Avoid fgets() into toybuf other than to skip header lines, preferring
fscanf() or xgetline() instead.
Remove the early returns if we fail to skip a header line (fixes #62).
Fix `netstat -xl` which was previously broken (because only -a would
include listening sockets).
Fix a variety of formatting issues, bringing the diff between toybox
netstat and net-tools netstat down (which was what I used for testing).
Use FLAG() more consistently.
---
toys/net/netstat.c | 143 ++++++++++++++++++++-------------------------
1 file changed, 62 insertions(+), 81 deletions(-)
From 43aff0a37623c2bbc747806ddb3d1b4bbdb0c8bb Mon Sep 17 00:00:00 2001
From: Elliott Hughes <e...@google.com>
Date: Sat, 6 Feb 2021 12:47:59 -0800
Subject: [PATCH] netstat: various fixes.
Avoid fgets() into toybuf other than to skip header lines, preferring
fscanf() or xgetline() instead.
Remove the early returns if we fail to skip a header line (fixes #62).
Fix `netstat -xl` which was previously broken (because only -a would
include listening sockets).
Fix a variety of formatting issues, bringing the diff between toybox
netstat and net-tools netstat down (which was what I used for testing).
Use FLAG() more consistently.
---
toys/net/netstat.c | 143 ++++++++++++++++++++-------------------------
1 file changed, 62 insertions(+), 81 deletions(-)
diff --git a/toys/net/netstat.c b/toys/net/netstat.c
index 23cd9f6d..24a2ceed 100644
--- a/toys/net/netstat.c
+++ b/toys/net/netstat.c
@@ -36,40 +36,25 @@ GLOBALS(
int wpad;
)
-// convert address into text format.
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;
- struct servent *ser = 0;
-// TODO lib/net.c has ntop()
- // Convert to numeric address
- if (!inet_ntop(af, addr, buf, 256)) {
- *buf = 0;
+ if (!inet_ntop(af, addr, pres, sizeof(pres))) perror_exit("inet_ntop");
- return;
- }
- buf[len] = 0;
- pos = strlen(buf);
-
- // If there's no port number, it's a local :* binding, nothing to look up.
- if (!port) {
- if (len-pos<2) pos = len-2;
- strcpy(buf+pos, ":*");
-
- return;
- }
-
-// TODO xgetaddrinfo()
- if (!FLAG(n)) {
+ 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(buf, NULL, &hints, &result)) {
+ if (!getaddrinfo(pres, NULL, &hints, &result)) {
socklen_t sock_len = (af == AF_INET) ? sizeof(struct sockaddr_in)
: sizeof(struct sockaddr_in6);
@@ -78,28 +63,31 @@ static void addr2str(int af, void *addr, unsigned port, char *buf, int len,
if (!getnameinfo(rp->ai_addr, sock_len, buf, 256, 0, 0, 0)) break;
freeaddrinfo(result);
buf[len] = 0;
- pos = strlen(buf);
}
- // Doesn't understand proto "tcp6", so truncate
+ // getservbyport() doesn't understand proto "tcp6", so truncate
memcpy(cut, proto, 3);
cut[3] = 0;
- ser = getservbyport(htons(port), cut);
+ se = getservbyport(htons(port), cut);
}
- // Append :service
- count = snprintf(0, 0, ":%u", port);
- if (ser) {
- count = snprintf(0, 0, ":%s", ser->s_name);
- // sheer paranoia
+ 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;
- ser->s_name[count] = 0;
+ 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 (ser) sprintf(buf+pos, ":%s", ser->s_name);
- else sprintf(buf+pos, ":%u", port);
+ if (se) sprintf(buf+pos, ":%s", se->s_name);
+ else sprintf(buf+pos, port ? ":%u" : ":*", port);
}
// Display info for tcp/udp/raw
@@ -109,10 +97,10 @@ static void show_ip(char *fname)
char *state_label[] = {"", "ESTABLISHED", "SYN_SENT", "SYN_RECV", "FIN_WAIT1",
"FIN_WAIT2", "TIME_WAIT", "CLOSE", "CLOSE_WAIT",
"LAST_ACK", "LISTEN", "CLOSING", "UNKNOWN"};
- FILE *fp = fopen(fname, "r");
+ FILE *fp = xfopen(fname, "r");
- if (!fp) return perror_msg("'%s'", fname);
- if(!fgets(toybuf, sizeof(toybuf), fp)) return; //skip header.
+ // Skip header.
+ fgets(toybuf, sizeof(toybuf), fp);
while (fgets(toybuf, sizeof(toybuf), fp)) {
char lip[256], rip[256];
@@ -120,7 +108,7 @@ static void show_ip(char *fname)
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, nitems;
+ unsigned lport, rport, state, txq, rxq, num, uid, af = AF_INET6;
unsigned long inode;
// Try ipv6, then try ipv4
@@ -131,19 +119,19 @@ static void show_ip(char *fname)
&raddr.i6.u.c, &raddr.i6.u.d, &rport, &state, &txq, &rxq,
&uid, &inode))
{
- nitems = AF_INET;
+ 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;
- } else nitems = AF_INET6;
+ }
// Should we display this? (listening or all or TCP/UDP/RAW)
if (!(FLAG(l) && (!rport && (state&0xA))) && !FLAG(a) && !(rport&0x70))
continue;
- addr2str(nitems, &laddr, lport, lip, TT.wpad, label);
- addr2str(nitems, &raddr, rport, rip, TT.wpad, label);
+ addr2str(af, &laddr, lport, lip, TT.wpad, label);
+ addr2str(af, &raddr, rport, rip, TT.wpad, label);
// Display data
s = label;
@@ -177,46 +165,43 @@ static void show_unix_sockets(void)
{
char *types[] = {"","STREAM","DGRAM","RAW","RDM","SEQPACKET","DCCP","PACKET"},
*states[] = {"","LISTENING","CONNECTING","CONNECTED","DISCONNECTING"},
- *s, *ss;
+ *filename = 0;
unsigned long refcount, flags, type, state, inode;
FILE *fp = xfopen("/proc/net/unix", "r");
- if(!fgets(toybuf, sizeof(toybuf), fp)) return; //skip header.
-
- while (fgets(toybuf, sizeof(toybuf), fp)) {
- unsigned offset = 0;
-
- // count = 6 or 7 (first field ignored, sockets don't always have filenames)
- if (6<sscanf(toybuf, "%*p: %lX %*X %lX %lX %lX %lu %n",
- &refcount, &flags, &type, &state, &inode, &offset))
- continue;
+ // 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
- if (state==1 && flags && !(toys.optflags&FLAG_a)) continue;
+ // 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 ",
+ 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 : "-");
+ printf("%-19.19s ", nc ? nc->data : "-");
}
- if (offset) {
- if ((ss = strrchr(s = toybuf+offset, '\n'))) *ss = 0;
- printf("%s", s);
- }
- xputc('\n');
+ if (filename) {
+ printf("%s\n", filename+!FLAG(p));
+ free(filename);
+ filename = 0;
+ } else xputc('\n');
}
-
fclose(fp);
}
@@ -265,18 +250,16 @@ static void display_routes(void)
char iface[64]={0};
FILE *fp = xfopen("/proc/net/route", "r");
- if(!fgets(toybuf, sizeof(toybuf), fp)) return; //skip header.
+ // Skip header.
+ fgets(toybuf, sizeof(toybuf), fp);
printf("Kernel IP routing table\n"
"Destination\tGateway \tGenmask \tFlags %s Iface\n",
- !(toys.optflags&FLAG_e) ? " MSS Window irtt" : "Metric Ref Use");
-
- while (fgets(toybuf, sizeof(toybuf), fp)) {
- char *destip = 0, *gateip = 0, *maskip = 0;
+ !FLAG(e) ? " MSS Window irtt" : "Metric Ref Use");
- if (11 != sscanf(toybuf, "%63s%x%x%X%d%d%d%x%d%d%d", iface, &dest,
- &gate, &flags, &ref, &use, &metric, &mask, &mss, &win, &irtt))
- break;
+ 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;
@@ -285,12 +268,12 @@ static void display_routes(void)
if (dest) {
if (inet_ntop(AF_INET, &dest, out, 16)) destip = out;
- } else destip = (toys.optflags&FLAG_n) ? "0.0.0.0" : "default";
+ } 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 = (toys.optflags&FLAG_n) ? "0.0.0.0" : "*";
+ } else gateip = FLAG(n) ? "0.0.0.0" : "*";
out += 16;
// TODO /24
@@ -311,27 +294,26 @@ static void display_routes(void)
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";
+ 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 = "established and";
- else if (FLAG(l)) type = "only";
+ 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 %s (%s servers)\n", "Internet connections", type);
+ 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 ");
@@ -353,10 +335,9 @@ void netstat_main(void)
}
if (FLAG(x)) {
- printf("Active %s (%s servers)\n", "UNIX domain sockets", type);
-
- printf("Proto RefCnt Flags\t Type\t State\t %s Path\n",
- FLAG(p) ? "PID/Program Name" : "I-Node");
+ 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();
}
--
2.30.0.478.g8a0d178c01-goog
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