Путь: Toys/Net, команды версии: Ver.4 Ver.9 netstat Комментарии в файле netstat.c :
Исходный текст в файле netstat.c #define FOR_netstat
#include "toys.h"
#include <net/route.h>
GLOBALS(
struct num_cache *inodes;
int wpad;
)
struct num_cache {
struct num_cache *next;
long long num;
char data[];
};
// Find num in cache
static struct num_cache *get_num_cache(struct num_cache *cache, long long num)
{
while (cache) {
if (num==cache->num) return cache;
cache = cache->next;
}
return 0;
}
// Uniquely add num+data to cache. Updates *cache, returns pointer to existing
// entry if it was already there.
static struct num_cache *add_num_cache(struct num_cache **cache, long long num,
void *data, int len)
{
struct num_cache *old = get_num_cache(*cache, num);
if (old) return old;
old = xzalloc(sizeof(struct num_cache)+len);
old->next = *cache;
old->num = num;
memcpy(old->data, data, len);
*cache = old;
return 0;
}
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-pos<count) pos = len-count;
if (se) sprintf(buf+pos, ":%s", se->s_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;
} |
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