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4562be7470
freebsd/usr.sbin/ppp/main.c
Brian Somers 4562be7470 Don't run if ppp.conf is writable.
1997-11-13 15:35:06 +00:00

1061 lines
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/*
* 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 1.97 1997/11/13 14:44:06 brian Exp $
*
* TODO:
* o Add commands for traffic summary, version display, etc.
* o Add signal handler for misc controls.
*/
#include <sys/param.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <errno.h>
#include <fcntl.h>
#include <paths.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/time.h>
#include <sys/wait.h>
#include <sysexits.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 "modem.h"
#include "os.h"
#include "hdlc.h"
#include "ccp.h"
#include "lcp.h"
#include "ipcp.h"
#include "loadalias.h"
#include "command.h"
#include "vars.h"
#include "auth.h"
#include "filter.h"
#include "systems.h"
#include "ip.h"
#include "sig.h"
#include "server.h"
#include "lcpproto.h"
#include "main.h"
#include "vjcomp.h"
#include "async.h"
#include "pathnames.h"
#ifndef O_NONBLOCK
#ifdef O_NDELAY
#define O_NONBLOCK O_NDELAY
#endif
#endif
int TermMode = 0;
int tunno = 0;
static struct termios oldtio; /* Original tty mode */
static struct termios comtio; /* Command level tty mode */
static pid_t BGPid = 0;
static char pid_filename[MAXPATHLEN];
static int dial_up;
static void DoLoop(void);
static void TerminalStop(int);
static char *ex_desc(int);
static void
TtyInit(int DontWantInt)
{
struct termios newtio;
int stat;
stat = fcntl(0, F_GETFL, 0);
if (stat > 0) {
stat |= O_NONBLOCK;
(void) fcntl(0, F_SETFL, stat);
}
newtio = oldtio;
newtio.c_lflag &= ~(ECHO | ISIG | ICANON);
newtio.c_iflag = 0;
newtio.c_oflag &= ~OPOST;
newtio.c_cc[VEOF] = _POSIX_VDISABLE;
if (DontWantInt)
newtio.c_cc[VINTR] = _POSIX_VDISABLE;
newtio.c_cc[VMIN] = 1;
newtio.c_cc[VTIME] = 0;
newtio.c_cflag |= CS8;
tcsetattr(0, TCSADRAIN, &newtio);
comtio = newtio;
}
/*
* Set tty into command mode. We allow canonical input and echo processing.
*/
void
TtyCommandMode(int prompt)
{
struct termios newtio;
int stat;
if (!(mode & MODE_INTER))
return;
tcgetattr(0, &newtio);
newtio.c_lflag |= (ECHO | ISIG | ICANON);
newtio.c_iflag = oldtio.c_iflag;
newtio.c_oflag |= OPOST;
tcsetattr(0, TCSADRAIN, &newtio);
stat = fcntl(0, F_GETFL, 0);
if (stat > 0) {
stat |= O_NONBLOCK;
(void) fcntl(0, F_SETFL, stat);
}
TermMode = 0;
if (prompt)
Prompt();
}
/*
* Set tty into terminal mode which is used while we invoke term command.
*/
void
TtyTermMode()
{
int stat;
tcsetattr(0, TCSADRAIN, &comtio);
stat = fcntl(0, F_GETFL, 0);
if (stat > 0) {
stat &= ~O_NONBLOCK;
(void) fcntl(0, F_SETFL, stat);
}
TermMode = 1;
}
void
TtyOldMode()
{
int stat;
stat = fcntl(0, F_GETFL, 0);
if (stat > 0) {
stat &= ~O_NONBLOCK;
(void) fcntl(0, F_SETFL, stat);
}
tcsetattr(0, TCSANOW, &oldtio);
}
void
Cleanup(int excode)
{
ServerClose();
OsInterfaceDown(1);
HangupModem(1);
nointr_sleep(1);
DeleteIfRoutes(1);
ID0unlink(pid_filename);
if (mode & MODE_BACKGROUND && BGFiledes[1] != -1) {
char c = EX_ERRDEAD;
if (write(BGFiledes[1], &c, 1) == 1)
LogPrintf(LogPHASE, "Parent notified of failure.\n");
else
LogPrintf(LogPHASE, "Failed to notify parent of failure.\n");
close(BGFiledes[1]);
}
LogPrintf(LogPHASE, "PPP Terminated (%s).\n", ex_desc(excode));
TtyOldMode();
LogClose();
exit(excode);
}
static void
CloseConnection(int signo)
{
/* NOTE, these are manual, we've done a setsid() */
pending_signal(SIGINT, SIG_IGN);
LogPrintf(LogPHASE, "Caught signal %d, abort connection\n", signo);
reconnectState = RECON_FALSE;
reconnectCount = 0;
DownConnection();
dial_up = 0;
pending_signal(SIGINT, CloseConnection);
}
static void
CloseSession(int signo)
{
if (BGPid) {
kill(BGPid, SIGINT);
exit(EX_TERM);
}
LogPrintf(LogPHASE, "Signal %d, terminate.\n", signo);
reconnect(RECON_FALSE);
LcpClose();
Cleanup(EX_TERM);
}
static void
TerminalCont()
{
pending_signal(SIGCONT, SIG_DFL);
pending_signal(SIGTSTP, TerminalStop);
TtyCommandMode(getpgrp() == tcgetpgrp(0));
}
static void
TerminalStop(int signo)
{
pending_signal(SIGCONT, TerminalCont);
TtyOldMode();
pending_signal(SIGTSTP, SIG_DFL);
kill(getpid(), signo);
}
static void
SetUpServer(int signo)
{
int res;
VarHaveLocalAuthKey = 0;
LocalAuthInit();
if ((res = ServerTcpOpen(SERVER_PORT + tunno)) != 0)
LogPrintf(LogERROR, "SIGUSR1: Failed %d to open port %d\n",
res, SERVER_PORT + tunno);
}
static void
BringDownServer(int signo)
{
VarHaveLocalAuthKey = 0;
LocalAuthInit();
ServerClose();
}
static char *
ex_desc(int ex)
{
static char num[12];
static 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()
{
fprintf(stderr,
"Usage: ppp [-auto | -background | -direct | -dedicated | -ddial ] [ -alias ] [system]\n");
exit(EX_START);
}
static void
ProcessArgs(int argc, char **argv)
{
int optc;
char *cp;
optc = 0;
mode = MODE_INTER;
while (argc > 0 && **argv == '-') {
cp = *argv + 1;
if (strcmp(cp, "auto") == 0) {
mode |= MODE_AUTO;
mode &= ~MODE_INTER;
} else if (strcmp(cp, "background") == 0) {
mode |= MODE_BACKGROUND;
mode &= ~MODE_INTER;
} else if (strcmp(cp, "direct") == 0) {
mode |= MODE_DIRECT;
mode &= ~MODE_INTER;
} else if (strcmp(cp, "dedicated") == 0) {
mode |= MODE_DEDICATED;
mode &= ~MODE_INTER;
} else if (strcmp(cp, "ddial") == 0) {
mode |= MODE_DDIAL;
mode &= ~MODE_INTER;
} else if (strcmp(cp, "alias") == 0) {
if (loadAliasHandlers(&VarAliasHandlers) == 0)
mode |= MODE_ALIAS;
else
LogPrintf(LogWARN, "Cannot load alias library\n");
optc--; /* this option isn't exclusive */
} else
Usage();
optc++;
argv++;
argc--;
}
if (argc > 1) {
fprintf(stderr, "specify only one system label.\n");
exit(EX_START);
}
if (argc == 1)
SetLabel(*argv);
if (optc > 1) {
fprintf(stderr, "specify only one mode.\n");
exit(EX_START);
}
}
static void
Greetings()
{
if (VarTerm) {
fprintf(VarTerm, "User Process PPP. Written by Toshiharu OHNO.\n");
fflush(VarTerm);
}
}
int
main(int argc, char **argv)
{
FILE *lockfile;
char *name;
VarTerm = 0;
name = strrchr(argv[0], '/');
LogOpen(name ? name + 1 : argv[0]);
argc--;
argv++;
ProcessArgs(argc, argv);
if (!(mode & MODE_DIRECT))
VarTerm = stdout;
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(GetLabel())) {
fprintf(stderr, "You may not use ppp in this mode with this label\n");
if (mode & MODE_DIRECT) {
const char *l;
if ((l = GetLabel()) == NULL)
l = "default";
VarTerm = 0;
LogPrintf(LogWARN, "Label %s rejected -direct connection\n", l);
}
LogClose();
return 1;
}
Greetings();
IpcpDefAddress();
LocalAuthInit();
if (SelectSystem("default", CONFFILE) < 0 && VarTerm)
fprintf(VarTerm, "Warning: No default entry is given in config file.\n");
if (OpenTunnel(&tunno) < 0) {
LogPrintf(LogWARN, "open_tun: %s\n", strerror(errno));
return EX_START;
}
if (mode & MODE_INTER) {
fprintf(VarTerm, "Interactive mode\n");
netfd = STDOUT_FILENO;
} else if ((mode & MODE_OUTGOING_DAEMON) && !(mode & MODE_DEDICATED))
if (GetLabel() == NULL) {
if (VarTerm)
fprintf(VarTerm, "Destination system must be specified in"
" auto, background or ddial mode.\n");
return EX_START;
}
tcgetattr(0, &oldtio); /* Save original tty mode */
pending_signal(SIGHUP, CloseSession);
pending_signal(SIGTERM, CloseSession);
pending_signal(SIGINT, CloseConnection);
pending_signal(SIGQUIT, CloseSession);
#ifdef SIGPIPE
signal(SIGPIPE, SIG_IGN);
#endif
#ifdef SIGALRM
pending_signal(SIGALRM, SIG_IGN);
#endif
if (mode & MODE_INTER) {
#ifdef SIGTSTP
pending_signal(SIGTSTP, TerminalStop);
#endif
#ifdef SIGTTIN
pending_signal(SIGTTIN, TerminalStop);
#endif
#ifdef SIGTTOU
pending_signal(SIGTTOU, SIG_IGN);
#endif
}
if (!(mode & MODE_INTER)) {
#ifdef SIGUSR1
pending_signal(SIGUSR1, SetUpServer);
#endif
#ifdef SIGUSR2
pending_signal(SIGUSR2, BringDownServer);
#endif
}
if (GetLabel()) {
if (SelectSystem(GetLabel(), CONFFILE) < 0) {
LogPrintf(LogWARN, "Destination system %s not found in conf file.\n",
GetLabel());
Cleanup(EX_START);
}
if (mode & MODE_OUTGOING_DAEMON &&
DefHisAddress.ipaddr.s_addr == INADDR_ANY) {
LogPrintf(LogWARN, "You must \"set ifaddr\" in label %s for"
" auto, background or ddial mode.\n", GetLabel());
Cleanup(EX_START);
}
}
if (mode & MODE_DAEMON) {
if (mode & MODE_BACKGROUND) {
if (pipe(BGFiledes)) {
LogPrintf(LogERROR, "pipe: %s\n", strerror(errno));
Cleanup(EX_SOCK);
}
}
if (!(mode & MODE_DIRECT)) {
pid_t bgpid;
bgpid = fork();
if (bgpid == -1) {
LogPrintf(LogERROR, "fork: %s\n", strerror(errno));
Cleanup(EX_SOCK);
}
if (bgpid) {
char c = EX_NORMAL;
if (mode & MODE_BACKGROUND) {
/* Wait for our child to close its pipe before we exit. */
BGPid = bgpid;
close(BGFiledes[1]);
if (read(BGFiledes[0], &c, 1) != 1) {
fprintf(VarTerm, "Child exit, no status.\n");
LogPrintf(LogPHASE, "Parent: Child exit, no status.\n");
} else if (c == EX_NORMAL) {
fprintf(VarTerm, "PPP enabled.\n");
LogPrintf(LogPHASE, "Parent: PPP enabled.\n");
} else {
fprintf(VarTerm, "Child failed (%s).\n", ex_desc((int) c));
LogPrintf(LogPHASE, "Parent: Child failed (%s).\n",
ex_desc((int) c));
}
close(BGFiledes[0]);
}
return c;
} else if (mode & MODE_BACKGROUND)
close(BGFiledes[0]);
}
VarTerm = 0; /* We know it's currently stdout */
close(1);
close(2);
if (mode & MODE_DIRECT)
TtyInit(1);
else if (mode & MODE_DAEMON) {
setsid();
close(0);
}
} else {
TtyInit(0);
TtyCommandMode(1);
}
snprintf(pid_filename, sizeof(pid_filename), "%stun%d.pid",
_PATH_VARRUN, tunno);
lockfile = ID0fopen(pid_filename, "w");
if (lockfile != NULL) {
fprintf(lockfile, "%d\n", (int) getpid());
fclose(lockfile);
} else
LogPrintf(LogALERT, "Warning: Can't create %s: %s\n",
pid_filename, strerror(errno));
LogPrintf(LogPHASE, "PPP Started.\n");
do
DoLoop();
while (mode & MODE_DEDICATED);
Cleanup(EX_DONE);
return 0;
}
/*
* Turn into packet mode, where we speak PPP.
*/
void
PacketMode()
{
if (RawModem() < 0) {
LogPrintf(LogWARN, "PacketMode: Not connected.\n");
return;
}
AsyncInit();
VjInit(15);
LcpInit();
IpcpInit();
CcpInit();
LcpUp();
LcpOpen(VarOpenMode);
if (mode & MODE_INTER)
TtyCommandMode(1);
if (VarTerm) {
fprintf(VarTerm, "Packet mode.\n");
aft_cmd = 1;
}
}
static void
ShowHelp()
{
fprintf(stderr, "The following commands are available:\r\n");
fprintf(stderr, " ~p\tEnter Packet mode\r\n");
fprintf(stderr, " ~-\tDecrease log level\r\n");
fprintf(stderr, " ~+\tIncrease log level\r\n");
fprintf(stderr, " ~t\tShow timers (only in \"log debug\" mode)\r\n");
fprintf(stderr, " ~m\tShow memory map (only in \"log debug\" mode)\r\n");
fprintf(stderr, " ~.\tTerminate program\r\n");
fprintf(stderr, " ~?\tThis help\r\n");
}
static void
ReadTty()
{
int n;
char ch;
static int ttystate;
FILE *oVarTerm;
char linebuff[LINE_LEN];
LogPrintf(LogDEBUG, "termode = %d, netfd = %d, mode = %d\n",
TermMode, netfd, mode);
if (!TermMode) {
n = read(netfd, linebuff, sizeof(linebuff) - 1);
if (n > 0) {
aft_cmd = 1;
if (linebuff[n-1] == '\n')
linebuff[--n] = '\0';
if (n)
DecodeCommand(linebuff, n, IsInteractive(0) ? NULL : "Client");
Prompt();
} else {
LogPrintf(LogPHASE, "client connection closed.\n");
oVarTerm = VarTerm;
VarTerm = 0;
if (oVarTerm && oVarTerm != stdout)
fclose(oVarTerm);
close(netfd);
netfd = -1;
}
return;
}
/*
* We are in terminal mode, decode special sequences
*/
n = read(fileno(VarTerm), &ch, 1);
LogPrintf(LogDEBUG, "Got %d bytes (reading from the terminal)\n", n);
if (n > 0) {
switch (ttystate) {
case 0:
if (ch == '~')
ttystate++;
else
write(modem, &ch, n);
break;
case 1:
switch (ch) {
case '?':
ShowHelp();
break;
case 'p':
/*
* XXX: Should check carrier.
*/
if (LcpFsm.state <= ST_CLOSED) {
VarOpenMode = OPEN_ACTIVE;
PacketMode();
}
break;
case '.':
TermMode = 1;
aft_cmd = 1;
TtyCommandMode(1);
break;
case 't':
if (LogIsKept(LogDEBUG)) {
ShowTimers();
break;
}
case 'm':
if (LogIsKept(LogDEBUG)) {
ShowMemMap();
break;
}
default:
if (write(modem, &ch, n) < 0)
LogPrintf(LogERROR, "error writing to modem.\n");
break;
}
ttystate = 0;
break;
}
}
}
/*
* Here, we'll try to detect HDLC frame
*/
static char *FrameHeaders[] = {
"\176\377\003\300\041",
"\176\377\175\043\300\041",
"\176\177\175\043\100\041",
"\176\175\337\175\043\300\041",
"\176\175\137\175\043\100\041",
NULL,
};
static u_char *
HdlcDetect(u_char * cp, int n)
{
char *ptr, *fp, **hp;
cp[n] = '\0'; /* be sure to null terminated */
ptr = NULL;
for (hp = FrameHeaders; *hp; hp++) {
fp = *hp;
if (DEV_IS_SYNC)
fp++;
ptr = strstr((char *) cp, fp);
if (ptr)
break;
}
return ((u_char *) ptr);
}
static struct pppTimer RedialTimer;
static void
RedialTimeout()
{
StopTimer(&RedialTimer);
LogPrintf(LogPHASE, "Redialing timer expired.\n");
}
static void
StartRedialTimer(int Timeout)
{
StopTimer(&RedialTimer);
if (Timeout) {
RedialTimer.state = TIMER_STOPPED;
if (Timeout > 0)
RedialTimer.load = Timeout * SECTICKS;
else
RedialTimer.load = (random() % REDIAL_PERIOD) * SECTICKS;
LogPrintf(LogPHASE, "Enter pause (%d) for redialing.\n",
RedialTimer.load / SECTICKS);
RedialTimer.func = RedialTimeout;
StartTimer(&RedialTimer);
}
}
static void
DoLoop()
{
fd_set rfds, wfds, efds;
int pri, i, n, wfd, nfds;
struct sockaddr_in hisaddr;
struct timeval timeout, *tp;
int ssize = sizeof(hisaddr);
u_char *cp;
u_char rbuff[MAX_MRU];
int tries;
int qlen;
int res;
pid_t pgroup;
pgroup = getpgrp();
if (mode & MODE_DIRECT) {
LogPrintf(LogDEBUG, "Opening modem\n");
if (OpenModem() < 0)
return;
LogPrintf(LogPHASE, "Packet mode enabled\n");
PacketMode();
} else if (mode & MODE_DEDICATED) {
if (modem < 0)
while (OpenModem() < 0)
nointr_sleep(VarReconnectTimer);
}
fflush(VarTerm);
timeout.tv_sec = 0;
timeout.tv_usec = 0;
reconnectState = RECON_UNKNOWN;
if (mode & MODE_BACKGROUND)
dial_up = 1; /* Bring the line up */
else
dial_up = 0; /* XXXX */
tries = 0;
for (;;) {
nfds = 0;
FD_ZERO(&rfds);
FD_ZERO(&wfds);
FD_ZERO(&efds);
/*
* If the link is down and we're in DDIAL mode, bring it back up.
*/
if (mode & MODE_DDIAL && LcpFsm.state <= ST_CLOSED)
dial_up = 1;
/*
* If we lost carrier and want to re-establish the connection due to the
* "set reconnect" value, we'd better bring the line back up.
*/
if (LcpFsm.state <= ST_CLOSED) {
if (!dial_up && reconnectState == RECON_TRUE) {
if (++reconnectCount <= VarReconnectTries) {
LogPrintf(LogPHASE, "Connection lost, re-establish (%d/%d)\n",
reconnectCount, VarReconnectTries);
StartRedialTimer(VarReconnectTimer);
dial_up = 1;
} else {
if (VarReconnectTries)
LogPrintf(LogPHASE, "Connection lost, maximum (%d) times\n",
VarReconnectTries);
reconnectCount = 0;
if (mode & MODE_BACKGROUND)
Cleanup(EX_DEAD);
}
reconnectState = RECON_ENVOKED;
} else if (mode & MODE_DEDICATED)
if (VarOpenMode == OPEN_ACTIVE)
PacketMode();
}
/*
* If Ip packet for output is enqueued and require dial up, Just do it!
*/
if (dial_up && RedialTimer.state != TIMER_RUNNING) {
LogPrintf(LogDEBUG, "going to dial: modem = %d\n", modem);
if (OpenModem() < 0) {
tries++;
if (!(mode & MODE_DDIAL) && VarDialTries)
LogPrintf(LogCHAT, "Failed to open modem (attempt %u of %d)\n",
tries, VarDialTries);
else
LogPrintf(LogCHAT, "Failed to open modem (attempt %u)\n", tries);
if (!(mode & MODE_DDIAL) && VarDialTries && tries >= VarDialTries) {
if (mode & MODE_BACKGROUND)
Cleanup(EX_DIAL); /* Can't get the modem */
dial_up = 0;
reconnectState = RECON_UNKNOWN;
reconnectCount = 0;
tries = 0;
} else
StartRedialTimer(VarRedialTimeout);
} else {
tries++; /* Tries are per number, not per list of
* numbers. */
if (!(mode & MODE_DDIAL) && VarDialTries)
LogPrintf(LogCHAT, "Dial attempt %u of %d\n", tries, VarDialTries);
else
LogPrintf(LogCHAT, "Dial attempt %u\n", tries);
if ((res = DialModem()) == EX_DONE) {
nointr_sleep(1); /* little pause to allow peer starts */
ModemTimeout();
PacketMode();
dial_up = 0;
reconnectState = RECON_UNKNOWN;
tries = 0;
} else {
if (mode & MODE_BACKGROUND) {
if (VarNextPhone == NULL || res == EX_SIG)
Cleanup(EX_DIAL); /* Tried all numbers - no luck */
else
/* Try all numbers in background mode */
StartRedialTimer(VarRedialNextTimeout);
} else if (!(mode & MODE_DDIAL) &&
((VarDialTries && tries >= VarDialTries) ||
res == EX_SIG)) {
/* I give up ! Can't get through :( */
StartRedialTimer(VarRedialTimeout);
dial_up = 0;
reconnectState = RECON_UNKNOWN;
reconnectCount = 0;
tries = 0;
} else if (VarNextPhone == NULL)
/* Dial failed. Keep quite during redial wait period. */
StartRedialTimer(VarRedialTimeout);
else
StartRedialTimer(VarRedialNextTimeout);
}
}
}
qlen = ModemQlen();
if (qlen == 0) {
IpStartOutput();
qlen = ModemQlen();
}
if (modem >= 0) {
if (modem + 1 > nfds)
nfds = modem + 1;
FD_SET(modem, &rfds);
FD_SET(modem, &efds);
if (qlen > 0) {
FD_SET(modem, &wfds);
}
}
if (server >= 0) {
if (server + 1 > nfds)
nfds = server + 1;
FD_SET(server, &rfds);
}
/*
* *** IMPORTANT ***
*
* CPU is serviced every TICKUNIT micro seconds. This value must be chosen
* with great care. If this values is too big, it results loss of
* characters from modem and poor responce. If this values is too small,
* ppp process eats many CPU time.
*/
#ifndef SIGALRM
nointr_usleep(TICKUNIT);
TimerService();
#else
handle_signals();
#endif
/* If there are aren't many packets queued, look for some more. */
if (qlen < 20 && tun_in >= 0) {
if (tun_in + 1 > nfds)
nfds = tun_in + 1;
FD_SET(tun_in, &rfds);
}
if (netfd >= 0) {
if (netfd + 1 > nfds)
nfds = netfd + 1;
FD_SET(netfd, &rfds);
FD_SET(netfd, &efds);
}
#ifndef SIGALRM
/*
* Normally, select() will not block because modem is writable. In AUTO
* mode, select will block until we find packet from tun
*/
tp = (RedialTimer.state == TIMER_RUNNING) ? &timeout : NULL;
i = select(nfds, &rfds, &wfds, &efds, tp);
#else
/*
* When SIGALRM timer is running, a select function will be return -1 and
* EINTR after a Time Service signal hundler is done. If the redial
* timer is not running and we are trying to dial, poll with a 0 value
* timer.
*/
tp = (dial_up && RedialTimer.state != TIMER_RUNNING) ? &timeout : NULL;
i = select(nfds, &rfds, &wfds, &efds, tp);
#endif
if (i == 0) {
continue;
}
if (i < 0) {
if (errno == EINTR) {
handle_signals();
continue;
}
LogPrintf(LogERROR, "DoLoop: select(): %s\n", strerror(errno));
break;
}
if ((netfd >= 0 && FD_ISSET(netfd, &efds)) || (modem >= 0 && FD_ISSET(modem, &efds))) {
LogPrintf(LogALERT, "Exception detected.\n");
break;
}
if (server >= 0 && FD_ISSET(server, &rfds)) {
LogPrintf(LogPHASE, "connected to client.\n");
wfd = accept(server, (struct sockaddr *) & hisaddr, &ssize);
if (wfd < 0) {
LogPrintf(LogERROR, "DoLoop: accept(): %s\n", strerror(errno));
continue;
}
if (netfd >= 0) {
write(wfd, "already in use.\n", 16);
close(wfd);
continue;
} else
netfd = wfd;
VarTerm = fdopen(netfd, "a+");
LocalAuthInit();
Greetings();
IsInteractive(1);
Prompt();
}
if (netfd >= 0 && FD_ISSET(netfd, &rfds) &&
((mode & MODE_OUTGOING_DAEMON) || pgroup == tcgetpgrp(0))) {
/* something to read from tty */
ReadTty();
}
if (modem >= 0) {
if (FD_ISSET(modem, &wfds)) { /* ready to write into modem */
ModemStartOutput(modem);
}
if (FD_ISSET(modem, &rfds)) { /* something to read from modem */
if (LcpFsm.state <= ST_CLOSED)
nointr_usleep(10000);
n = read(modem, rbuff, sizeof(rbuff));
if ((mode & MODE_DIRECT) && n <= 0) {
DownConnection();
} else
LogDumpBuff(LogASYNC, "ReadFromModem", rbuff, n);
if (LcpFsm.state <= ST_CLOSED) {
/*
* In dedicated mode, we just discard input until LCP is started.
*/
if (!(mode & MODE_DEDICATED)) {
cp = HdlcDetect(rbuff, n);
if (cp) {
/*
* LCP packet is detected. Turn ourselves into packet mode.
*/
if (cp != rbuff) {
write(modem, rbuff, cp - rbuff);
write(modem, "\r\n", 2);
}
PacketMode();
} else
write(fileno(VarTerm), rbuff, n);
}
} else {
if (n > 0)
AsyncInput(rbuff, n);
}
}
}
if (tun_in >= 0 && FD_ISSET(tun_in, &rfds)) { /* something to read
* from tun */
n = read(tun_in, rbuff, sizeof(rbuff));
if (n < 0) {
LogPrintf(LogERROR, "read from tun: %s\n", strerror(errno));
continue;
}
if (((struct ip *) rbuff)->ip_dst.s_addr == IpcpInfo.want_ipaddr.s_addr) {
/* we've been asked to send something addressed *to* us :( */
if (VarLoopback) {
pri = PacketCheck(rbuff, n, FL_IN);
if (pri >= 0) {
struct mbuf *bp;
if (mode & MODE_ALIAS) {
VarPacketAliasIn(rbuff, sizeof rbuff);
n = ntohs(((struct ip *) rbuff)->ip_len);
}
bp = mballoc(n, MB_IPIN);
memcpy(MBUF_CTOP(bp), rbuff, n);
IpInput(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 (LcpFsm.state <= ST_CLOSED && (mode & MODE_AUTO)) {
pri = PacketCheck(rbuff, n, FL_DIAL);
if (pri >= 0) {
if (mode & MODE_ALIAS) {
VarPacketAliasOut(rbuff, sizeof rbuff);
n = ntohs(((struct ip *) rbuff)->ip_len);
}
IpEnqueue(pri, rbuff, n);
dial_up = 1; /* XXX */
}
continue;
}
pri = PacketCheck(rbuff, n, FL_OUT);
if (pri >= 0) {
if (mode & MODE_ALIAS) {
VarPacketAliasOut(rbuff, sizeof rbuff);
n = ntohs(((struct ip *) rbuff)->ip_len);
}
IpEnqueue(pri, rbuff, n);
}
}
}
LogPrintf(LogDEBUG, "Job (DoLoop) done.\n");
}
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