miniupnp/miniupnpd/portinuse.c

420 lines
11 KiB
C

/* $Id: portinuse.c,v 1.11 2020/10/30 21:11:52 nanard Exp $ */
/* vim: tabstop=4 shiftwidth=4 noexpandtab
* MiniUPnP project
* (c) 2007-2020 Thomas Bernard
* http://miniupnp.free.fr/ or https://miniupnp.tuxfamily.org/
* This software is subject to the conditions detailed
* in the LICENCE file provided within the distribution */
#if defined(__DragonFly__) || defined(__FreeBSD__)
#include <err.h>
#include <stdlib.h>
#endif
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <syslog.h>
#include <errno.h>
#include <time.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#if defined(__OpenBSD__)
#include <sys/queue.h>
#include <sys/select.h>
#include <kvm.h>
#include <fcntl.h>
#include <nlist.h>
#include <limits.h>
#include <net/route.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/in_pcb.h>
#endif
#if defined(__DragonFly__) || defined(__FreeBSD__)
#include <sys/socketvar.h>
#include <sys/sysctl.h>
/* sys/socketvar.h must be included above the following headers */
#include <netinet/in_pcb.h>
#include <netinet/tcp_var.h>
#endif
#include "macros.h"
#include "config.h"
#include "upnpglobalvars.h"
#include "getifaddr.h"
#include "portinuse.h"
#if defined(USE_NETFILTER)
#include "netfilter/iptcrdr.h"
#endif
#ifdef CHECK_PORTINUSE
#if defined(USE_NETFILTER)
/* Hardcoded for now. Ideally would come from .conf file */
# ifdef TOMATO
const char *chains_to_check[] = { "WANPREROUTING" , 0 };
# else
const char *chains_to_check[] = { "PREROUTING" , 0 };
# endif
#endif
int
port_in_use(const char *if_name,
unsigned eport, int proto,
const char *iaddr, unsigned iport)
{
int found = 0;
char ip_addr_str[INET_ADDRSTRLEN];
struct in_addr ip_addr;
#ifdef __linux__
/* linux code */
char line[256];
FILE *f;
const char * tcpfile = "/proc/net/tcp";
const char * udpfile = "/proc/net/udp";
#endif
if(getifaddr(if_name, ip_addr_str, INET_ADDRSTRLEN, &ip_addr, NULL) < 0) {
ip_addr.s_addr = 0;
ip_addr_str[0] = '\0';
}
syslog(LOG_DEBUG, "Check protocol %s for port %u on ext_if %s %s, %08X",
(proto==IPPROTO_TCP)?"tcp":"udp", eport, if_name,
ip_addr_str, (unsigned)ip_addr.s_addr);
/* Phase 1 : check for local sockets (would be listed by netstat) */
#if defined(__linux__)
f = fopen((proto==IPPROTO_TCP)?tcpfile:udpfile, "r");
if (!f) {
syslog(LOG_ERR, "cannot open %s", (proto==IPPROTO_TCP)?tcpfile:udpfile);
return -1;
}
while (fgets(line, 255, f)) {
char eaddr[68];
unsigned tmp_port;
if (sscanf(line, "%*d: %64[0-9A-Fa-f]:%x %*x:%*x %*x %*x:%*x "
"%*x:%*x %*x %*d %*d %*llu",
eaddr, &tmp_port) == 2
) {
/* TODO add IPV6 support if enabled
* Presently assumes IPV4 */
#ifdef DEBUG
syslog(LOG_DEBUG, "port_in_use check port %u and address %s", tmp_port, eaddr);
#endif
if (tmp_port == eport) {
char tmp_addr[4];
struct in_addr *tmp_ip_addr = (struct in_addr *)tmp_addr;
if (sscanf(eaddr,"%2hhx%2hhx%2hhx%2hhx",
&tmp_addr[3],&tmp_addr[2],&tmp_addr[1],&tmp_addr[0]) == 4)
{
if (tmp_ip_addr->s_addr == 0 || tmp_ip_addr->s_addr == ip_addr.s_addr)
{
found++;
break; /* don't care how many, just that we found at least one */
}
}
}
}
}
fclose(f);
#elif defined(__OpenBSD__)
static struct nlist list[] = {
#if 0
{"_tcpstat", 0, 0, 0, 0},
{"_udpstat", 0, 0, 0, 0},
{"_tcbinfo", 0, 0, 0, 0},
{"_udbinfo", 0, 0, 0, 0},
#endif
{"_tcbtable", 0, 0, 0, 0},
{"_udbtable", 0, 0, 0, 0},
{NULL,0, 0, 0, 0}
};
char errstr[_POSIX2_LINE_MAX];
kvm_t *kd;
ssize_t n;
struct inpcbtable table;
struct inpcb *next;
struct inpcb inpcb;
kd = kvm_openfiles(NULL, NULL, NULL, O_RDONLY, errstr);
if(!kd) {
syslog(LOG_ERR, "%s: kvm_openfiles(): %s",
"portinuse()", errstr);
return -1;
}
if(kvm_nlist(kd, list) < 0) {
syslog(LOG_ERR, "%s: kvm_nlist(): %s",
"portinuse()", kvm_geterr(kd));
kvm_close(kd);
return -1;
}
n = kvm_read(kd, list[(proto==IPPROTO_TCP)?0:1].n_value, &table, sizeof(table));
if(n < 0) {
syslog(LOG_ERR, "%s: kvm_read(): %s",
"portinuse()", kvm_geterr(kd));
kvm_close(kd);
return -1;
}
/* inpt_queue was CIRCLEQ_HEAD, it is TAILQ_HEAD since OpenBSD 5.5 */
#ifdef INPT_QUEUE_IS_CIRCLEQ
next = CIRCLEQ_FIRST(&table.inpt_queue);
#else
next = TAILQ_FIRST(&table.inpt_queue);
#endif
while(next != NULL) {
if(((u_long)next & 3) != 0) break;
n = kvm_read(kd, (u_long)next, &inpcb, sizeof(inpcb));
if(n < 0) {
syslog(LOG_ERR, "kvm_read(): %s", kvm_geterr(kd));
break;
}
#ifdef INPT_QUEUE_IS_CIRCLEQ
next = CIRCLEQ_NEXT(&inpcb, inp_queue);
#else
next = TAILQ_NEXT(&inpcb, inp_queue);
#endif
/* skip IPv6 sockets */
if((inpcb.inp_flags & INP_IPV6) != 0)
continue;
#ifdef DEBUG
syslog(LOG_DEBUG, "%08lx:%hu %08lx:%hu",
(u_long)inpcb.inp_laddr.s_addr, ntohs(inpcb.inp_lport),
(u_long)inpcb.inp_faddr.s_addr, ntohs(inpcb.inp_fport));
#endif
if(eport == (unsigned)ntohs(inpcb.inp_lport)) {
if(inpcb.inp_laddr.s_addr == INADDR_ANY || inpcb.inp_laddr.s_addr == ip_addr.s_addr) {
found++;
break; /* don't care how many, just that we found at least one */
}
}
}
kvm_close(kd);
#elif defined(__DragonFly__)
const char *varname;
struct xinpcb *xip;
struct xtcpcb *xtp;
struct inpcb *inp;
void *buf = NULL;
void *so_begin, *so_end;
size_t len;
switch (proto) {
case IPPROTO_TCP:
varname = "net.inet.tcp.pcblist";
break;
case IPPROTO_UDP:
varname = "net.inet.udp.pcblist";
break;
default:
syslog(LOG_ERR, "port_in_use() unknown proto=%d", proto);
return -1;
}
if (sysctlbyname(varname, NULL, &len, NULL, 0) < 0) {
syslog(LOG_ERR, "sysctlbyname(%s, NULL, ...): %m", varname);
return -1;
}
buf = malloc(len);
if (buf == NULL) {
syslog(LOG_ERR, "malloc(%u) failed", (unsigned)len);
return -1;
}
if (sysctlbyname(varname, buf, &len, NULL, 0) < 0) {
syslog(LOG_ERR, "sysctlbyname(%s, buf, ...): %m", varname);
free(buf);
return -1;
}
so_begin = buf;
so_end = (uint8_t *)buf + len;
for (so_begin = buf, so_end = (uint8_t *)so_begin + len;
(uint8_t *)so_begin + sizeof(size_t) < (uint8_t *)so_end &&
(uint8_t *)so_begin + *(size_t *)so_begin <= (uint8_t *)so_end;
so_begin = (uint8_t *)so_begin + *(size_t *)so_begin) {
switch (proto) {
case IPPROTO_TCP:
xtp = (struct xtcpcb *)so_begin;
if (xtp->xt_len != sizeof *xtp) {
syslog(LOG_WARNING, "struct xtcpcb size mismatch; %ld vs %ld",
(long)xtp->xt_len, sizeof *xtp);
free(buf);
return -1;
}
inp = &xtp->xt_inp;
break;
case IPPROTO_UDP:
xip = (struct xinpcb *)so_begin;
if (xip->xi_len != sizeof *xip) {
syslog(LOG_WARNING, "struct xinpcb size mismatch : %ld vs %ld",
(long)xip->xi_len, sizeof *xip);
free(buf);
return -1;
}
inp = &xip->xi_inp;
break;
default:
abort();
}
/* no support for IPv6 */
if (INP_ISIPV6(inp) != 0)
continue;
syslog(LOG_DEBUG, "%08lx:%hu %08lx:%hu <=> %hu %08lx:%hu",
(u_long)inp->inp_laddr.s_addr, ntohs(inp->inp_lport),
(u_long)inp->inp_faddr.s_addr, ntohs(inp->inp_fport),
eport, (u_long)ip_addr.s_addr, iport
);
if (eport == (unsigned)ntohs(inp->inp_lport)) {
if (inp->inp_laddr.s_addr == INADDR_ANY || inp->inp_laddr.s_addr == ip_addr.s_addr) {
found++;
break; /* don't care how many, just that we found at least one */
}
}
}
if (buf) {
free(buf);
buf = NULL;
}
#elif defined(__FreeBSD__)
const char *varname;
struct xinpgen *xig, *exig;
struct xinpcb *xip;
struct xtcpcb *xtp;
struct in_conninfo *inc;
void *buf = NULL;
size_t len;
switch (proto) {
case IPPROTO_TCP:
varname = "net.inet.tcp.pcblist";
break;
case IPPROTO_UDP:
varname = "net.inet.udp.pcblist";
break;
default:
syslog(LOG_ERR, "port_in_use() unknown proto=%d", proto);
return -1;
}
if (sysctlbyname(varname, NULL, &len, NULL, 0) < 0) {
syslog(LOG_ERR, "sysctlbyname(%s, NULL, ...): %m", varname);
return -1;
}
buf = malloc(len);
if (buf == NULL) {
syslog(LOG_ERR, "malloc(%u) failed", (unsigned)len);
return -1;
}
if (sysctlbyname(varname, buf, &len, NULL, 0) < 0) {
syslog(LOG_ERR, "sysctlbyname(%s, buf, ...): %m", varname);
free(buf);
return -1;
}
xig = (struct xinpgen *)buf;
exig = (struct xinpgen *)(void *)((char *)buf + len - sizeof *exig);
if (xig->xig_len != sizeof *xig) {
syslog(LOG_WARNING, "struct xinpgen size mismatch; %ld vs %ld",
(long)xig->xig_len, sizeof *xig);
free(buf);
return -1;
}
if (exig->xig_len != sizeof *exig) {
syslog(LOG_WARNING, "struct xinpgen size mismatch; %ld vs %ld",
(long)exig->xig_len, sizeof *exig);
free(buf);
return -1;
}
while (1) {
xig = (struct xinpgen *)(void *)((char *)xig + xig->xig_len);
if (xig >= exig)
break;
switch (proto) {
case IPPROTO_TCP:
xtp = (struct xtcpcb *)xig;
if (xtp->xt_len != sizeof *xtp) {
syslog(LOG_WARNING, "struct xtcpcb size mismatch; %ld vs %ld",
(long)xtp->xt_len, sizeof *xtp);
free(buf);
return -1;
}
xip = &xtp->xt_inp;
inc = &xip->inp_inc;
break;
case IPPROTO_UDP:
xip = (struct xinpcb *)xig;
if (xip->xi_len != sizeof *xip) {
syslog(LOG_WARNING, "struct xinpcb size mismatch : %ld vs %ld",
(long)xip->xi_len, sizeof *xip);
free(buf);
return -1;
}
inc = &xip->inp_inc;
break;
default:
abort();
}
/* no support for IPv6 */
if ((xip->inp_vflag & INP_IPV6) != 0)
continue;
syslog(LOG_DEBUG, "%08lx:%hu %08lx:%hu <=> %hu %08lx:%hu",
(u_long)inc->inc_laddr.s_addr, ntohs(inc->inc_lport),
(u_long)inc->inc_faddr.s_addr, ntohs(inc->inc_fport),
eport, (u_long)ip_addr.s_addr, iport
);
if (eport == (unsigned)ntohs(inc->inc_lport)) {
if (inc->inc_laddr.s_addr == INADDR_ANY || inc->inc_laddr.s_addr == ip_addr.s_addr) {
found++;
break; /* don't care how many, just that we found at least one */
}
}
}
if (buf) {
free(buf);
buf = NULL;
}
/* #elif __NetBSD__ */
#else
/* TODO : NetBSD / Darwin (OS X) / Solaris code */
#error "No port_in_use() implementation available for this OS"
#endif
/* Phase 2 : check existing mappings
* TODO : implement for pf/ipfw/etc. */
#if defined(USE_NETFILTER)
if (!found) {
char iaddr_old[16];
unsigned short iport_old;
int i;
for (i = 0; chains_to_check[i]; i++) {
if (get_nat_redirect_rule(chains_to_check[i], if_name, eport, proto,
iaddr_old, sizeof(iaddr_old), &iport_old,
0, 0, 0, 0, 0, 0, 0) == 0)
{
syslog(LOG_DEBUG, "port_in_use check port %d on nat chain %s redirected to %s port %d", eport,
chains_to_check[i], iaddr_old, iport_old);
if (!(strcmp(iaddr, iaddr_old)==0 && iport==iport_old)) {
/* only "in use" if redirected to somewhere else */
found++;
break; /* don't care how many, just that we found at least one */
}
}
}
}
#else /* USE_NETFILTER */
UNUSED(iport); UNUSED(iaddr);
#endif /* USE_NETFILTER */
return found;
}
#endif /* CHECK_PORTINUSE */