/* netstat.c - Display Linux networking subsystem. * * Copyright 2012 Ranjan Kumar * Copyright 2013 Kyungwan Han * * Not in SUSv4. * USE_NETSTAT(NEWTOY(netstat, "pWrxwutneal", TOYFLAG_BIN)) config NETSTAT bool "netstat" default y help usage: netstat [-pWrxwutneal] Display networking information. Default is netstat -tuwx -r Routing table -a All sockets (not just connected) -l Listening server sockets -t TCP sockets -u UDP sockets -w Raw sockets -x Unix sockets -e Extended info -n Don't resolve names -W Wide display -p Show PID/program name of sockets */ #define FOR_netstat #include "toys.h" #include GLOBALS( struct num_cache *inodes; int wpad; ) static void addr2str(int af, void *addr, unsigned port, char *buf, int len, char *proto) { char pres[INET6_ADDRSTRLEN]; struct servent *se = 0; int pos, count; if (!inet_ntop(af, addr, pres, sizeof(pres))) perror_exit("inet_ntop"); if (FLAG(n) || !port) { strcpy(buf, pres); } else { struct addrinfo hints, *result, *rp; char cut[4]; memset(&hints, 0, sizeof(struct addrinfo)); hints.ai_family = af; if (!getaddrinfo(pres, NULL, &hints, &result)) { socklen_t sock_len = (af == AF_INET) ? sizeof(struct sockaddr_in) : sizeof(struct sockaddr_in6); // We assume that a failing getnameinfo dosn't stomp "buf" here. for (rp = result; rp; rp = rp->ai_next) if (!getnameinfo(rp->ai_addr, sock_len, buf, 256, 0, 0, 0)) break; freeaddrinfo(result); buf[len] = 0; } // getservbyport() doesn't understand proto "tcp6", so truncate memcpy(cut, proto, 3); cut[3] = 0; se = getservbyport(htons(port), cut); } if (!strcmp(buf, "::")) strcpy(buf, "[::]"); // Append :service or :* if port == 0. if (se) { count = snprintf(0, 0, ":%s", se->s_name); // NI_MAXSERV == 32, which is greater than our minimum field width. // (Although the longest service name on Debian in 2021 is only 16 bytes.) if (count>=len) { count = len-1; se->s_name[count] = 0; } } else count = port ? snprintf(0, 0, ":%u", port) : 2; // We always show the port, even if that means clobbering the end of the host. pos = strlen(buf); if (len-poss_name); else sprintf(buf+pos, port ? ":%u" : ":*", port); } // Display info for tcp/udp/raw static void show_ip(char *fname) { char *ss_state = "UNKNOWN", buf[12], *s, *label = strrchr(fname, '/')+1; char *state_label[] = {"", "ESTABLISHED", "SYN_SENT", "SYN_RECV", "FIN_WAIT1", "FIN_WAIT2", "TIME_WAIT", "CLOSE", "CLOSE_WAIT", "LAST_ACK", "LISTEN", "CLOSING", "UNKNOWN"}; FILE *fp = xfopen(fname, "r"); // Skip header. fgets(toybuf, sizeof(toybuf), fp); while (fgets(toybuf, sizeof(toybuf), fp)) { char lip[256], rip[256]; union { struct {unsigned u; unsigned char b[4];} i4; struct {struct {unsigned a, b, c, d;} u; unsigned char b[16];} i6; } laddr, raddr; unsigned lport, rport, state, txq, rxq, num, uid, af = AF_INET6; unsigned long inode; // Try ipv6, then try ipv4 if (16 != sscanf(toybuf, " %d: %8x%8x%8x%8x:%x %8x%8x%8x%8x:%x %x %x:%x %*X:%*X %*X %d %*d %ld", &num, &laddr.i6.u.a, &laddr.i6.u.b, &laddr.i6.u.c, &laddr.i6.u.d, &lport, &raddr.i6.u.a, &raddr.i6.u.b, &raddr.i6.u.c, &raddr.i6.u.d, &rport, &state, &txq, &rxq, &uid, &inode)) { af = AF_INET; if (10 != sscanf(toybuf, " %d: %x:%x %x:%x %x %x:%x %*X:%*X %*X %d %*d %ld", &num, &laddr.i4.u, &lport, &raddr.i4.u, &rport, &state, &txq, &rxq, &uid, &inode)) continue; } // Should we display this? (listening or all or TCP/UDP/RAW) if (!(FLAG(l) && (!rport && (state&0xA))) && !FLAG(a) && !(rport&0x70)) continue; addr2str(af, &laddr, lport, lip, TT.wpad, label); addr2str(af, &raddr, rport, rip, TT.wpad, label); // Display data s = label; if (strstart(&s, "tcp")) { int sz = ARRAY_LEN(state_label); if (!state || state >= sz) state = sz-1; ss_state = state_label[state]; } else if (strstart(&s, "udp")) { if (state == 1) ss_state = state_label[state]; else if (state == 7) ss_state = ""; } else if (strstart(&s, "raw")) sprintf(ss_state = buf, "%u", state); printf("%-6s%6d%7d %*.*s %*.*s %-11s", label, rxq, txq, -TT.wpad, TT.wpad, lip, -TT.wpad, TT.wpad, rip, ss_state); if (FLAG(e)) { if (FLAG(n)) sprintf(s = toybuf, "%d", uid); else s = getusername(uid); printf(" %-10s %-11ld", s, inode); } if (FLAG(p)) { struct num_cache *nc = get_num_cache(TT.inodes, inode); printf(" %s", nc ? nc->data : "-"); } xputc('\n'); } fclose(fp); } static void show_unix_sockets(void) { char *types[] = {"","STREAM","DGRAM","RAW","RDM","SEQPACKET","DCCP","PACKET"}, *states[] = {"","LISTENING","CONNECTING","CONNECTED","DISCONNECTING"}, *filename = 0; unsigned long refcount, flags, type, state, inode; FILE *fp = xfopen("/proc/net/unix", "r"); // Skip header. fgets(toybuf, sizeof(toybuf), fp); while (fscanf(fp, "%*p: %lX %*X %lX %lX %lX %lu%m[^\n]", &refcount, &flags, &type, &state, &inode, &filename) >= 5) { // Linux exports only SO_ACCEPTCON since 2.3.15pre3 in 1999, but let's // filter in case they add more someday. flags &= 1<<16; // Only show unconnected listening sockets with -a or -l. if (state==1 && flags && !(FLAG(a) || FLAG(l))) continue; if (type==10) type = 7; // move SOCK_PACKET into line if (type>ARRAY_LEN(types)) type = 0; if (state>ARRAY_LEN(states) || (state==1 && !flags)) state = 0; if (state!=1 && FLAG(l)) continue; sprintf(toybuf, "[ %s]", flags ? "ACC " : ""); printf("unix %-6ld %-11s %-10s %-13s %-8lu ", refcount, toybuf, types[type], states[state], inode); if (FLAG(p)) { struct num_cache *nc = get_num_cache(TT.inodes, inode); printf("%-19.19s ", nc ? nc->data : "-"); } if (filename) { printf("%s\n", filename+!FLAG(p)); free(filename); filename = 0; } else xputc('\n'); } fclose(fp); } static int scan_pids(struct dirtree *node) { char *s = toybuf+256; struct dirent *entry; DIR *dp; int pid, dirfd; if (!node->parent) return DIRTREE_RECURSE; if (!(pid = atol(node->name))) return 0; sprintf(toybuf, "/proc/%d/cmdline", pid); if (!(readfile(toybuf, toybuf, 256))) return 0; sprintf(s, "%d/fd", pid); if (-1==(dirfd = openat(dirtree_parentfd(node), s, O_RDONLY))) return 0; if (!(dp = fdopendir(dirfd))) close(dirfd); else while ((entry = readdir(dp))) { s = toybuf+256; if (!readlinkat0(dirfd, entry->d_name, s, sizeof(toybuf)-256)) continue; // Can the "[0000]:" happen in a modern kernel? if (strstart(&s, "socket:[") || strstart(&s, "[0000]:")) { long long ll = atoll(s); sprintf(s, "%d/%s", pid, getbasename(toybuf)); add_num_cache(&TT.inodes, ll, s, strlen(s)+1); } } closedir(dp); return 0; } // extract inet4 route info from /proc/net/route file and display it. static void display_routes(void) { static const char flagchars[] = "GHRDMDAC"; static const unsigned flagarray[] = { RTF_GATEWAY, RTF_HOST, RTF_REINSTATE, RTF_DYNAMIC, RTF_MODIFIED }; unsigned dest, gate, mask; int flags, ref, use, metric, mss, win, irtt; char *out = toybuf, *flag_val; char iface[64]={0}; FILE *fp = xfopen("/proc/net/route", "r"); // Skip header. fgets(toybuf, sizeof(toybuf), fp); printf("Kernel IP routing table\n" "Destination\tGateway \tGenmask \tFlags %s Iface\n", !FLAG(e) ? " MSS Window irtt" : "Metric Ref Use"); while (fscanf(fp, "%63s%x%x%X%d%d%d%x%d%d%d", iface, &dest, &gate, &flags, &ref, &use, &metric, &mask, &mss, &win, &irtt) == 11) { char *destip = 0, *gateip = 0, *maskip = 0; // skip down interfaces. if (!(flags & RTF_UP)) continue; // TODO /proc/net/ipv6_route if (dest) { if (inet_ntop(AF_INET, &dest, out, 16)) destip = out; } else destip = FLAG(n) ? "0.0.0.0" : "default"; out += 16; if (gate) { if (inet_ntop(AF_INET, &gate, out, 16)) gateip = out; } else gateip = FLAG(n) ? "0.0.0.0" : "*"; out += 16; // TODO /24 //For Mask if (inet_ntop(AF_INET, &mask, out, 16)) maskip = out; else maskip = "?"; out += 16; //Get flag Values flag_val = out; *out++ = 'U'; for (dest = 0; dest < ARRAY_LEN(flagarray); dest++) if (flags&flagarray[dest]) *out++ = flagchars[dest]; *out = 0; if (flags & RTF_REJECT) *flag_val = '!'; printf("%-15.15s %-15.15s %-16s%-6s", destip, gateip, maskip, flag_val); if (!FLAG(e)) printf("%5d %-5d %6d %s\n", mss, win, irtt, iface); else printf("%-6d %-2d %7d %s\n", metric, ref, use, iface); } fclose(fp); } void netstat_main(void) { int tuwx = FLAG_t|FLAG_u|FLAG_w|FLAG_x; char *type = "w/o servers"; TT.wpad = FLAG(W) ? 51 : 23; if (!(toys.optflags&(FLAG_r|tuwx))) toys.optflags |= tuwx; if (FLAG(r)) display_routes(); if (!(toys.optflags&tuwx)) return; if (FLAG(a)) type = "servers and established"; else if (FLAG(l)) type = "only servers"; if (FLAG(p)) dirtree_read("/proc", scan_pids); if (toys.optflags&(FLAG_t|FLAG_u|FLAG_w)) { printf("Active Internet connections (%s)\n", type); printf("Proto Recv-Q Send-Q %*s %*s State ", -TT.wpad, "Local Address", -TT.wpad, "Foreign Address"); if (FLAG(e)) printf(" User Inode "); if (FLAG(p)) printf(" PID/Program Name"); xputc('\n'); if (FLAG(t)) { show_ip("/proc/net/tcp"); show_ip("/proc/net/tcp6"); } if (FLAG(u)) { show_ip("/proc/net/udp"); show_ip("/proc/net/udp6"); } if (FLAG(w)) { show_ip("/proc/net/raw"); show_ip("/proc/net/raw6"); } } if (FLAG(x)) { printf("Active UNIX domain sockets (%s)\n", type); printf("Proto RefCnt Flags Type State I-Node%sPath\n", FLAG(p) ? " PID/Program Name " : " "); show_unix_sockets(); } if (FLAG(p) && CFG_TOYBOX_FREE) llist_traverse(TT.inodes, free); toys.exitval = 0; }