#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include <linux/compiler.h>
#include <linux/inet_diag.h>
#include <linux/netlink.h>
#include <linux/rtnetlink.h>
#include <linux/sock_diag.h>
#include <linux/tcp.h>
#ifndef IPPROTO_MPTCP
#define IPPROTO_MPTCP 262
#endif
#define parse_rtattr_nested(tb, max, rta) \
(parse_rtattr_flags((tb), (max), RTA_DATA(rta), RTA_PAYLOAD(rta), \
NLA_F_NESTED))
struct params {
__u32 target_token;
char subflow_addrs[1024];
};
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;
};
enum {
MPTCP_SUBFLOW_ATTR_UNSPEC,
MPTCP_SUBFLOW_ATTR_TOKEN_REM,
MPTCP_SUBFLOW_ATTR_TOKEN_LOC,
MPTCP_SUBFLOW_ATTR_RELWRITE_SEQ,
MPTCP_SUBFLOW_ATTR_MAP_SEQ,
MPTCP_SUBFLOW_ATTR_MAP_SFSEQ,
MPTCP_SUBFLOW_ATTR_SSN_OFFSET,
MPTCP_SUBFLOW_ATTR_MAP_DATALEN,
MPTCP_SUBFLOW_ATTR_FLAGS,
MPTCP_SUBFLOW_ATTR_ID_REM,
MPTCP_SUBFLOW_ATTR_ID_LOC,
MPTCP_SUBFLOW_ATTR_PAD,
__MPTCP_SUBFLOW_ATTR_MAX
};
#define MPTCP_SUBFLOW_ATTR_MAX (__MPTCP_SUBFLOW_ATTR_MAX - 1)
#define MPTCP_SUBFLOW_FLAG_MCAP_REM _BITUL(0)
#define MPTCP_SUBFLOW_FLAG_MCAP_LOC _BITUL(1)
#define MPTCP_SUBFLOW_FLAG_JOIN_REM _BITUL(2)
#define MPTCP_SUBFLOW_FLAG_JOIN_LOC _BITUL(3)
#define MPTCP_SUBFLOW_FLAG_BKUP_REM _BITUL(4)
#define MPTCP_SUBFLOW_FLAG_BKUP_LOC _BITUL(5)
#define MPTCP_SUBFLOW_FLAG_FULLY_ESTABLISHED _BITUL(6)
#define MPTCP_SUBFLOW_FLAG_CONNECTED _BITUL(7)
#define MPTCP_SUBFLOW_FLAG_MAPVALID _BITUL(8)
#define rta_getattr(type, value) (*(type *)RTA_DATA(value))
static void __noreturn die_perror(const char *msg)
{
perror(msg);
exit(1);
}
static void die_usage(int r)
{
fprintf(stderr, "Usage:\n"
"mptcp_diag -t <token>\n"
"mptcp_diag -s \"<saddr>:<sport> <daddr>:<dport>\"\n");
exit(r);
}
static void send_query(int fd, struct inet_diag_req_v2 *r, __u32 proto)
{
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 = *r
};
struct rtattr rta_proto;
struct iovec iov[6];
int iovlen = 0;
iov[iovlen++] = (struct iovec) {
.iov_base = &req,
.iov_len = sizeof(req)
};
if (proto == IPPROTO_MPTCP) {
rta_proto.rta_type = INET_DIAG_REQ_PROTOCOL;
rta_proto.rta_len = RTA_LENGTH(sizeof(proto));
iov[iovlen++] = (struct iovec){ &rta_proto, sizeof(rta_proto)};
iov[iovlen++] = (struct iovec){ &proto, sizeof(proto)};
req.nlh.nlmsg_len += RTA_LENGTH(sizeof(proto));
}
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 print_subflow_info(struct rtattr *tb[])
{
u_int32_t flags = 0;
printf("It's a mptcp subflow, the subflow info:\n");
if (tb[MPTCP_SUBFLOW_ATTR_FLAGS]) {
char caps[32 + 1] = { 0 }, *cap = &caps[0];
flags = rta_getattr(__u32, tb[MPTCP_SUBFLOW_ATTR_FLAGS]);
if (flags & MPTCP_SUBFLOW_FLAG_MCAP_REM)
*cap++ = 'M';
if (flags & MPTCP_SUBFLOW_FLAG_MCAP_LOC)
*cap++ = 'm';
if (flags & MPTCP_SUBFLOW_FLAG_JOIN_REM)
*cap++ = 'J';
if (flags & MPTCP_SUBFLOW_FLAG_JOIN_LOC)
*cap++ = 'j';
if (flags & MPTCP_SUBFLOW_FLAG_BKUP_REM)
*cap++ = 'B';
if (flags & MPTCP_SUBFLOW_FLAG_BKUP_LOC)
*cap++ = 'b';
if (flags & MPTCP_SUBFLOW_FLAG_FULLY_ESTABLISHED)
*cap++ = 'e';
if (flags & MPTCP_SUBFLOW_FLAG_CONNECTED)
*cap++ = 'c';
if (flags & MPTCP_SUBFLOW_FLAG_MAPVALID)
*cap++ = 'v';
if (flags)
printf(" flags:%s", caps);
}
if (tb[MPTCP_SUBFLOW_ATTR_TOKEN_REM] &&
tb[MPTCP_SUBFLOW_ATTR_TOKEN_LOC] &&
tb[MPTCP_SUBFLOW_ATTR_ID_REM] &&
tb[MPTCP_SUBFLOW_ATTR_ID_LOC])
printf(" token:%04x(id:%u)/%04x(id:%u)",
rta_getattr(__u32, tb[MPTCP_SUBFLOW_ATTR_TOKEN_REM]),
rta_getattr(__u8, tb[MPTCP_SUBFLOW_ATTR_ID_REM]),
rta_getattr(__u32, tb[MPTCP_SUBFLOW_ATTR_TOKEN_LOC]),
rta_getattr(__u8, tb[MPTCP_SUBFLOW_ATTR_ID_LOC]));
if (tb[MPTCP_SUBFLOW_ATTR_MAP_SEQ])
printf(" seq:%llu",
rta_getattr(__u64, tb[MPTCP_SUBFLOW_ATTR_MAP_SEQ]));
if (tb[MPTCP_SUBFLOW_ATTR_MAP_SFSEQ])
printf(" sfseq:%u",
rta_getattr(__u32, tb[MPTCP_SUBFLOW_ATTR_MAP_SFSEQ]));
if (tb[MPTCP_SUBFLOW_ATTR_SSN_OFFSET])
printf(" ssnoff:%u",
rta_getattr(__u32, tb[MPTCP_SUBFLOW_ATTR_SSN_OFFSET]));
if (tb[MPTCP_SUBFLOW_ATTR_MAP_DATALEN])
printf(" maplen:%u",
rta_getattr(__u32, tb[MPTCP_SUBFLOW_ATTR_MAP_DATALEN]));
printf("\n");
}
static void parse_nlmsg(struct nlmsghdr *nlh, __u32 proto)
{
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 (proto == IPPROTO_MPTCP && tb[INET_DIAG_INFO]) {
int len = RTA_PAYLOAD(tb[INET_DIAG_INFO]);
struct mptcp_info *info;
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);
}
if (proto == IPPROTO_TCP && tb[INET_DIAG_ULP_INFO]) {
struct rtattr *ulpinfo[INET_ULP_INFO_MAX + 1] = { 0 };
parse_rtattr_nested(ulpinfo, INET_ULP_INFO_MAX,
tb[INET_DIAG_ULP_INFO]);
if (ulpinfo[INET_ULP_INFO_MPTCP]) {
struct rtattr *sfinfo[MPTCP_SUBFLOW_ATTR_MAX + 1] = { 0 };
parse_rtattr_nested(sfinfo, MPTCP_SUBFLOW_ATTR_MAX,
ulpinfo[INET_ULP_INFO_MPTCP]);
print_subflow_info(sfinfo);
} else {
printf("It's a normal TCP!\n");
}
}
}
static void recv_nlmsg(int fd, __u32 proto)
{
char rcv_buff[8192];
struct nlmsghdr *nlh = (struct nlmsghdr *)rcv_buff;
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);
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, proto);
nlh = NLMSG_NEXT(nlh, len);
}
}
static void get_mptcpinfo(__u32 token)
{
struct inet_diag_req_v2 r = {
.sdiag_family = AF_INET,
.sdiag_protocol = IPPROTO_TCP,
.idiag_ext = 1 << (INET_DIAG_INFO - 1),
.id.idiag_cookie[0] = token,
};
__u32 proto = IPPROTO_MPTCP;
int fd;
fd = socket(AF_NETLINK, SOCK_RAW, NETLINK_SOCK_DIAG);
if (fd < 0)
die_perror("Netlink socket");
send_query(fd, &r, proto);
recv_nlmsg(fd, proto);
close(fd);
}
static void get_subflow_info(char *subflow_addrs)
{
struct inet_diag_req_v2 r = {
.sdiag_family = AF_INET,
.sdiag_protocol = IPPROTO_TCP,
.idiag_ext = 1 << (INET_DIAG_INFO - 1),
.id.idiag_cookie[0] = INET_DIAG_NOCOOKIE,
.id.idiag_cookie[1] = INET_DIAG_NOCOOKIE,
};
char saddr[64], daddr[64];
int sport, dport;
int ret;
int fd;
ret = sscanf(subflow_addrs, "%[^:]:%d %[^:]:%d", saddr, &sport, daddr, &dport);
if (ret != 4)
die_perror("IP PORT Pairs has style problems!");
printf("%s:%d -> %s:%d\n", saddr, sport, daddr, dport);
fd = socket(AF_NETLINK, SOCK_RAW, NETLINK_SOCK_DIAG);
if (fd < 0)
die_perror("Netlink socket");
r.id.idiag_sport = htons(sport);
r.id.idiag_dport = htons(dport);
inet_pton(AF_INET, saddr, &r.id.idiag_src);
inet_pton(AF_INET, daddr, &r.id.idiag_dst);
send_query(fd, &r, IPPROTO_TCP);
recv_nlmsg(fd, IPPROTO_TCP);
}
static void parse_opts(int argc, char **argv, struct params *p)
{
int c;
if (argc < 2)
die_usage(1);
while ((c = getopt(argc, argv, "ht:s:")) != -1) {
switch (c) {
case 'h':
die_usage(0);
break;
case 't':
sscanf(optarg, "%x", &p->target_token);
break;
case 's':
strncpy(p->subflow_addrs, optarg,
sizeof(p->subflow_addrs) - 1);
break;
default:
die_usage(1);
break;
}
}
}
int main(int argc, char *argv[])
{
struct params p = { 0 };
parse_opts(argc, argv, &p);
if (p.target_token)
get_mptcpinfo(p.target_token);
if (p.subflow_addrs[0] != '\0')
get_subflow_info(p.subflow_addrs);
return 0;
}
