Linux NetLink sockets implement similar SS commands, statistics sockets, and TCP information

Reference to the source code of the SS

and NetLink related information: http://blog.csdn.net/scdxmoe/article/details/27711205

The implementation results are:

GCC Netlink_dig_530_7.c-o netlink_dig_530_7
./netlink_dig_530_7

State family l.addr L.port r.addr R.rport LISTEN af_inet localhost 53 0.0.0.0 0 LISTEN af_inet (NULL) 21 0.0.0.0 0 LISTEN af_inet (NULL) 22 0.0.0.0 0 LISTEN af_inet (NULL) 22 0.0.0.0 0 LISTEN af_inet localhost 631 0.0.0.0 0 LISTEN af_inet (null) 12865 0.0.0.0 0 Estab af_inet ubuntu.local 59208 91.189.89.134 80 Estab af_inet ubuntu.local 22 192.168.0.248 9689 Estab af_inet ubuntu.local 22 192.168.0.248 9295 Estab af_inet ubuntu.local 35531 91.189.94.25 80 Estab af_inet ubuntu.local 22 192.168.0.248 9691

the experiment in this paper does not implement how to get the window value of TCP CWnd and RTT values, in the SS source I saw him using the/proc.

file to achieve the acquisition window and RTT value, how to use NetLink socket implementation? Also ask you to advise
Source:

#include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <string.h> #include < fcntl.h> #include <errno.h> #include <string.h> #include <asm/types.h> #include <sys/socket.h > #include <linux/netlink.h> #include <linux/inet_diag.h> #include <netinet/tcp.h> #include <    Netdb.h> #include <arpa/inet.h>struct sk_req {struct NLMSGHDR nlh; struct inet_diag_req r;};        typedef struct{__U8 Family; __u8 Bytelen; __s16 Bitlen; __u32 flags; __u32 data[8];} inet_prefix;/*struct namerec{        struct Namerec *next;        const char *name; Inet_prefix addr;};        */struct tcpstat{Inet_prefix Local;        Inet_prefix remote;        int lport;        int rport;        int state;        RQ int, Wq; int timer;        RQ int, Wq;        int timer;        int timeout;        int retrs; UnsigneD ino;        int probes;        unsigned uid;        int refcnt;        unsigned long long SK; int RTO, ATO, Qack, CWnd, Ssthresh;}; enum {ss_unknown, ss_established, Ss_syn_sent, Ss_syn_recv, Ss_fin_wait1, Ss_fi N_wait2, Ss_time_wait, Ss_close, ss_close_wait, Ss_last_ack, Ss_listen, Ss_closi NG, ss_max};static const char *sstate_name[] = {"UNKNOWN", [ss_established] = "Estab", [Ss_sy N_sent] = "Syn-sent", [ss_syn_recv] = "Syn-recv", [ss_fin_wait1] = "Fin-wait-1", [ss_fin_wait2] = "FI        N-wait-2 ", [ss_time_wait] =" Time-wait ", [ss_close] =" Unconn ", [ss_close_wait] =" Close-wait ", [Ss_last_ack] = "Last-ack", [ss_listen] = "LISTEN", [ss_closing] = "CLOSING",};/* Base info structure. It contains socket identity (addrs/ports/cookie) * And, alas, the informationShown by netstat./* Base info structure. It contains socket identity (addrs/ports/cookie) * And, alas, the information shown by Netstat.      struct NLMSGHDR {__u32 nlmsg_len;     Length of message including header __u16 Nlmsg_type;    Message content __u16 nlmsg_flags;      Additional flags __u32 nlmsg_seq;      Sequence number __u32 nlmsg_pid;        Sending process Port ID};*///#ifdef resolve_hostnamesstruct namerec{struct Namerec *next;        const char *name; Inet_prefix addr;};        #define Nhash 257static struct namerec *nht[nhash];static const char *resolve_address (const void *addr, int len, int af) {        struct Namerec *n;        struct Hostent *h_ent;        unsigned hash;        static int notfirst; if (AF = = Af_inet6 && ((__u32*) addr) [0] = = 0 && ((__u32*) addr) [1] = = 0 && ((__u32*) addr                ) [2] = = htonl (0xffff)) {AF = af_inet;                Addr + = 12;        len = 4;        } hash = * (__U32 *) (addr + len-4)% Nhash; for (n = nht[hash]; n n = n->next) {if (n->addr.family = = af && n->ad Dr.bytelen = = Len && memcmp (n->addr.data, addr, len) = = 0) return n-&  Gt;name;        MEMCMP (n->addr.data, addr, len) = = 0) return n->name;        } if ((n = malloc (sizeof (*n)) = = null) return null;        n->addr.family = AF;        N->addr.bytelen = Len;        N->name = NULL;        memcpy (n->addr.data, addr, Len);        N->next = Nht[hash];        Nht[hash] = n;        if (++notfirst = = 1) sethostent (1);        Fflush (stdout);        if (h_ent = gethostbyaddr (addr, Len, af)) = NULL) N->name = StrDup (h_ent->h_name); /* Even if we fail, "negative" entry is remembered. */REturn N->name;} #endifconst char *rt_addr_n2a (int af, int len, const void *addr, char *buf, int buflen) {switch (AF) {CAs        E af_inet:case af_inet6:return inet_ntop (AF, addr, buf, Buflen);        /*case Af_ipx:return ipx_ntop (AF, addr, buf, Buflen);                Case af_decnet: {struct Dn_naddr DNA = {2, {0, 0,}};                memcpy (dna.a_addr, addr, 2);        Return Dnet_ntop (AF, &dna, buf, Buflen);        }*/Default:return "???";                }}void print_info (struct inet_diag_msg *pkg,struct nlmsghdr *h) {struct Tcpstat s;                Char buf[1024];                const char *AP = buf;//Store IP address char buf2[1024];                const char *AP2 = buf2;//holds IP address struct inet_diag_msg *r = Nlmsg_data (h);                S.state = r->idiag_state;                s.local.family = s.remote.family = r->idiag_family; S. Lport = Ntohs (R->id.idiag_sport);                S.rport = Ntohs (R->id.idiag_dport);                s.local.family = s.remote.family = r->idiag_family;                if (s.local.family = = af_inet) {//here print S.local.bytelen = S.remote.bytelen = 4;                } else {S.local.bytelen = S.remote.bytelen = 16;                } memcpy (S.local.data, R-&GT;ID.IDIAG_SRC, S.local.bytelen);                memcpy (S.remote.data, R-&GT;ID.IDIAG_DST, S.local.bytelen); printf ("\n%-*s%-*s%-*s%-*s%-*s%-*s\n", Ten, "state", "Family", "l.addr", Ten, "L.port", "r.addr", Ten, "R.rport"                ");                printf ("%-*s", ten, Sstate_name[s.state]);                printf ("%-*s", Ten, "af_inet");                printf ("\ n--------------\ n");                Const Inet_prefix *a=&s.remote;                const void *ADDR = a->data;                Ap=resolve_address (&s.local.data,4,af_inet); PrinTF ("%-*s", p, AP);                printf ("%-*d", 10,s.lport);                Ap2=resolve_address (&s.remote.data,4,af_inet);                AP2=RT_ADDR_N2A (af_inet,4,addr,buf2,sizeof (BUF2));                printf ("%-*s", AP2);                printf ("%-*d\n", 10,s.rport);                printf ("L.port:%-*d r.prot:%-*d\n", 10,s.lport, 10,s.rport);                 printf ("idiag_state:%d\n", pkg->idiag_state);                printf ("idiag_state:%d\n", pkg->idiag_state); printf ("family:%s\n", pkg->idiag_family = = af_inet?       "Af_inet": "Af_inet6");                printf ("dport:%d, sprot:%d\n", Ntohs (Pkg->id.idiag_sport), Ntohs (Pkg->id.idiag_sport)); printf ("idiag_state:%d\n", Pkg->idiag_state);}    int main (int argc, char **argv) {int fd;    struct Sk_req req;    struct SOCKADDR_NL dest_addr;    struct MSGHDR msg;    Char buf[8192];    Char src_ip[20];    Char dest_ip[20];    struct Iovec Iov; if (FD = socket (Af_netlink, soCk_raw, Netlink_inet_diag)) < 0) {//eprint (__line__, errno, "socket");        printf ("Socket error\n");    return-1; }req.nlh.nlmsg_len = sizeof (req); req.nlh.nlmsg_type = Tcpdiag_getsock;req.nlh.nlmsg_flags = Nlm_f_request | Nlm_f_root;req.nlh.nlmsg_pid = 0;memset (&AMP;REQ.R, 0, sizeof (REQ.R)); req.r.idiag_family = Af_inet;req.r.idiag_ states = ((1 << tcp_closing + 1)-1); iov.iov_base = &req;iov.iov_len = sizeof (req); memset (&dest_addr, 0, si Zeof (DEST_ADDR));d est_addr.nl_family = Af_netlink;memset (&dest_addr, 0, sizeof (DEST_ADDR));d est_addr.nl_family = Af_netlink;dest_addr.nl_pid = 0;dest_addr.nl_groups = 0;memset (&msg, 0, sizeof (msg)); msg.msg_name = (void *) & Dest_addr;msg.msg_namelen = sizeof (DEST_ADDR); Msg.msg_iov = &iov;msg.msg_iovlen = 1;if (sendmsg (FD, &msg, 0)    < 0) {//eprint (__line__, errno, "sendmsg");        printf ("Socket error\n"); return-1;} printf ("\n%-*s%-*s%-*s%-*s%-*s%-*s\n", Ten, "State", Ten, "FamilY "," l.addr "," L.port "," 0 "," r.addr "," R.rport ") memset (buf,, sizeof (BUF)); iov.iov_base = Buf;iov.iov_len =    sizeof (BUF); while (1) {int status;    struct NLMSGHDR *h;    msg = (struct MSGHDR) {(void *) &dest_addr, sizeof (DEST_ADDR), &iov, 1, NULL, 0, 0}; Status = Recvmsg (FD, &msg, 0); The return value of the//RECVMSG function is the number of bytes read, if (Status < 0) {if (errno = = eintr) CO        Ntinue;        Eprint (__line__, errno, "recvmsg");                printf ("Socket error\n");    Continue        } if (status = = 0) {printf ("EOF on netlink\n");        Close (FD);    return 0;                            } h = (struct NLMSGHDR *) buf;//#define NLMSG_OK (Nlh,len) (len) >= (int) sizeof (struct NLMSGHDR) && (NLH)->nlmsg_len >= sizeof (struct NLMSGHDR) && (NLH)                Nlmsg_len <= (len)) while (Nlmsg_ok (h, status)) {struct inet_diag_msg *pkg = NULL; /* struct INET_diag_msg *pkg = NULL;        /* struct INET_DIAG_MSG {__u8 idiag_family;        __u8 idiag_state;        __u8 Idiag_timer;        __u8 Idiag_retrans;        struct Inet_diag_sockid ID;        __u32 Idiag_expires;        __u32 Idiag_rqueue;        __u32 Idiag_wqueue;        __u32 Idiag_uid;                __u32 Idiag_inode;};            */if (H->nlmsg_type = = Nlmsg_done) {close (FD);            printf ("nlmsg_done\n");        return 0;            } if (H->nlmsg_type = = nlmsg_error) {struct Nlmsgerr *err;            Err = (struct nlmsgerr*) nlmsg_data (h);            fprintf (stderr, "%d Error%d:%s\n", __line__,-(Err->error), Strerror (-(Err->error)));            Close (FD);            printf ("nlmsg_error\n");        return 0;        pkg = (struct inet_diag_msg *) nlmsg_data (h);        Print_skinfo (pkg); printf ("\n%-*s%-*s%-*s%-*s%-*s%-*s\n", Ten, "state", "family", ten, "l.addr", Ten, "L.port", Ten, "r.addr", Ten, "R.rport");        Print_info (PKG,H);        Get_tcp_state (pkg->idiag_state);                h = Nlmsg_next (h, status); #define NLMSG_NEXT (Nlh,len) ((len)-= Nlmsg_align ((NLH)->nlmsg_len), (struct NLM sghdr*) (((char*) (NLH)) + nlmsg_align ((NLH)->nlmsg_len))//#define NLMSG_ALIGN (len) ((len) +nlmsg_align                                                                                                                                                                           TO-1) & ~ (nlmsg_alignto-1))}//while}//whileclose (FD); return 0;}