SOL_SOCKET, SO_RCVBUF, &above_max, sizeof(above_max)), + SyscallSucceeds()); + + int val = 0; + socklen_t val_len = sizeof(val); + ASSERT_THAT(getsockopt(s_, SOL_SOCKET, SO_RCVBUF, &val, &val_len), + SyscallSucceeds()); + ASSERT_EQ(max, val); +} + +// Check that setting SO_RCVBUF min <= kRcvBufSz <= max is honored. +TEST_P(RawPacketTest, SetSocketRecvBuf) { + SKIP_IF(!ASSERT_NO_ERRNO_AND_VALUE(HaveCapability(CAP_NET_RAW))); + + int max = 0; + int min = 0; + { + // Discover max buf size by trying to set a really large buffer size. + constexpr int kRcvBufSz = 0xffffffff; + ASSERT_THAT( + setsockopt(s_, SOL_SOCKET, SO_RCVBUF, &kRcvBufSz, sizeof(kRcvBufSz)), + SyscallSucceeds()); + + max = 0; + socklen_t max_len = sizeof(max); + ASSERT_THAT(getsockopt(s_, SOL_SOCKET, SO_RCVBUF, &max, &max_len), + SyscallSucceeds()); + } + + { + // Discover minimum buffer size by trying to set a zero size receive buffer + // size. + // See: + // https://github.com/torvalds/linux/blob/a5dc8300df75e8b8384b4c82225f1e4a0b4d9b55/net/core/sock.c#L820 + constexpr int kRcvBufSz = 0; + ASSERT_THAT( + setsockopt(s_, SOL_SOCKET, SO_RCVBUF, &kRcvBufSz, sizeof(kRcvBufSz)), + SyscallSucceeds()); + + socklen_t min_len = sizeof(min); + ASSERT_THAT(getsockopt(s_, SOL_SOCKET, SO_RCVBUF, &min, &min_len), + SyscallSucceeds()); + } + + int quarter_sz = min + (max - min) / 4; + ASSERT_THAT( + setsockopt(s_, SOL_SOCKET, SO_RCVBUF, &quarter_sz, sizeof(quarter_sz)), + SyscallSucceeds()); + + int val = 0; + socklen_t val_len = sizeof(val); + ASSERT_THAT(getsockopt(s_, SOL_SOCKET, SO_RCVBUF, &val, &val_len), + SyscallSucceeds()); + + // Linux doubles the value set by SO_SNDBUF/SO_RCVBUF. + // TODO(gvisor.dev/issue/2926): Remove when Netstack matches linux behavior. + if (!IsRunningOnGvisor()) { + quarter_sz *= 2; + } + ASSERT_EQ(quarter_sz, val); +} + +// Check that setting SO_SNDBUF below min is clamped to the minimum +// receive buffer size. +TEST_P(RawPacketTest, SetSocketSendBufBelowMin) { + SKIP_IF(!ASSERT_NO_ERRNO_AND_VALUE(HaveCapability(CAP_NET_RAW))); + + // Discover minimum buffer size by trying to set it to zero. + constexpr int kSndBufSz = 0; + ASSERT_THAT( + setsockopt(s_, SOL_SOCKET, SO_SNDBUF, &kSndBufSz, sizeof(kSndBufSz)), + SyscallSucceeds()); + + int min = 0; + socklen_t min_len = sizeof(min); + ASSERT_THAT(getsockopt(s_, SOL_SOCKET, SO_SNDBUF, &min, &min_len), + SyscallSucceeds()); + + // Linux doubles the value so let's use a value that when doubled will still + // be smaller than min. + int below_min = min / 2 - 1; + ASSERT_THAT( + setsockopt(s_, SOL_SOCKET, SO_SNDBUF, &below_min, sizeof(below_min)), + SyscallSucceeds()); + + int val = 0; + socklen_t val_len = sizeof(val); + ASSERT_THAT(getsockopt(s_, SOL_SOCKET, SO_SNDBUF, &val, &val_len), + SyscallSucceeds()); + + ASSERT_EQ(min, val); +} + +// Check that setting SO_SNDBUF above max is clamped to the maximum +// send buffer size. +TEST_P(RawPacketTest, SetSocketSendBufAboveMax) { + SKIP_IF(!ASSERT_NO_ERRNO_AND_VALUE(HaveCapability(CAP_NET_RAW))); + + // Discover maximum buffer size by trying to set it to a large value. + constexpr int kSndBufSz = 0xffffffff; + ASSERT_THAT( + setsockopt(s_, SOL_SOCKET, SO_SNDBUF, &kSndBufSz, sizeof(kSndBufSz)), + SyscallSucceeds()); + + int max = 0; + socklen_t max_len = sizeof(max); + ASSERT_THAT(getsockopt(s_, SOL_SOCKET, SO_SNDBUF, &max, &max_len), + SyscallSucceeds()); + + int above_max = max + 1; + ASSERT_THAT( + setsockopt(s_, SOL_SOCKET, SO_SNDBUF, &above_max, sizeof(above_max)), + SyscallSucceeds()); + + int val = 0; + socklen_t val_len = sizeof(val); + ASSERT_THAT(getsockopt(s_, SOL_SOCKET, SO_SNDBUF, &val, &val_len), + SyscallSucceeds()); + ASSERT_EQ(max, val); +} + +// Check that setting SO_SNDBUF min <= kSndBufSz <= max is honored. +TEST_P(RawPacketTest, SetSocketSendBuf) { + SKIP_IF(!ASSERT_NO_ERRNO_AND_VALUE(HaveCapability(CAP_NET_RAW))); + + int max = 0; + int min = 0; + { + // Discover maximum buffer size by trying to set it to a large value. + constexpr int kSndBufSz = 0xffffffff; + ASSERT_THAT( + setsockopt(s_, SOL_SOCKET, SO_SNDBUF, &kSndBufSz, sizeof(kSndBufSz)), + SyscallSucceeds()); + + max = 0; + socklen_t max_len = sizeof(max); + ASSERT_THAT(getsockopt(s_, SOL_SOCKET, SO_SNDBUF, &max, &max_len), + SyscallSucceeds()); + } + + { + // Discover minimum buffer size by trying to set it to zero. + constexpr int kSndBufSz = 0; + ASSERT_THAT( + setsockopt(s_, SOL_SOCKET, SO_SNDBUF, &kSndBufSz, sizeof(kSndBufSz)), + SyscallSucceeds()); + + socklen_t min_len = sizeof(min); + ASSERT_THAT(getsockopt(s_, SOL_SOCKET, SO_SNDBUF, &min, &min_len), + SyscallSucceeds()); + } + + int quarter_sz = min + (max - min) / 4; + ASSERT_THAT( + setsockopt(s_, SOL_SOCKET, SO_SNDBUF, &quarter_sz, sizeof(quarter_sz)), + SyscallSucceeds()); + + int val = 0; + socklen_t val_len = sizeof(val); + ASSERT_THAT(getsockopt(s_, SOL_SOCKET, SO_SNDBUF, &val, &val_len), + SyscallSucceeds()); + + // Linux doubles the value set by SO_SNDBUF/SO_RCVBUF. + // TODO(gvisor.dev/issue/2926): Remove the gvisor special casing when Netstack + // matches linux behavior. + if (!IsRunningOnGvisor()) { + quarter_sz *= 2; + } + + ASSERT_EQ(quarter_sz, val); +} + INSTANTIATE_TEST_SUITE_P(AllInetTests, RawPacketTest, ::testing::Values(ETH_P_IP, ETH_P_ALL)); -- cgit v1.2.3