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-rw-r--r--pkg/sentry/fs/proc/BUILD1
-rw-r--r--pkg/sentry/fs/proc/net.go169
-rw-r--r--test/syscalls/linux/BUILD15
-rw-r--r--test/syscalls/linux/proc_net_tcp.cc281
-rw-r--r--test/syscalls/linux/proc_net_unix.cc5
5 files changed, 457 insertions, 14 deletions
diff --git a/pkg/sentry/fs/proc/BUILD b/pkg/sentry/fs/proc/BUILD
index b70c583f3..da41a10ab 100644
--- a/pkg/sentry/fs/proc/BUILD
+++ b/pkg/sentry/fs/proc/BUILD
@@ -31,6 +31,7 @@ go_library(
visibility = ["//pkg/sentry:internal"],
deps = [
"//pkg/abi/linux",
+ "//pkg/binary",
"//pkg/log",
"//pkg/sentry/context",
"//pkg/sentry/fs",
diff --git a/pkg/sentry/fs/proc/net.go b/pkg/sentry/fs/proc/net.go
index caa1a5c4d..37694620c 100644
--- a/pkg/sentry/fs/proc/net.go
+++ b/pkg/sentry/fs/proc/net.go
@@ -20,6 +20,7 @@ import (
"time"
"gvisor.dev/gvisor/pkg/abi/linux"
+ "gvisor.dev/gvisor/pkg/binary"
"gvisor.dev/gvisor/pkg/log"
"gvisor.dev/gvisor/pkg/sentry/context"
"gvisor.dev/gvisor/pkg/sentry/fs"
@@ -55,9 +56,8 @@ func (p *proc) newNetDir(ctx context.Context, k *kernel.Kernel, msrc *fs.MountSo
"psched": newStaticProcInode(ctx, msrc, []byte(fmt.Sprintf("%08x %08x %08x %08x\n", uint64(time.Microsecond/time.Nanosecond), 64, 1000000, uint64(time.Second/time.Nanosecond)))),
"ptype": newStaticProcInode(ctx, msrc, []byte("Type Device Function")),
"route": newStaticProcInode(ctx, msrc, []byte("Iface Destination Gateway Flags RefCnt Use Metric Mask MTU Window IRTT")),
- "tcp": newStaticProcInode(ctx, msrc, []byte(" sl local_address rem_address st tx_queue rx_queue tr tm->when retrnsmt uid timeout inode")),
-
- "udp": newStaticProcInode(ctx, msrc, []byte(" sl local_address rem_address st tx_queue rx_queue tr tm->when retrnsmt uid timeout inode ref pointer drops")),
+ "tcp": seqfile.NewSeqFileInode(ctx, &netTCP{k: k}, msrc),
+ "udp": newStaticProcInode(ctx, msrc, []byte(" sl local_address rem_address st tx_queue rx_queue tr tm->when retrnsmt uid timeout inode ref pointer drops")),
"unix": seqfile.NewSeqFileInode(ctx, &netUnix{k: k}, msrc),
}
@@ -210,10 +210,6 @@ func (n *netUnix) ReadSeqFileData(ctx context.Context, h seqfile.SeqHandle) ([]s
}
var buf bytes.Buffer
- // Header
- fmt.Fprintf(&buf, "Num RefCount Protocol Flags Type St Inode Path\n")
-
- // Entries
for _, se := range n.k.ListSockets() {
s := se.Sock.Get()
if s == nil {
@@ -222,6 +218,7 @@ func (n *netUnix) ReadSeqFileData(ctx context.Context, h seqfile.SeqHandle) ([]s
}
sfile := s.(*fs.File)
if family, _, _ := sfile.FileOperations.(socket.Socket).Type(); family != linux.AF_UNIX {
+ s.DecRef()
// Not a unix socket.
continue
}
@@ -281,12 +278,160 @@ func (n *netUnix) ReadSeqFileData(ctx context.Context, h seqfile.SeqHandle) ([]s
}
fmt.Fprintf(&buf, "\n")
- sfile.DecRef()
+ s.DecRef()
+ }
+
+ data := []seqfile.SeqData{
+ {
+ Buf: []byte("Num RefCount Protocol Flags Type St Inode Path\n"),
+ Handle: n,
+ },
+ {
+ Buf: buf.Bytes(),
+ Handle: n,
+ },
+ }
+ return data, 0
+}
+
+// netTCP implements seqfile.SeqSource for /proc/net/tcp.
+//
+// +stateify savable
+type netTCP struct {
+ k *kernel.Kernel
+}
+
+// NeedsUpdate implements seqfile.SeqSource.NeedsUpdate.
+func (*netTCP) NeedsUpdate(generation int64) bool {
+ return true
+}
+
+// ReadSeqFileData implements seqfile.SeqSource.ReadSeqFileData.
+func (n *netTCP) ReadSeqFileData(ctx context.Context, h seqfile.SeqHandle) ([]seqfile.SeqData, int64) {
+ t := kernel.TaskFromContext(ctx)
+
+ if h != nil {
+ return nil, 0
+ }
+
+ var buf bytes.Buffer
+ for _, se := range n.k.ListSockets() {
+ s := se.Sock.Get()
+ if s == nil {
+ log.Debugf("Couldn't resolve weakref %+v in socket table, racing with destruction?", se.Sock)
+ continue
+ }
+ sfile := s.(*fs.File)
+ sops, ok := sfile.FileOperations.(socket.Socket)
+ if !ok {
+ panic(fmt.Sprintf("Found non-socket file in socket table: %+v", sfile))
+ }
+ if family, stype, _ := sops.Type(); !(family == linux.AF_INET && stype == linux.SOCK_STREAM) {
+ s.DecRef()
+ // Not tcp4 sockets.
+ continue
+ }
+
+ // Linux's documentation for the fields below can be found at
+ // https://www.kernel.org/doc/Documentation/networking/proc_net_tcp.txt.
+ // For Linux's implementation, see net/ipv4/tcp_ipv4.c:get_tcp4_sock().
+ // Note that the header doesn't contain labels for all the fields.
+
+ // Field: sl; entry number.
+ fmt.Fprintf(&buf, "%4d: ", se.ID)
+
+ portBuf := make([]byte, 2)
+
+ // Field: local_adddress.
+ var localAddr linux.SockAddrInet
+ if local, _, err := sops.GetSockName(t); err == nil {
+ localAddr = local.(linux.SockAddrInet)
+ }
+ binary.LittleEndian.PutUint16(portBuf, localAddr.Port)
+ fmt.Fprintf(&buf, "%08X:%04X ",
+ binary.LittleEndian.Uint32(localAddr.Addr[:]),
+ portBuf)
+
+ // Field: rem_address.
+ var remoteAddr linux.SockAddrInet
+ if remote, _, err := sops.GetPeerName(t); err == nil {
+ remoteAddr = remote.(linux.SockAddrInet)
+ }
+ binary.LittleEndian.PutUint16(portBuf, remoteAddr.Port)
+ fmt.Fprintf(&buf, "%08X:%04X ",
+ binary.LittleEndian.Uint32(remoteAddr.Addr[:]),
+ portBuf)
+
+ // Field: state; socket state.
+ fmt.Fprintf(&buf, "%02X ", sops.State())
+
+ // Field: tx_queue, rx_queue; number of packets in the transmit and
+ // receive queue. Unimplemented.
+ fmt.Fprintf(&buf, "%08X:%08X ", 0, 0)
+
+ // Field: tr, tm->when; timer active state and number of jiffies
+ // until timer expires. Unimplemented.
+ fmt.Fprintf(&buf, "%02X:%08X ", 0, 0)
+
+ // Field: retrnsmt; number of unrecovered RTO timeouts.
+ // Unimplemented.
+ fmt.Fprintf(&buf, "%08X ", 0)
+
+ // Field: uid.
+ uattr, err := sfile.Dirent.Inode.UnstableAttr(ctx)
+ if err != nil {
+ log.Warningf("Failed to retrieve unstable attr for socket file: %v", err)
+ fmt.Fprintf(&buf, "%5d ", 0)
+ } else {
+ fmt.Fprintf(&buf, "%5d ", uint32(uattr.Owner.UID.In(t.UserNamespace()).OrOverflow()))
+ }
+
+ // Field: timeout; number of unanswered 0-window probes.
+ // Unimplemented.
+ fmt.Fprintf(&buf, "%8d ", 0)
+
+ // Field: inode.
+ fmt.Fprintf(&buf, "%8d ", sfile.InodeID())
+
+ // Field: refcount. Don't count the ref we obtain while deferencing
+ // the weakref to this socket.
+ fmt.Fprintf(&buf, "%d ", sfile.ReadRefs()-1)
+
+ // Field: Socket struct address. Redacted due to the same reason as
+ // the 'Num' field in /proc/net/unix, see netUnix.ReadSeqFileData.
+ fmt.Fprintf(&buf, "%#016p ", (*socket.Socket)(nil))
+
+ // Field: retransmit timeout. Unimplemented.
+ fmt.Fprintf(&buf, "%d ", 0)
+
+ // Field: predicted tick of soft clock (delayed ACK control data).
+ // Unimplemented.
+ fmt.Fprintf(&buf, "%d ", 0)
+
+ // Field: (ack.quick<<1)|ack.pingpong, Unimplemented.
+ fmt.Fprintf(&buf, "%d ", 0)
+
+ // Field: sending congestion window, Unimplemented.
+ fmt.Fprintf(&buf, "%d ", 0)
+
+ // Field: Slow start size threshold, -1 if threshold >= 0xFFFF.
+ // Unimplemented, report as large threshold.
+ fmt.Fprintf(&buf, "%d", -1)
+
+ fmt.Fprintf(&buf, "\n")
+
+ s.DecRef()
}
- data := []seqfile.SeqData{{
- Buf: buf.Bytes(),
- Handle: (*netUnix)(nil),
- }}
+ data := []seqfile.SeqData{
+ {
+ Buf: []byte(" sl local_address rem_address st tx_queue rx_queue tr tm->when retrnsmt uid timeout inode \n"),
+ Handle: n,
+ },
+ {
+ Buf: buf.Bytes(),
+ Handle: n,
+ },
+ }
return data, 0
}
diff --git a/test/syscalls/linux/BUILD b/test/syscalls/linux/BUILD
index 0618fea58..bfe3dfe04 100644
--- a/test/syscalls/linux/BUILD
+++ b/test/syscalls/linux/BUILD
@@ -3340,3 +3340,18 @@ cc_binary(
"@com_google_googletest//:gtest",
],
)
+
+cc_binary(
+ name = "proc_net_tcp_test",
+ testonly = 1,
+ srcs = ["proc_net_tcp.cc"],
+ linkstatic = 1,
+ deps = [
+ ":ip_socket_test_util",
+ "//test/util:file_descriptor",
+ "//test/util:test_main",
+ "//test/util:test_util",
+ "@com_google_absl//absl/strings",
+ "@com_google_googletest//:gtest",
+ ],
+)
diff --git a/test/syscalls/linux/proc_net_tcp.cc b/test/syscalls/linux/proc_net_tcp.cc
new file mode 100644
index 000000000..578b20680
--- /dev/null
+++ b/test/syscalls/linux/proc_net_tcp.cc
@@ -0,0 +1,281 @@
+// Copyright 2019 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include <sys/socket.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include "gtest/gtest.h"
+#include "gtest/gtest.h"
+#include "absl/strings/numbers.h"
+#include "absl/strings/str_join.h"
+#include "absl/strings/str_split.h"
+#include "test/syscalls/linux/ip_socket_test_util.h"
+#include "test/util/file_descriptor.h"
+#include "test/util/test_util.h"
+
+namespace gvisor {
+namespace testing {
+namespace {
+
+using absl::StrCat;
+using absl::StrSplit;
+
+constexpr char kProcNetTCPHeader[] =
+ " sl local_address rem_address st tx_queue rx_queue tr tm->when "
+ "retrnsmt uid timeout inode "
+ " ";
+
+// Possible values of the "st" field in a /proc/net/tcp entry. Source: Linux
+// kernel, include/net/tcp_states.h.
+enum {
+ TCP_ESTABLISHED = 1,
+ TCP_SYN_SENT,
+ TCP_SYN_RECV,
+ TCP_FIN_WAIT1,
+ TCP_FIN_WAIT2,
+ TCP_TIME_WAIT,
+ TCP_CLOSE,
+ TCP_CLOSE_WAIT,
+ TCP_LAST_ACK,
+ TCP_LISTEN,
+ TCP_CLOSING,
+ TCP_NEW_SYN_RECV,
+
+ TCP_MAX_STATES
+};
+
+// TCPEntry represents a single entry from /proc/net/tcp.
+struct TCPEntry {
+ uint32_t local_addr;
+ uint16_t local_port;
+
+ uint32_t remote_addr;
+ uint16_t remote_port;
+
+ uint64_t state;
+ uint64_t uid;
+ uint64_t inode;
+};
+
+uint32_t IP(const struct sockaddr* addr) {
+ auto* in_addr = reinterpret_cast<const struct sockaddr_in*>(addr);
+ return in_addr->sin_addr.s_addr;
+}
+
+uint16_t Port(const struct sockaddr* addr) {
+ auto* in_addr = reinterpret_cast<const struct sockaddr_in*>(addr);
+ return ntohs(in_addr->sin_port);
+}
+
+// Finds the first entry in 'entries' for which 'predicate' returns true.
+// Returns true on match, and sets 'match' to point to the matching entry.
+bool FindBy(std::vector<TCPEntry> entries, TCPEntry* match,
+ std::function<bool(const TCPEntry&)> predicate) {
+ for (int i = 0; i < entries.size(); ++i) {
+ if (predicate(entries[i])) {
+ *match = entries[i];
+ return true;
+ }
+ }
+ return false;
+}
+
+bool FindByLocalAddr(std::vector<TCPEntry> entries, TCPEntry* match,
+ const struct sockaddr* addr) {
+ uint32_t host = IP(addr);
+ uint16_t port = Port(addr);
+ return FindBy(entries, match, [host, port](const TCPEntry& e) {
+ return (e.local_addr == host && e.local_port == port);
+ });
+}
+
+bool FindByRemoteAddr(std::vector<TCPEntry> entries, TCPEntry* match,
+ const struct sockaddr* addr) {
+ uint32_t host = IP(addr);
+ uint16_t port = Port(addr);
+ return FindBy(entries, match, [host, port](const TCPEntry& e) {
+ return (e.remote_addr == host && e.remote_port == port);
+ });
+}
+
+// Returns a parsed representation of /proc/net/tcp entries.
+PosixErrorOr<std::vector<TCPEntry>> ProcNetTCPEntries() {
+ std::string content;
+ RETURN_IF_ERRNO(GetContents("/proc/net/tcp", &content));
+
+ bool found_header = false;
+ std::vector<TCPEntry> entries;
+ std::vector<std::string> lines = StrSplit(content, '\n');
+ std::cerr << "<contents of /proc/net/tcp>" << std::endl;
+ for (std::string line : lines) {
+ std::cerr << line << std::endl;
+
+ if (!found_header) {
+ EXPECT_EQ(line, kProcNetTCPHeader);
+ found_header = true;
+ continue;
+ }
+ if (line.empty()) {
+ continue;
+ }
+
+ // Parse a single entry from /proc/net/tcp.
+ //
+ // Example entries:
+ //
+ // clang-format off
+ //
+ // sl local_address rem_address st tx_queue rx_queue tr tm->when retrnsmt uid timeout inode
+ // 0: 00000000:006F 00000000:0000 0A 00000000:00000000 00:00000000 00000000 0 0 1968 1 0000000000000000 100 0 0 10 0
+ // 1: 0100007F:7533 00000000:0000 0A 00000000:00000000 00:00000000 00000000 120 0 10684 1 0000000000000000 100 0 0 10 0
+ // ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^
+ // 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
+ //
+ // clang-format on
+
+ TCPEntry entry;
+ std::vector<std::string> fields =
+ StrSplit(line, absl::ByAnyChar(": "), absl::SkipEmpty());
+
+ ASSIGN_OR_RETURN_ERRNO(entry.local_addr, AtoiBase(fields[1], 16));
+ ASSIGN_OR_RETURN_ERRNO(entry.local_port, AtoiBase(fields[2], 16));
+
+ ASSIGN_OR_RETURN_ERRNO(entry.remote_addr, AtoiBase(fields[3], 16));
+ ASSIGN_OR_RETURN_ERRNO(entry.remote_port, AtoiBase(fields[4], 16));
+
+ ASSIGN_OR_RETURN_ERRNO(entry.state, AtoiBase(fields[5], 16));
+ ASSIGN_OR_RETURN_ERRNO(entry.uid, Atoi<uint64_t>(fields[11]));
+ ASSIGN_OR_RETURN_ERRNO(entry.inode, Atoi<uint64_t>(fields[13]));
+
+ entries.push_back(entry);
+ }
+ std::cerr << "<end of /proc/net/tcp>" << std::endl;
+
+ return entries;
+}
+
+TEST(ProcNetTCP, Exists) {
+ const std::string content =
+ ASSERT_NO_ERRNO_AND_VALUE(GetContents("/proc/net/tcp"));
+ const std::string header_line = StrCat(kProcNetTCPHeader, "\n");
+ if (IsRunningOnGvisor()) {
+ // Should be just the header since we don't have any tcp sockets yet.
+ EXPECT_EQ(content, header_line);
+ } else {
+ // On a general linux machine, we could have abitrary sockets on the system,
+ // so just check the header.
+ EXPECT_THAT(content, ::testing::StartsWith(header_line));
+ }
+}
+
+TEST(ProcNetTCP, EntryUID) {
+ auto sockets =
+ ASSERT_NO_ERRNO_AND_VALUE(IPv4TCPAcceptBindSocketPair(0).Create());
+ std::vector<TCPEntry> entries =
+ ASSERT_NO_ERRNO_AND_VALUE(ProcNetTCPEntries());
+ TCPEntry e;
+ EXPECT_TRUE(FindByLocalAddr(entries, &e, sockets->first_addr()));
+ EXPECT_EQ(e.uid, geteuid());
+ EXPECT_TRUE(FindByRemoteAddr(entries, &e, sockets->first_addr()));
+ EXPECT_EQ(e.uid, geteuid());
+}
+
+TEST(ProcNetTCP, BindAcceptConnect) {
+ auto sockets =
+ ASSERT_NO_ERRNO_AND_VALUE(IPv4TCPAcceptBindSocketPair(0).Create());
+ std::vector<TCPEntry> entries =
+ ASSERT_NO_ERRNO_AND_VALUE(ProcNetTCPEntries());
+ // We can only make assertions about the total number of entries if we control
+ // the entire "machine".
+ if (IsRunningOnGvisor()) {
+ EXPECT_EQ(entries.size(), 2);
+ }
+
+ TCPEntry e;
+ EXPECT_TRUE(FindByLocalAddr(entries, &e, sockets->first_addr()));
+ EXPECT_TRUE(FindByRemoteAddr(entries, &e, sockets->first_addr()));
+}
+
+TEST(ProcNetTCP, InodeReasonable) {
+ auto sockets =
+ ASSERT_NO_ERRNO_AND_VALUE(IPv4TCPAcceptBindSocketPair(0).Create());
+ std::vector<TCPEntry> entries =
+ ASSERT_NO_ERRNO_AND_VALUE(ProcNetTCPEntries());
+
+ TCPEntry accepted_entry;
+ ASSERT_TRUE(FindByLocalAddr(entries, &accepted_entry, sockets->first_addr()));
+ EXPECT_NE(accepted_entry.inode, 0);
+
+ TCPEntry client_entry;
+ ASSERT_TRUE(FindByRemoteAddr(entries, &client_entry, sockets->first_addr()));
+ EXPECT_NE(client_entry.inode, 0);
+ EXPECT_NE(accepted_entry.inode, client_entry.inode);
+}
+
+TEST(ProcNetTCP, State) {
+ std::unique_ptr<FileDescriptor> server =
+ ASSERT_NO_ERRNO_AND_VALUE(IPv4TCPUnboundSocket(0).Create());
+
+ auto test_addr = V4Loopback();
+ ASSERT_THAT(
+ bind(server->get(), reinterpret_cast<struct sockaddr*>(&test_addr.addr),
+ test_addr.addr_len),
+ SyscallSucceeds());
+
+ struct sockaddr addr;
+ socklen_t addrlen = sizeof(struct sockaddr);
+ ASSERT_THAT(getsockname(server->get(), &addr, &addrlen), SyscallSucceeds());
+ ASSERT_EQ(addrlen, sizeof(struct sockaddr));
+
+ ASSERT_THAT(listen(server->get(), 10), SyscallSucceeds());
+ std::vector<TCPEntry> entries =
+ ASSERT_NO_ERRNO_AND_VALUE(ProcNetTCPEntries());
+ TCPEntry listen_entry;
+ ASSERT_TRUE(FindByLocalAddr(entries, &listen_entry, &addr));
+ EXPECT_EQ(listen_entry.state, TCP_LISTEN);
+
+ std::unique_ptr<FileDescriptor> client =
+ ASSERT_NO_ERRNO_AND_VALUE(IPv4TCPUnboundSocket(0).Create());
+ ASSERT_THAT(connect(client->get(), &addr, addrlen), SyscallSucceeds());
+ entries = ASSERT_NO_ERRNO_AND_VALUE(ProcNetTCPEntries());
+ ASSERT_TRUE(FindByLocalAddr(entries, &listen_entry, &addr));
+ EXPECT_EQ(listen_entry.state, TCP_LISTEN);
+ TCPEntry client_entry;
+ ASSERT_TRUE(FindByRemoteAddr(entries, &client_entry, &addr));
+ EXPECT_EQ(client_entry.state, TCP_ESTABLISHED);
+
+ FileDescriptor accepted =
+ ASSERT_NO_ERRNO_AND_VALUE(Accept(server->get(), nullptr, nullptr));
+
+ const uint32_t accepted_local_host = IP(&addr);
+ const uint16_t accepted_local_port = Port(&addr);
+
+ entries = ASSERT_NO_ERRNO_AND_VALUE(ProcNetTCPEntries());
+ TCPEntry accepted_entry;
+ ASSERT_TRUE(FindBy(entries, &accepted_entry,
+ [client_entry, accepted_local_host,
+ accepted_local_port](const TCPEntry& e) {
+ return e.local_addr == accepted_local_host &&
+ e.local_port == accepted_local_port &&
+ e.remote_addr == client_entry.local_addr &&
+ e.remote_port == client_entry.local_port;
+ }));
+ EXPECT_EQ(accepted_entry.state, TCP_ESTABLISHED);
+}
+
+} // namespace
+} // namespace testing
+} // namespace gvisor
diff --git a/test/syscalls/linux/proc_net_unix.cc b/test/syscalls/linux/proc_net_unix.cc
index 82d325c17..74acbe92c 100644
--- a/test/syscalls/linux/proc_net_unix.cc
+++ b/test/syscalls/linux/proc_net_unix.cc
@@ -162,7 +162,7 @@ PosixErrorOr<std::vector<UnixEntry>> ProcNetUnixEntries() {
// Finds the first entry in 'entries' for which 'predicate' returns true.
// Returns true on match, and sets 'match' to point to the matching entry.
bool FindBy(std::vector<UnixEntry> entries, UnixEntry* match,
- std::function<bool(UnixEntry)> predicate) {
+ std::function<bool(const UnixEntry&)> predicate) {
for (int i = 0; i < entries.size(); ++i) {
if (predicate(entries[i])) {
*match = entries[i];
@@ -174,7 +174,8 @@ bool FindBy(std::vector<UnixEntry> entries, UnixEntry* match,
bool FindByPath(std::vector<UnixEntry> entries, UnixEntry* match,
const std::string& path) {
- return FindBy(entries, match, [path](UnixEntry e) { return e.path == path; });
+ return FindBy(entries, match,
+ [path](const UnixEntry& e) { return e.path == path; });
}
TEST(ProcNetUnix, Exists) {