selftests: mptcp: Add a tool to get specific msk_info
authorGang Yan <yangang@kylinos.cn>
Fri, 28 Feb 2025 14:38:35 +0000 (15:38 +0100)
committerJakub Kicinski <kuba@kernel.org>
Wed, 5 Mar 2025 00:57:37 +0000 (16:57 -0800)
This patch enables the retrieval of the mptcp_info structure corresponding
to a specified MPTCP socket (msk). When multiple MPTCP connections are
present, specific information can be obtained for a given connection
through the 'mptcp_diag_dump_one' by using the 'token' associated with
the msk.

Signed-off-by: Gang Yan <yangang@kylinos.cn>
Co-developed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250228-net-next-mptcp-coverage-small-opti-v1-1-f933c4275676@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
tools/testing/selftests/net/mptcp/Makefile
tools/testing/selftests/net/mptcp/mptcp_diag.c [new file with mode: 0644]

index c76525f..340e1a7 100644 (file)
@@ -7,7 +7,7 @@ CFLAGS += -Wall -Wl,--no-as-needed -O2 -g -I$(top_srcdir)/usr/include $(KHDR_INC
 TEST_PROGS := mptcp_connect.sh pm_netlink.sh mptcp_join.sh diag.sh \
              simult_flows.sh mptcp_sockopt.sh userspace_pm.sh
 
-TEST_GEN_FILES = mptcp_connect pm_nl_ctl mptcp_sockopt mptcp_inq
+TEST_GEN_FILES = mptcp_connect pm_nl_ctl mptcp_sockopt mptcp_inq mptcp_diag
 
 TEST_FILES := mptcp_lib.sh settings
 
diff --git a/tools/testing/selftests/net/mptcp/mptcp_diag.c b/tools/testing/selftests/net/mptcp/mptcp_diag.c
new file mode 100644 (file)
index 0000000..284286c
--- /dev/null
@@ -0,0 +1,272 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2025, Kylin Software */
+
+#include <linux/sock_diag.h>
+#include <linux/rtnetlink.h>
+#include <linux/inet_diag.h>
+#include <linux/netlink.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <linux/tcp.h>
+
+#include <unistd.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <stdio.h>
+
+#ifndef IPPROTO_MPTCP
+#define IPPROTO_MPTCP 262
+#endif
+
+struct mptcp_info {
+       __u8    mptcpi_subflows;
+       __u8    mptcpi_add_addr_signal;
+       __u8    mptcpi_add_addr_accepted;
+       __u8    mptcpi_subflows_max;
+       __u8    mptcpi_add_addr_signal_max;
+       __u8    mptcpi_add_addr_accepted_max;
+       __u32   mptcpi_flags;
+       __u32   mptcpi_token;
+       __u64   mptcpi_write_seq;
+       __u64   mptcpi_snd_una;
+       __u64   mptcpi_rcv_nxt;
+       __u8    mptcpi_local_addr_used;
+       __u8    mptcpi_local_addr_max;
+       __u8    mptcpi_csum_enabled;
+       __u32   mptcpi_retransmits;
+       __u64   mptcpi_bytes_retrans;
+       __u64   mptcpi_bytes_sent;
+       __u64   mptcpi_bytes_received;
+       __u64   mptcpi_bytes_acked;
+       __u8    mptcpi_subflows_total;
+       __u8    reserved[3];
+       __u32   mptcpi_last_data_sent;
+       __u32   mptcpi_last_data_recv;
+       __u32   mptcpi_last_ack_recv;
+};
+
+static void die_perror(const char *msg)
+{
+       perror(msg);
+       exit(1);
+}
+
+static void die_usage(int r)
+{
+       fprintf(stderr, "Usage: mptcp_diag -t\n");
+       exit(r);
+}
+
+static void send_query(int fd, __u32 token)
+{
+       struct sockaddr_nl nladdr = {
+               .nl_family = AF_NETLINK
+       };
+       struct {
+               struct nlmsghdr nlh;
+               struct inet_diag_req_v2 r;
+       } req = {
+               .nlh = {
+                       .nlmsg_len = sizeof(req),
+                       .nlmsg_type = SOCK_DIAG_BY_FAMILY,
+                       .nlmsg_flags = NLM_F_REQUEST
+               },
+               .r = {
+                       .sdiag_family = AF_INET,
+                       /* Real proto is set via INET_DIAG_REQ_PROTOCOL */
+                       .sdiag_protocol = IPPROTO_TCP,
+                       .id.idiag_cookie[0] = token,
+               }
+       };
+       struct rtattr rta_proto;
+       struct iovec iov[6];
+       int iovlen = 1;
+       __u32 proto;
+
+       req.r.idiag_ext |= (1 << (INET_DIAG_INFO - 1));
+       proto = IPPROTO_MPTCP;
+       rta_proto.rta_type = INET_DIAG_REQ_PROTOCOL;
+       rta_proto.rta_len = RTA_LENGTH(sizeof(proto));
+
+       iov[0] = (struct iovec) {
+               .iov_base = &req,
+               .iov_len = sizeof(req)
+       };
+       iov[iovlen] = (struct iovec){ &rta_proto, sizeof(rta_proto)};
+       iov[iovlen + 1] = (struct iovec){ &proto, sizeof(proto)};
+       req.nlh.nlmsg_len += RTA_LENGTH(sizeof(proto));
+       iovlen += 2;
+       struct msghdr msg = {
+               .msg_name = &nladdr,
+               .msg_namelen = sizeof(nladdr),
+               .msg_iov = iov,
+               .msg_iovlen = iovlen
+       };
+
+       for (;;) {
+               if (sendmsg(fd, &msg, 0) < 0) {
+                       if (errno == EINTR)
+                               continue;
+                       die_perror("sendmsg");
+               }
+               break;
+       }
+}
+
+static void parse_rtattr_flags(struct rtattr *tb[], int max, struct rtattr *rta,
+                              int len, unsigned short flags)
+{
+       unsigned short type;
+
+       memset(tb, 0, sizeof(struct rtattr *) * (max + 1));
+       while (RTA_OK(rta, len)) {
+               type = rta->rta_type & ~flags;
+               if (type <= max && !tb[type])
+                       tb[type] = rta;
+               rta = RTA_NEXT(rta, len);
+       }
+}
+
+static void print_info_msg(struct mptcp_info *info)
+{
+       printf("Token & Flags\n");
+       printf("token:        %x\n", info->mptcpi_token);
+       printf("flags:        %x\n", info->mptcpi_flags);
+       printf("csum_enabled: %u\n", info->mptcpi_csum_enabled);
+
+       printf("\nBasic Info\n");
+       printf("subflows:              %u\n", info->mptcpi_subflows);
+       printf("subflows_max:          %u\n", info->mptcpi_subflows_max);
+       printf("subflows_total:        %u\n", info->mptcpi_subflows_total);
+       printf("local_addr_used:       %u\n", info->mptcpi_local_addr_used);
+       printf("local_addr_max:        %u\n", info->mptcpi_local_addr_max);
+       printf("add_addr_signal:       %u\n", info->mptcpi_add_addr_signal);
+       printf("add_addr_accepted:     %u\n", info->mptcpi_add_addr_accepted);
+       printf("add_addr_signal_max:   %u\n", info->mptcpi_add_addr_signal_max);
+       printf("add_addr_accepted_max: %u\n", info->mptcpi_add_addr_accepted_max);
+
+       printf("\nTransmission Info\n");
+       printf("write_seq:        %llu\n", info->mptcpi_write_seq);
+       printf("snd_una:          %llu\n", info->mptcpi_snd_una);
+       printf("rcv_nxt:          %llu\n", info->mptcpi_rcv_nxt);
+       printf("last_data_sent:   %u\n", info->mptcpi_last_data_sent);
+       printf("last_data_recv:   %u\n", info->mptcpi_last_data_recv);
+       printf("last_ack_recv:    %u\n", info->mptcpi_last_ack_recv);
+       printf("retransmits:      %u\n", info->mptcpi_retransmits);
+       printf("retransmit bytes: %llu\n", info->mptcpi_bytes_retrans);
+       printf("bytes_sent:       %llu\n", info->mptcpi_bytes_sent);
+       printf("bytes_received:   %llu\n", info->mptcpi_bytes_received);
+       printf("bytes_acked:      %llu\n", info->mptcpi_bytes_acked);
+}
+
+static void parse_nlmsg(struct nlmsghdr *nlh)
+{
+       struct inet_diag_msg *r = NLMSG_DATA(nlh);
+       struct rtattr *tb[INET_DIAG_MAX + 1];
+
+       parse_rtattr_flags(tb, INET_DIAG_MAX, (struct rtattr *)(r + 1),
+                          nlh->nlmsg_len - NLMSG_LENGTH(sizeof(*r)),
+                          NLA_F_NESTED);
+
+       if (tb[INET_DIAG_INFO]) {
+               int len = RTA_PAYLOAD(tb[INET_DIAG_INFO]);
+               struct mptcp_info *info;
+
+               /* workaround fort older kernels with less fields */
+               if (len < sizeof(*info)) {
+                       info = alloca(sizeof(*info));
+                       memcpy(info, RTA_DATA(tb[INET_DIAG_INFO]), len);
+                       memset((char *)info + len, 0, sizeof(*info) - len);
+               } else {
+                       info = RTA_DATA(tb[INET_DIAG_INFO]);
+               }
+               print_info_msg(info);
+       }
+}
+
+static void recv_nlmsg(int fd, struct nlmsghdr *nlh)
+{
+       char rcv_buff[8192];
+       struct sockaddr_nl rcv_nladdr = {
+               .nl_family = AF_NETLINK
+       };
+       struct iovec rcv_iov = {
+               .iov_base = rcv_buff,
+               .iov_len = sizeof(rcv_buff)
+       };
+       struct msghdr rcv_msg = {
+               .msg_name = &rcv_nladdr,
+               .msg_namelen = sizeof(rcv_nladdr),
+               .msg_iov = &rcv_iov,
+               .msg_iovlen = 1
+       };
+       int len;
+
+       len = recvmsg(fd, &rcv_msg, 0);
+       nlh = (struct nlmsghdr *)rcv_buff;
+
+       while (NLMSG_OK(nlh, len)) {
+               if (nlh->nlmsg_type == NLMSG_DONE) {
+                       printf("NLMSG_DONE\n");
+                       break;
+               } else if (nlh->nlmsg_type == NLMSG_ERROR) {
+                       struct nlmsgerr *err;
+
+                       err = (struct nlmsgerr *)NLMSG_DATA(nlh);
+                       printf("Error %d:%s\n",
+                              -(err->error), strerror(-(err->error)));
+                       break;
+               }
+               parse_nlmsg(nlh);
+               nlh = NLMSG_NEXT(nlh, len);
+       }
+}
+
+static void get_mptcpinfo(__u32 token)
+{
+       struct nlmsghdr *nlh = NULL;
+       int fd;
+
+       fd = socket(AF_NETLINK, SOCK_RAW, NETLINK_SOCK_DIAG);
+       if (fd < 0)
+               die_perror("Netlink socket");
+
+       send_query(fd, token);
+       recv_nlmsg(fd, nlh);
+
+       close(fd);
+}
+
+static void parse_opts(int argc, char **argv, __u32 *target_token)
+{
+       int c;
+
+       if (argc < 2)
+               die_usage(1);
+
+       while ((c = getopt(argc, argv, "ht:")) != -1) {
+               switch (c) {
+               case 'h':
+                       die_usage(0);
+                       break;
+               case 't':
+                       sscanf(optarg, "%x", target_token);
+                       break;
+               default:
+                       die_usage(1);
+                       break;
+               }
+       }
+}
+
+int main(int argc, char *argv[])
+{
+       __u32 target_token;
+
+       parse_opts(argc, argv, &target_token);
+       get_mptcpinfo(target_token);
+
+       return 0;
+}
+