From e3d4a6773923a884986aaa4bb272431ce27764e2 Mon Sep 17 00:00:00 2001 From: Jianfeng Tan Date: Tue, 2 Apr 2019 17:13:00 +0800 Subject: support /proc/net/snmp This proc file contains statistics according to [1]. [1] https://tools.ietf.org/html/rfc2013 Signed-off-by: Jianfeng Tan Change-Id: I9662132085edd8a7783d356ce4237d7ac0800d94 --- pkg/sentry/fs/proc/net.go | 117 +++++++++++++++++++++- pkg/sentry/inet/inet.go | 20 ++++ test/syscalls/linux/BUILD | 1 + test/syscalls/linux/proc_net.cc | 213 +++++++++++++++++++++++++++++++++++++++- 4 files changed, 349 insertions(+), 2 deletions(-) diff --git a/pkg/sentry/fs/proc/net.go b/pkg/sentry/fs/proc/net.go index f70239449..ec1bc1d17 100644 --- a/pkg/sentry/fs/proc/net.go +++ b/pkg/sentry/fs/proc/net.go @@ -18,6 +18,7 @@ import ( "bytes" "fmt" "io" + "reflect" "time" "gvisor.dev/gvisor/pkg/abi/linux" @@ -33,6 +34,7 @@ import ( "gvisor.dev/gvisor/pkg/sentry/socket/unix" "gvisor.dev/gvisor/pkg/sentry/socket/unix/transport" "gvisor.dev/gvisor/pkg/sentry/usermem" + "gvisor.dev/gvisor/pkg/syserror" ) // newNet creates a new proc net entry. @@ -40,7 +42,8 @@ func (p *proc) newNetDir(ctx context.Context, k *kernel.Kernel, msrc *fs.MountSo var contents map[string]*fs.Inode if s := p.k.NetworkStack(); s != nil { contents = map[string]*fs.Inode{ - "dev": seqfile.NewSeqFileInode(ctx, &netDev{s: s}, msrc), + "dev": seqfile.NewSeqFileInode(ctx, &netDev{s: s}, msrc), + "snmp": seqfile.NewSeqFileInode(ctx, &netSnmp{s: s}, msrc), // The following files are simple stubs until they are // implemented in netstack, if the file contains a @@ -195,6 +198,118 @@ func (n *netDev) ReadSeqFileData(ctx context.Context, h seqfile.SeqHandle) ([]se return data, 0 } +// netSnmp implements seqfile.SeqSource for /proc/net/snmp. +// +// +stateify savable +type netSnmp struct { + s inet.Stack +} + +// NeedsUpdate implements seqfile.SeqSource.NeedsUpdate. +func (n *netSnmp) NeedsUpdate(generation int64) bool { + return true +} + +type snmpLine struct { + prefix string + header string +} + +var snmp = []snmpLine{ + { + prefix: "Ip", + header: "Forwarding DefaultTTL InReceives InHdrErrors InAddrErrors ForwDatagrams InUnknownProtos InDiscards InDelivers OutRequests OutDiscards OutNoRoutes ReasmTimeout ReasmReqds ReasmOKs ReasmFails FragOKs FragFails FragCreates", + }, + { + prefix: "Icmp", + header: "InMsgs InErrors InCsumErrors InDestUnreachs InTimeExcds InParmProbs InSrcQuenchs InRedirects InEchos InEchoReps InTimestamps InTimestampReps InAddrMasks InAddrMaskReps OutMsgs OutErrors OutDestUnreachs OutTimeExcds OutParmProbs OutSrcQuenchs OutRedirects OutEchos OutEchoReps OutTimestamps OutTimestampReps OutAddrMasks OutAddrMaskReps", + }, + { + prefix: "IcmpMsg", + }, + { + prefix: "Tcp", + header: "RtoAlgorithm RtoMin RtoMax MaxConn ActiveOpens PassiveOpens AttemptFails EstabResets CurrEstab InSegs OutSegs RetransSegs InErrs OutRsts InCsumErrors", + }, + { + prefix: "Udp", + header: "InDatagrams NoPorts InErrors OutDatagrams RcvbufErrors SndbufErrors InCsumErrors IgnoredMulti", + }, + { + prefix: "UdpLite", + header: "InDatagrams NoPorts InErrors OutDatagrams RcvbufErrors SndbufErrors InCsumErrors IgnoredMulti", + }, +} + +func toSlice(a interface{}) []uint64 { + v := reflect.Indirect(reflect.ValueOf(a)) + return v.Slice(0, v.Len()).Interface().([]uint64) +} + +func sprintSlice(s []uint64) string { + if len(s) == 0 { + return "" + } + r := fmt.Sprint(s) + return r[1 : len(r)-1] // Remove "[]" introduced by fmt of slice. +} + +// ReadSeqFileData implements seqfile.SeqSource.ReadSeqFileData. See Linux's +// net/core/net-procfs.c:dev_seq_show. +func (n *netSnmp) ReadSeqFileData(ctx context.Context, h seqfile.SeqHandle) ([]seqfile.SeqData, int64) { + if h != nil { + return nil, 0 + } + + contents := make([]string, 0, len(snmp)*2) + types := []interface{}{ + &inet.StatSNMPIP{}, + &inet.StatSNMPICMP{}, + nil, // TODO(gvisor.dev/issue/628): Support IcmpMsg stats. + &inet.StatSNMPTCP{}, + &inet.StatSNMPUDP{}, + &inet.StatSNMPUDPLite{}, + } + for i, stat := range types { + line := snmp[i] + if stat == nil { + contents = append( + contents, + fmt.Sprintf("%s:\n", line.prefix), + fmt.Sprintf("%s:\n", line.prefix), + ) + continue + } + if err := n.s.Statistics(stat, line.prefix); err != nil { + if err == syserror.EOPNOTSUPP { + log.Infof("Failed to retrieve %s of /proc/net/snmp: %v", line.prefix, err) + } else { + log.Warningf("Failed to retrieve %s of /proc/net/snmp: %v", line.prefix, err) + } + } + var values string + if line.prefix == "Tcp" { + tcp := stat.(*inet.StatSNMPTCP) + // "Tcp" needs special processing because MaxConn is signed. RFC 2012. + values = fmt.Sprintf("%s %d %s", sprintSlice(tcp[:3]), int64(tcp[3]), sprintSlice(tcp[4:])) + } else { + values = sprintSlice(toSlice(stat)) + } + contents = append( + contents, + fmt.Sprintf("%s: %s\n", line.prefix, line.header), + fmt.Sprintf("%s: %s\n", line.prefix, values), + ) + } + + data := make([]seqfile.SeqData, 0, len(snmp)*2) + for _, l := range contents { + data = append(data, seqfile.SeqData{Buf: []byte(l), Handle: (*netSnmp)(nil)}) + } + + return data, 0 +} + // netUnix implements seqfile.SeqSource for /proc/net/unix. // // +stateify savable diff --git a/pkg/sentry/inet/inet.go b/pkg/sentry/inet/inet.go index 80f227dbe..bc6cb1095 100644 --- a/pkg/sentry/inet/inet.go +++ b/pkg/sentry/inet/inet.go @@ -153,3 +153,23 @@ type Route struct { // GatewayAddr is the route gateway address (RTA_GATEWAY). GatewayAddr []byte } + +// Below SNMP metrics are from Linux/usr/include/linux/snmp.h. + +// StatSNMPIP describes Ip line of /proc/net/snmp. +type StatSNMPIP [19]uint64 + +// StatSNMPICMP describes Icmp line of /proc/net/snmp. +type StatSNMPICMP [27]uint64 + +// StatSNMPICMPMSG describes IcmpMsg line of /proc/net/snmp. +type StatSNMPICMPMSG [512]uint64 + +// StatSNMPTCP describes Tcp line of /proc/net/snmp. +type StatSNMPTCP [15]uint64 + +// StatSNMPUDP describes Udp line of /proc/net/snmp. +type StatSNMPUDP [8]uint64 + +// StatSNMPUDPLite describes UdpLite line of /proc/net/snmp. +type StatSNMPUDPLite [8]uint64 diff --git a/test/syscalls/linux/BUILD b/test/syscalls/linux/BUILD index 84a8eb76c..d243be9e4 100644 --- a/test/syscalls/linux/BUILD +++ b/test/syscalls/linux/BUILD @@ -1552,6 +1552,7 @@ cc_binary( srcs = ["proc_net.cc"], linkstatic = 1, deps = [ + ":socket_test_util", "//test/util:capability_util", "//test/util:file_descriptor", "//test/util:fs_util", diff --git a/test/syscalls/linux/proc_net.cc b/test/syscalls/linux/proc_net.cc index efdaf202b..af4cd616a 100644 --- a/test/syscalls/linux/proc_net.cc +++ b/test/syscalls/linux/proc_net.cc @@ -12,9 +12,17 @@ // See the License for the specific language governing permissions and // limitations under the License. -#include "gtest/gtest.h" +#include +#include +#include +#include +#include +#include + +#include "absl/strings/str_split.h" #include "gtest/gtest.h" #include "test/util/capability_util.h" +#include "test/syscalls/linux/socket_test_util.h" #include "test/util/file_descriptor.h" #include "test/util/fs_util.h" #include "test/util/test_util.h" @@ -57,6 +65,209 @@ TEST(ProcSysNetIpv4Sack, CanReadAndWrite) { EXPECT_EQ(buf, to_write); } +PosixErrorOr GetSNMPMetricFromProc(const std::string snmp, + const std::string &type, + const std::string &item) { + std::vector snmp_vec = absl::StrSplit(snmp, '\n'); + + // /proc/net/snmp prints a line of headers followed by a line of metrics. + // Only search the headers. + for (unsigned i = 0; i < snmp_vec.size(); i = i + 2) { + if (!absl::StartsWith(snmp_vec[i], type)) continue; + + std::vector fields = + absl::StrSplit(snmp_vec[i], ' ', absl::SkipWhitespace()); + + EXPECT_TRUE((i + 1) < snmp_vec.size()); + std::vector values = + absl::StrSplit(snmp_vec[i + 1], ' ', absl::SkipWhitespace()); + + EXPECT_TRUE(!fields.empty() && fields.size() == values.size()); + + // Metrics start at the first index. + for (unsigned j = 1; j < fields.size(); j++) { + if (fields[j] == item) { + uint64_t val; + if (!absl::SimpleAtoi(values[j], &val)) { + return PosixError(EINVAL, + absl::StrCat("field is not a number: ", values[j])); + } + + return val; + } + } + } + // We should never get here. + return PosixError( + EINVAL, absl::StrCat("failed to find ", type, "/", item, " in:", snmp)); +} + +TEST(ProcNetSnmp, TcpReset) { + // TODO(gvisor.dev/issue/866): epsocket metrics are not savable. + const DisableSave ds; + + uint64_t oldAttemptFails; + uint64_t oldActiveOpens; + uint64_t oldOutRsts; + auto snmp = ASSERT_NO_ERRNO_AND_VALUE(GetContents("/proc/net/snmp")); + oldActiveOpens = ASSERT_NO_ERRNO_AND_VALUE(GetSNMPMetricFromProc(snmp, "Tcp", "ActiveOpens")); + oldOutRsts = ASSERT_NO_ERRNO_AND_VALUE(GetSNMPMetricFromProc(snmp, "Tcp", "OutRsts")); + oldAttemptFails = ASSERT_NO_ERRNO_AND_VALUE(GetSNMPMetricFromProc(snmp, "Tcp", "AttemptFails")); + + FileDescriptor s = ASSERT_NO_ERRNO_AND_VALUE(Socket(AF_INET, SOCK_STREAM, 0)); + + struct sockaddr_in sin = { + .sin_family = AF_INET, + .sin_port = htons(1234), + }; + sin.sin_addr.s_addr = inet_addr("127.0.0.1"); + ASSERT_THAT(connect(s.get(), (struct sockaddr *)&sin, sizeof(sin)), + SyscallFailsWithErrno(ECONNREFUSED)); + + uint64_t newAttemptFails; + uint64_t newActiveOpens; + uint64_t newOutRsts; + snmp = ASSERT_NO_ERRNO_AND_VALUE(GetContents("/proc/net/snmp")); + newActiveOpens = ASSERT_NO_ERRNO_AND_VALUE(GetSNMPMetricFromProc(snmp, "Tcp", "ActiveOpens")); + newOutRsts = ASSERT_NO_ERRNO_AND_VALUE(GetSNMPMetricFromProc(snmp, "Tcp", "OutRsts")); + newAttemptFails = ASSERT_NO_ERRNO_AND_VALUE(GetSNMPMetricFromProc(snmp, "Tcp", "AttemptFails")); + + EXPECT_EQ(oldActiveOpens, newActiveOpens - 1); + EXPECT_EQ(oldOutRsts, newOutRsts - 1); + EXPECT_EQ(oldAttemptFails, newAttemptFails - 1); +} + +TEST(ProcNetSnmp, TcpEstab) { + // TODO(gvisor.dev/issue/866): epsocket metrics are not savable. + const DisableSave ds; + + uint64_t oldEstabResets; + uint64_t oldActiveOpens; + uint64_t oldPassiveOpens; + uint64_t oldCurrEstab; + auto snmp = ASSERT_NO_ERRNO_AND_VALUE(GetContents("/proc/net/snmp")); + oldActiveOpens = ASSERT_NO_ERRNO_AND_VALUE(GetSNMPMetricFromProc(snmp, "Tcp", "ActiveOpens")); + oldPassiveOpens = ASSERT_NO_ERRNO_AND_VALUE(GetSNMPMetricFromProc(snmp, "Tcp", "PassiveOpens")); + oldCurrEstab = ASSERT_NO_ERRNO_AND_VALUE(GetSNMPMetricFromProc(snmp, "Tcp", "CurrEstab")); + oldEstabResets = ASSERT_NO_ERRNO_AND_VALUE(GetSNMPMetricFromProc(snmp, "Tcp", "EstabResets")); + + FileDescriptor s_listen = + ASSERT_NO_ERRNO_AND_VALUE(Socket(AF_INET, SOCK_STREAM, 0)); + + struct sockaddr_in sin = { + .sin_family = AF_INET, + .sin_port = htons(1234), + }; + sin.sin_addr.s_addr = inet_addr("127.0.0.1"); + ASSERT_THAT(bind(s_listen.get(), (struct sockaddr *)&sin, sizeof(sin)), + SyscallSucceeds()); + ASSERT_THAT(listen(s_listen.get(), 1), SyscallSucceeds()); + + FileDescriptor s_connect = + ASSERT_NO_ERRNO_AND_VALUE(Socket(AF_INET, SOCK_STREAM, 0)); + ASSERT_THAT(connect(s_connect.get(), (struct sockaddr *)&sin, sizeof(sin)), + SyscallSucceeds()); + + auto s_accept = + ASSERT_NO_ERRNO_AND_VALUE(Accept(s_listen.get(), nullptr, nullptr)); + + uint64_t newEstabResets; + uint64_t newActiveOpens; + uint64_t newPassiveOpens; + uint64_t newCurrEstab; + snmp = ASSERT_NO_ERRNO_AND_VALUE(GetContents("/proc/net/snmp")); + newActiveOpens = ASSERT_NO_ERRNO_AND_VALUE(GetSNMPMetricFromProc(snmp, "Tcp", "ActiveOpens")); + newPassiveOpens = ASSERT_NO_ERRNO_AND_VALUE(GetSNMPMetricFromProc(snmp, "Tcp", "PassiveOpens")); + newCurrEstab = ASSERT_NO_ERRNO_AND_VALUE(GetSNMPMetricFromProc(snmp, "Tcp", "CurrEstab")); + + EXPECT_EQ(oldActiveOpens, newActiveOpens - 1); + EXPECT_EQ(oldPassiveOpens, newPassiveOpens - 1); + EXPECT_EQ(oldCurrEstab, newCurrEstab - 2); + + ASSERT_THAT(send(s_connect.get(), "a", 1, 0), SyscallSucceedsWithValue(1)); + + s_accept.reset(-1); + s_connect.reset(-1); + + snmp = ASSERT_NO_ERRNO_AND_VALUE(GetContents("/proc/net/snmp")); + newCurrEstab = ASSERT_NO_ERRNO_AND_VALUE(GetSNMPMetricFromProc(snmp, "Tcp", "CurrEstab")); + newEstabResets = ASSERT_NO_ERRNO_AND_VALUE(GetSNMPMetricFromProc(snmp, "Tcp", "EstabResets")); + + EXPECT_EQ(oldCurrEstab, newCurrEstab); + EXPECT_EQ(oldEstabResets, newEstabResets - 2); +} + +TEST(ProcNetSnmp, UdpNoPorts) { + // TODO(gvisor.dev/issue/866): epsocket metrics are not savable. + const DisableSave ds; + + uint64_t oldOutDatagrams; + uint64_t oldNoPorts; + auto snmp = ASSERT_NO_ERRNO_AND_VALUE(GetContents("/proc/net/snmp")); + oldOutDatagrams = ASSERT_NO_ERRNO_AND_VALUE(GetSNMPMetricFromProc(snmp, "Udp", "OutDatagrams")); + oldNoPorts = ASSERT_NO_ERRNO_AND_VALUE(GetSNMPMetricFromProc(snmp, "Udp", "NoPorts")); + + FileDescriptor s = + ASSERT_NO_ERRNO_AND_VALUE(Socket(AF_INET, SOCK_DGRAM, 0)); + + struct sockaddr_in sin = { + .sin_family = AF_INET, + .sin_port = htons(1234), + }; + sin.sin_addr.s_addr = inet_addr("127.0.0.1"); + ASSERT_THAT(sendto(s.get(), "a", 1, 0, (struct sockaddr *)&sin, sizeof(sin)), + SyscallSucceedsWithValue(1)); + + uint64_t newOutDatagrams; + uint64_t newNoPorts; + snmp = ASSERT_NO_ERRNO_AND_VALUE(GetContents("/proc/net/snmp")); + newOutDatagrams = ASSERT_NO_ERRNO_AND_VALUE(GetSNMPMetricFromProc(snmp, "Udp", "OutDatagrams")); + newNoPorts = ASSERT_NO_ERRNO_AND_VALUE(GetSNMPMetricFromProc(snmp, "Udp", "NoPorts")); + + EXPECT_EQ(oldOutDatagrams, newOutDatagrams - 1); + EXPECT_EQ(oldNoPorts, newNoPorts - 1); +} + +TEST(ProcNetSnmp, UdpIn) { + // TODO(gvisor.dev/issue/866): epsocket metrics are not savable. + const DisableSave ds; + + uint64_t oldOutDatagrams; + uint64_t oldInDatagrams; + auto snmp = ASSERT_NO_ERRNO_AND_VALUE(GetContents("/proc/net/snmp")); + oldOutDatagrams = ASSERT_NO_ERRNO_AND_VALUE(GetSNMPMetricFromProc(snmp, "Udp", "OutDatagrams")); + oldInDatagrams = ASSERT_NO_ERRNO_AND_VALUE(GetSNMPMetricFromProc(snmp, "Udp", "InDatagrams")); + + FileDescriptor server = + ASSERT_NO_ERRNO_AND_VALUE(Socket(AF_INET, SOCK_DGRAM, 0)); + + struct sockaddr_in sin = { + .sin_family = AF_INET, + .sin_port = htons(1234), + }; + sin.sin_addr.s_addr = inet_addr("127.0.0.1"); + ASSERT_THAT(bind(server.get(), (struct sockaddr *)&sin, sizeof(sin)), + SyscallSucceeds()); + + FileDescriptor client = + ASSERT_NO_ERRNO_AND_VALUE(Socket(AF_INET, SOCK_DGRAM, 0)); + ASSERT_THAT(sendto(client.get(), "a", 1, 0, (struct sockaddr *)&sin, + sizeof(sin)), SyscallSucceedsWithValue(1)); + + char buf[128]; + ASSERT_THAT(recvfrom(server.get(), buf, sizeof(buf), 0, NULL, NULL), + SyscallSucceedsWithValue(1)); + + uint64_t newOutDatagrams; + uint64_t newInDatagrams; + snmp = ASSERT_NO_ERRNO_AND_VALUE(GetContents("/proc/net/snmp")); + newOutDatagrams = ASSERT_NO_ERRNO_AND_VALUE(GetSNMPMetricFromProc(snmp, "Udp", "OutDatagrams")); + newInDatagrams = ASSERT_NO_ERRNO_AND_VALUE(GetSNMPMetricFromProc(snmp, "Udp", "InDatagrams")); + + EXPECT_EQ(oldOutDatagrams, newOutDatagrams - 1); + EXPECT_EQ(oldInDatagrams, newInDatagrams - 1); +} + } // namespace } // namespace testing } // namespace gvisor -- cgit v1.2.3