freebsd-dev/usr.sbin/ppp/main.c
Brian Somers 6f38457323 o Create a new `timer'' log level. This lets us `set
log debug'' without filling our filesystem/screen with
  junk that we don't really want to see.
o change PHYS_STDIN to PHYS_DIRECT - we can handle incoming
  connections that aren't on STDIN_FILENO now.
o Allow return values from our FSM LayerUp functions.  If
  LayerUp() fails, the FSM does an immediate FsmDown() without
  calling the fsm_parent's Layer{Up,Down} functions.
o Clear the close-on-exec flag of file descriptor 3 when executing
  chat programs so that our documented ability to communicate with
  /dev/tty via that descriptor works.  Also document it as
  descriptor 3, not 4 :-O
o Allow a ``rm'' command as an alias for ``remove''.
o Fix the bind()/connect()/accept() calls made by the MP server.
o Create bundle_SendDatalink() and bundle_ReceiveDatalink().
  This allows `struct datalink's to flatten themselves, pass
  through a pipe (read: the eye of a needle !) and come alive
  at the other end.  The donator then fork()s & exec()s pppmpipe,
  ``passing'' the connection to another ppp instance.

   *** PPP NOW TALKS MULTILINK :-))) ***

Our link utilization is hideous, and lots of code needs
tidying still.  It's also probably riddled with bugs !
It's been tested against itself only, and has hung once,
so confidence isn't high....
1998-04-30 23:53:56 +00:00

625 lines
16 KiB
C

/*
* User Process PPP
*
* Written by Toshiharu OHNO (tony-o@iij.ad.jp)
*
* Copyright (C) 1993, Internet Initiative Japan, Inc. All rights reserverd.
*
* Redistribution and use in source and binary forms are permitted
* provided that the above copyright notice and this paragraph are
* duplicated in all such forms and that any documentation,
* advertising materials, and other materials related to such
* distribution and use acknowledge that the software was developed
* by the Internet Initiative Japan, Inc. The name of the
* IIJ may not be used to endorse or promote products derived
* from this software without specific prior written permission.
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
* WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*
* $Id: main.c,v 1.121.2.52 1998/04/28 01:25:30 brian Exp $
*
* TODO:
*/
#include <sys/param.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <sys/un.h>
#include <net/if_tun.h>
#include <errno.h>
#include <fcntl.h>
#include <paths.h>
#include <signal.h>
#include <stdio.h>
#include <string.h>
#include <termios.h>
#include <unistd.h>
#include "mbuf.h"
#include "log.h"
#include "defs.h"
#include "id.h"
#include "timer.h"
#include "fsm.h"
#include "lqr.h"
#include "hdlc.h"
#include "lcp.h"
#include "ccp.h"
#include "iplist.h"
#include "throughput.h"
#include "slcompress.h"
#include "ipcp.h"
#include "filter.h"
#include "descriptor.h"
#include "link.h"
#include "mp.h"
#include "bundle.h"
#include "loadalias.h"
#include "auth.h"
#include "systems.h"
#include "ip.h"
#include "sig.h"
#include "main.h"
#include "pathnames.h"
#include "tun.h"
#include "server.h"
#include "prompt.h"
#include "chat.h"
#include "chap.h"
#include "datalink.h"
#ifndef O_NONBLOCK
#ifdef O_NDELAY
#define O_NONBLOCK O_NDELAY
#endif
#endif
static char pid_filename[MAXPATHLEN];
static void DoLoop(struct bundle *, struct prompt *);
static void TerminalStop(int);
static const char *ex_desc(int);
static struct bundle *SignalBundle;
static struct prompt *SignalPrompt;
void
Cleanup(int excode)
{
SignalBundle->CleaningUp = 1;
if (bundle_Phase(SignalBundle) != PHASE_DEAD)
bundle_Close(SignalBundle, NULL, 1);
}
void
AbortProgram(int excode)
{
ServerClose(SignalBundle);
ID0unlink(pid_filename);
LogPrintf(LogPHASE, "PPP Terminated (%s).\n", ex_desc(excode));
bundle_Close(SignalBundle, NULL, 1);
bundle_Destroy(SignalBundle);
LogClose();
exit(excode);
}
static void
CloseConnection(int signo)
{
/* NOTE, these are manual, we've done a setsid() */
struct datalink *dl;
pending_signal(SIGINT, SIG_IGN);
LogPrintf(LogPHASE, "Caught signal %d, abort connection(s)\n", signo);
for (dl = SignalBundle->links; dl; dl = dl->next)
datalink_Down(dl, 1);
pending_signal(SIGINT, CloseConnection);
}
static void
CloseSession(int signo)
{
LogPrintf(LogPHASE, "Signal %d, terminate.\n", signo);
Cleanup(EX_TERM);
}
static pid_t BGPid = 0;
static void
KillChild(int signo)
{
LogPrintf(LogPHASE, "Parent: Signal %d\n", signo);
kill(BGPid, SIGINT);
}
static void
TerminalCont(int signo)
{
signal(SIGCONT, SIG_DFL);
prompt_Continue(SignalPrompt);
}
static void
TerminalStop(int signo)
{
prompt_Suspend(SignalPrompt);
signal(SIGCONT, TerminalCont);
raise(SIGSTOP);
}
#if 0 /* What's our passwd :-O */
static void
SetUpServer(int signo)
{
int res;
VarHaveLocalAuthKey = 0;
LocalAuthInit();
if ((res = ServerTcpOpen(SERVER_PORT + SignalBundle->unit)) != 0)
LogPrintf(LogERROR, "SIGUSR1: Failed %d to open port %d\n",
res, SERVER_PORT + SignalBundle->unit);
}
#endif
static void
BringDownServer(int signo)
{
/* Drops all child prompts too ! */
ServerClose(SignalBundle);
}
static const char *
ex_desc(int ex)
{
static char num[12];
static const char *desc[] = {
"normal", "start", "sock", "modem", "dial", "dead", "done",
"reboot", "errdead", "hangup", "term", "nodial", "nologin"
};
if (ex >= 0 && ex < sizeof desc / sizeof *desc)
return desc[ex];
snprintf(num, sizeof num, "%d", ex);
return num;
}
static void
Usage(void)
{
fprintf(stderr,
"Usage: ppp [-auto | -background | -direct | -dedicated | -ddial ]"
#ifndef NOALIAS
" [ -alias ]"
#endif
" [system]\n");
exit(EX_START);
}
static char *
ProcessArgs(int argc, char **argv, int *mode)
{
int optc, labelrequired;
char *cp;
optc = labelrequired = 0;
*mode = PHYS_MANUAL;
while (argc > 0 && **argv == '-') {
cp = *argv + 1;
if (strcmp(cp, "auto") == 0) {
*mode = PHYS_DEMAND;
labelrequired = 1;
} else if (strcmp(cp, "background") == 0) {
*mode = PHYS_1OFF;
labelrequired = 1;
} else if (strcmp(cp, "direct") == 0)
*mode = PHYS_DIRECT;
else if (strcmp(cp, "dedicated") == 0)
*mode = PHYS_DEDICATED;
else if (strcmp(cp, "ddial") == 0) {
*mode = PHYS_PERM;
labelrequired = 1;
} else if (strcmp(cp, "alias") == 0) {
#ifndef NOALIAS
if (loadAliasHandlers() != 0)
#endif
LogPrintf(LogWARN, "Cannot load alias library\n");
optc--; /* this option isn't exclusive */
} else
Usage();
optc++;
argv++;
argc--;
}
if (argc > 1) {
fprintf(stderr, "You may specify only one system label.\n");
exit(EX_START);
}
if (optc > 1) {
fprintf(stderr, "You may specify only one mode.\n");
exit(EX_START);
}
if (labelrequired && argc != 1) {
fprintf(stderr, "Destination system must be specified in"
" auto, background or ddial mode.\n");
exit(EX_START);
}
return argc == 1 ? *argv : NULL; /* Don't SetLabel yet ! */
}
int
main(int argc, char **argv)
{
FILE *lockfile;
char *name, *label;
int nfds, mode;
struct bundle *bundle;
struct prompt *prompt;
nfds = getdtablesize();
if (nfds >= FD_SETSIZE)
/*
* If we've got loads of file descriptors, make sure they're all
* closed. If they aren't, we may end up with a seg fault when our
* `fd_set's get too big when select()ing !
*/
while (--nfds > 2)
close(nfds);
name = strrchr(argv[0], '/');
LogOpen(name ? name + 1 : argv[0]);
argc--;
argv++;
label = ProcessArgs(argc, argv, &mode);
#ifdef __FreeBSD__
/*
* A FreeBSD hack to dodge a bug in the tty driver that drops output
* occasionally.... I must find the real reason some time. To display
* the dodgy behaviour, comment out this bit, make yourself a large
* routing table and then run ppp in interactive mode. The `show route'
* command will drop chunks of data !!!
*/
if (mode == PHYS_MANUAL) {
close(STDIN_FILENO);
if (open(_PATH_TTY, O_RDONLY) != STDIN_FILENO) {
fprintf(stderr, "Cannot open %s for input !\n", _PATH_TTY);
return 2;
}
}
#endif
/* Allow output for the moment (except in direct mode) */
if (mode == PHYS_DIRECT)
prompt = NULL;
else {
const char *m;
SignalPrompt = prompt = prompt_Create(NULL, NULL, PROMPT_STD);
if (mode == PHYS_PERM)
m = "direct dial";
else if (mode & PHYS_1OFF)
m = "background";
else if (mode & PHYS_DEMAND)
m = "auto";
else if (mode & PHYS_DEDICATED)
m = "dedicated";
else if (mode & PHYS_MANUAL)
m = "interactive";
else
m = NULL;
if (m)
prompt_Printf(prompt, "Working in %s mode\n", m);
}
ID0init();
if (ID0realuid() != 0) {
char conf[200], *ptr;
snprintf(conf, sizeof conf, "%s/%s", _PATH_PPP, CONFFILE);
do {
if (!access(conf, W_OK)) {
LogPrintf(LogALERT, "ppp: Access violation: Please protect %s\n", conf);
return -1;
}
ptr = conf + strlen(conf)-2;
while (ptr > conf && *ptr != '/')
*ptr-- = '\0';
} while (ptr >= conf);
}
if (!ValidSystem(label, prompt, mode)) {
fprintf(stderr, "You may not use ppp in this mode with this label\n");
if (mode == PHYS_DIRECT) {
const char *l;
l = label ? label : "default";
LogPrintf(LogWARN, "Label %s rejected -direct connection\n", l);
}
LogClose();
return 1;
}
if ((bundle = bundle_Create(TUN_PREFIX, prompt, mode)) == NULL) {
LogPrintf(LogWARN, "bundle_Create: %s\n", strerror(errno));
return EX_START;
}
SignalBundle = bundle;
if (SelectSystem(bundle, "default", CONFFILE, prompt) < 0)
prompt_Printf(prompt, "Warning: No default entry found in config file.\n");
pending_signal(SIGHUP, CloseSession);
pending_signal(SIGTERM, CloseSession);
pending_signal(SIGINT, CloseConnection);
pending_signal(SIGQUIT, CloseSession);
pending_signal(SIGALRM, SIG_IGN);
signal(SIGPIPE, SIG_IGN);
if (mode == PHYS_MANUAL)
pending_signal(SIGTSTP, TerminalStop);
#if 0 /* What's our passwd :-O */
pending_signal(SIGUSR1, SetUpServer);
#endif
pending_signal(SIGUSR2, BringDownServer);
if (label) {
/*
* Set label both before and after SelectSystem !
* This way, "set enddisc label" works during SelectSystem, and we
* also end up with the correct label if we have embedded load
* commands.
*/
bundle_SetLabel(bundle, label);
if (SelectSystem(bundle, label, CONFFILE, prompt) < 0) {
prompt_Printf(prompt, "Destination system (%s) not found.\n", label);
AbortProgram(EX_START);
}
bundle_SetLabel(bundle, label);
if (mode == PHYS_DEMAND &&
bundle->ncp.ipcp.cfg.peer_range.ipaddr.s_addr == INADDR_ANY) {
prompt_Printf(prompt, "You must \"set ifaddr\" with a peer address "
"in label %s for auto mode.\n", label);
AbortProgram(EX_START);
}
}
if (mode != PHYS_MANUAL) {
if (mode != PHYS_DIRECT) {
int bgpipe[2];
pid_t bgpid;
if (mode == PHYS_1OFF && pipe(bgpipe)) {
LogPrintf(LogERROR, "pipe: %s\n", strerror(errno));
AbortProgram(EX_SOCK);
}
bgpid = fork();
if (bgpid == -1) {
LogPrintf(LogERROR, "fork: %s\n", strerror(errno));
AbortProgram(EX_SOCK);
}
if (bgpid) {
char c = EX_NORMAL;
if (mode == PHYS_1OFF) {
close(bgpipe[1]);
BGPid = bgpid;
/* If we get a signal, kill the child */
signal(SIGHUP, KillChild);
signal(SIGTERM, KillChild);
signal(SIGINT, KillChild);
signal(SIGQUIT, KillChild);
/* Wait for our child to close its pipe before we exit */
if (read(bgpipe[0], &c, 1) != 1) {
prompt_Printf(prompt, "Child exit, no status.\n");
LogPrintf(LogPHASE, "Parent: Child exit, no status.\n");
} else if (c == EX_NORMAL) {
prompt_Printf(prompt, "PPP enabled.\n");
LogPrintf(LogPHASE, "Parent: PPP enabled.\n");
} else {
prompt_Printf(prompt, "Child failed (%s).\n", ex_desc((int) c));
LogPrintf(LogPHASE, "Parent: Child failed (%s).\n",
ex_desc((int) c));
}
close(bgpipe[0]);
}
return c;
} else if (mode == PHYS_1OFF) {
close(bgpipe[0]);
bundle->notify.fd = bgpipe[1];
}
/* -auto, -dedicated, -ddial & -background */
prompt_Destroy(prompt, 0);
close(STDOUT_FILENO);
close(STDERR_FILENO);
close(STDIN_FILENO);
setsid();
} else {
/* -direct: STDIN_FILENO gets used by modem_Open */
prompt_TtyInit(NULL);
close(STDOUT_FILENO);
close(STDERR_FILENO);
}
} else {
/* Interactive mode */
close(STDERR_FILENO);
prompt_TtyInit(prompt);
prompt_TtyCommandMode(prompt);
prompt_Required(prompt);
}
snprintf(pid_filename, sizeof pid_filename, "%stun%d.pid",
_PATH_VARRUN, bundle->unit);
lockfile = ID0fopen(pid_filename, "w");
if (lockfile != NULL) {
fprintf(lockfile, "%d\n", (int) getpid());
fclose(lockfile);
}
#ifndef RELEASE_CRUNCH
else
LogPrintf(LogALERT, "Warning: Can't create %s: %s\n",
pid_filename, strerror(errno));
#endif
LogPrintf(LogPHASE, "PPP Started (%s mode).\n", mode2Nam(mode));
DoLoop(bundle, prompt);
AbortProgram(EX_NORMAL);
return EX_NORMAL;
}
static void
DoLoop(struct bundle *bundle, struct prompt *prompt)
{
fd_set rfds, wfds, efds;
int pri, i, n, nfds;
int qlen;
struct tun_data tun;
do {
nfds = 0;
FD_ZERO(&rfds);
FD_ZERO(&wfds);
FD_ZERO(&efds);
qlen = bundle_FillQueues(bundle);
handle_signals();
/* This one comes first 'cos it may nuke a datalink */
descriptor_UpdateSet(&bundle->ncp.mp.server.desc, &rfds, &wfds,
&efds, &nfds);
descriptor_UpdateSet(&bundle->desc, &rfds, &wfds, &efds, &nfds);
descriptor_UpdateSet(&server.desc, &rfds, &wfds, &efds, &nfds);
/* If there are aren't many packets queued, look for some more. */
if (qlen < 20 && bundle->tun_fd >= 0) {
if (bundle->tun_fd + 1 > nfds)
nfds = bundle->tun_fd + 1;
FD_SET(bundle->tun_fd, &rfds);
}
if (bundle_IsDead(bundle))
/* Don't select - we'll be here forever */
break;
i = select(nfds, &rfds, &wfds, &efds, NULL);
if (i == 0)
continue;
if (i < 0) {
if (errno == EINTR) {
handle_signals();
continue;
}
LogPrintf(LogERROR, "DoLoop: select(): %s\n", strerror(errno));
break;
}
for (i = 0; i <= nfds; i++)
if (FD_ISSET(i, &efds)) {
LogPrintf(LogALERT, "Exception detected on descriptor %d\n", i);
break;
}
if (descriptor_IsSet(&bundle->ncp.mp.server.desc, &rfds))
descriptor_Read(&bundle->ncp.mp.server.desc, bundle, &rfds);
if (descriptor_IsSet(&server.desc, &rfds))
descriptor_Read(&server.desc, bundle, &rfds);
if (descriptor_IsSet(&bundle->desc, &wfds))
descriptor_Write(&bundle->desc, bundle, &wfds);
if (descriptor_IsSet(&bundle->desc, &rfds))
descriptor_Read(&bundle->desc, bundle, &rfds);
if (bundle->tun_fd >= 0 && FD_ISSET(bundle->tun_fd, &rfds)) {
/* something to read from tun */
n = read(bundle->tun_fd, &tun, sizeof tun);
if (n < 0) {
LogPrintf(LogERROR, "read from tun: %s\n", strerror(errno));
continue;
}
n -= sizeof tun - sizeof tun.data;
if (n <= 0) {
LogPrintf(LogERROR, "read from tun: Only %d bytes read\n", n);
continue;
}
if (!tun_check_header(tun, AF_INET))
continue;
if (((struct ip *)tun.data)->ip_dst.s_addr ==
bundle->ncp.ipcp.my_ip.s_addr) {
/* we've been asked to send something addressed *to* us :( */
if (Enabled(bundle, OPT_LOOPBACK)) {
pri = PacketCheck(bundle, tun.data, n, &bundle->filter.in);
if (pri >= 0) {
struct mbuf *bp;
#ifndef NOALIAS
if (AliasEnabled()) {
(*PacketAlias.In)(tun.data, sizeof tun.data);
n = ntohs(((struct ip *)tun.data)->ip_len);
}
#endif
bp = mballoc(n, MB_IPIN);
memcpy(MBUF_CTOP(bp), tun.data, n);
IpInput(bundle, bp);
LogPrintf(LogDEBUG, "Looped back packet addressed to myself\n");
}
continue;
} else
LogPrintf(LogDEBUG, "Oops - forwarding packet addressed to myself\n");
}
/*
* Process on-demand dialup. Output packets are queued within tunnel
* device until IPCP is opened.
*/
if (bundle_Phase(bundle) == PHASE_DEAD) {
/*
* Note, we must be in AUTO mode :-/ otherwise our interface should
* *not* be UP and we can't receive data
*/
if ((pri = PacketCheck(bundle, tun.data, n, &bundle->filter.dial)) >= 0)
bundle_Open(bundle, NULL, PHYS_DEMAND);
else
/*
* Drop the packet. If we were to queue it, we'd just end up with
* a pile of timed-out data in our output queue by the time we get
* around to actually dialing. We'd also prematurely reach the
* threshold at which we stop select()ing to read() the tun
* device - breaking auto-dial.
*/
continue;
}
pri = PacketCheck(bundle, tun.data, n, &bundle->filter.out);
if (pri >= 0) {
#ifndef NOALIAS
if (AliasEnabled()) {
(*PacketAlias.Out)(tun.data, sizeof tun.data);
n = ntohs(((struct ip *)tun.data)->ip_len);
}
#endif
IpEnqueue(pri, tun.data, n);
}
}
} while (bundle_CleanDatalinks(bundle), !bundle_IsDead(bundle));
LogPrintf(LogDEBUG, "DoLoop done.\n");
}