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freshtomato-arm/release/src-rt-6.x.4708/router/p910nd/p910nd.c

736 lines
21 KiB
C

/*
* Port 9100+n daemon
* Accepts a connection from port 9100+n and copy stream to
* /dev/lpn, where n = 0,1,2.
*
* GPLv2 license, read COPYING
*
* Run standalone as: p910nd [0|1|2]
*
* Run under inetd as:
* p910n stream tcp nowait root /usr/sbin/tcpd p910nd [0|1|2]
* where p910n is an /etc/services entry for
* port 9100, 9101 or 9102 as the case may be.
* root can be replaced by any uid with rw permission on /dev/lpn
*
* Port 9100+n will then be passively opened
* n defaults to 0
*
* Version 0.97
* Patches by Stefan Sichler.
* Stream to printer is only closed after EOF from network if
* it is no more busy, otherwise printer driver may discard data of last
* write() at close().
*
* Version 0.96
* Patches by Stefan Sichler.
* Fixed bi-directional mode to stay alive until connection is closed.
* Fixed timeout value in select() (controlling in/out balancing).
* Fixed network-to-printer buffer reporting EOF although there was data
* left in the buffer.
* Added log-to-stdout option (-d).
*
* Version 0.95
* Patch by Mario Izquierdo
* Fix incomplete conversion to manipulate new ip_addr structure
* when LIBWRAP is selected
*
* Version 0.94
* Patch by Guenther Niess:
* Support IPv6
* Patch by Philip Prindeville:
* Increase socket buffer size
* Use %hu for printing port
* Makefile fixes for LIBWRAP
*
* Version 0.93
* Fix open call to include mode, required for O_CREAT
*
* Version 0.92
* Patches by Dave Brown. Use raw I/O syscalls instead of
* stdio buffering. Buffer system to handle talkative bidi
* devices better on low-powered hosts.
*
* Version 0.91
* Patch by Hans Harder. Close printer device after each use to
* avoid crashing when hotpluggable devices going away.
* Don't wait 10 seconds after successful open.
*
* Version 0.9
* Patch by Kostas Liakakis to keep retrying every 10 seconds
* if EBUSY is returned by open_printer, apparently NetBSD
* does this if the printer is not on.
* Patch by Albert Bartoszko (al_bin@vp_pl), August 2006
* Work with hotpluggable devices
* Improve Makefile
*
* (The last two patches conflict somewhat, Liakakis's patch
* retries opening the device every 10 seconds until successful,
* whereas Bartoszko's patch exits if the printer device cannot be opened.
* The problem is with a hotpluggable device, that device node may
* not appear again.
*
* I have opted for Liakakis's behaviour. Let me know if this can
* be improved. Perhaps we need another option that chooses the
* behaviour. - Ken)
*
* Version 0.8
* Allow specifying address to bind to
*
* Version 0.7
* Bidirectional data transfer
*
* Version 0.6
* Arne Bernin fixed some cast warnings, corrected the version number
* and added a -v option to print the version.
*
* Version 0.5
* -DUSE_LIBWRAP and -lwrap enables hosts_access (tcpwrappers) checking.
*
* Version 0.4
* Ken Yap (greenpossum@users.sourceforge.net), April 2001
* Placed under GPL.
*
* Added -f switch to specify device which overrides /dev/lpn.
* But number is still required get distinct ports and locks.
*
* Added locking so that two invocations of the daemon under inetd
* don't try to open the printer at the same time. This can happen
* even if there is one host running clients because the previous
* client can exit after it has sent all data but the printer has not
* finished printing and inetd starts up a new daemon when the next
* request comes in too soon.
*
* Various things could be Linux specific. I don't
* think there is much demand for this program outside of PCs,
* but if you port it to other distributions or platforms,
* I'd be happy to receive your patches.
*/
#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <getopt.h>
#include <ctype.h>
#include <string.h>
#include <fcntl.h>
#include <netdb.h>
#include <syslog.h>
#include <errno.h>
#include <stdarg.h>
#include <sys/types.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <sys/stat.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#ifdef USE_LIBWRAP
#include "tcpd.h"
int allow_severity, deny_severity;
extern int hosts_ctl(char *daemon, char *client_name, char *client_addr, char *client_user);
#endif
#define BASEPORT 9100
#define PIDFILE "/var/run/p910%cd.pid"
#ifdef LOCKFILE_DIR
#define LOCKFILE LOCKFILE_DIR "/p910%cd"
#else
#define LOCKFILE "/var/lock/subsys/p910%cd"
#endif
#ifndef PRINTERFILE
#define PRINTERFILE "/dev/lp%c"
#endif
#define LOGOPTS LOG_ERR
#define BUFFER_SIZE 8192
/* Circular buffer used for each direction. */
typedef struct {
int detectEof; /* If nonzero, EOF is marked when read returns 0 bytes. */
int infd; /* Input file descriptor. */
int outfd; /* Output file descriptor. */
int startidx; /* Index of the start of valid data. */
int endidx; /* Index of the end of valid data. */
int bytes; /* The number of bytes currently buffered. */
int totalin; /* Total bytes that have been read. */
int totalout; /* Total bytes that have been written. */
int eof_read; /* Nonzero indicates the input file has reached EOF. */
int eof_sent; /* Nonzero indicates the output file has fully received all data. */
int err; /* Nonzero indicates an error detected on the output file. */
char buffer[BUFFER_SIZE]; /* Buffered data goes here. */
} Buffer_t;
static char *progname;
static char version[] = "Version 0.97";
static char copyright[] = "Copyright (c) 2008-2014 Ken Yap and others, GPLv2";
static int lockfd = -1;
static char *device = 0;
static int bidir = 0;
static char *bindaddr = 0;
static int log_to_stdout = 0;
/* Helper function: convert a struct sockaddr address (IPv4 and IPv6) to a string */
char *get_ip_str(const struct sockaddr *sa, char *s, size_t maxlen)
{
switch(sa->sa_family) {
case AF_INET:
inet_ntop(AF_INET, &(((struct sockaddr_in *)sa)->sin_addr), s, maxlen);
break;
case AF_INET6:
inet_ntop(AF_INET6, &(((struct sockaddr_in6 *)sa)->sin6_addr), s, maxlen);
break;
default:
strncpy(s, "Unknown AF", maxlen);
return NULL;
}
return s;
}
uint16_t get_port(const struct sockaddr *sa)
{
uint16_t port;
switch(sa->sa_family) {
case AF_INET:
port = ntohs(((struct sockaddr_in *)sa)->sin_port);
break;
case AF_INET6:
port = ntohs(((struct sockaddr_in6 *)sa)->sin6_port);
break;
default:
return 0;
}
return port;
}
void usage(void)
{
fprintf(stderr, "%s %s %s\n", progname, version, copyright);
fprintf(stderr, "Usage: %s [-f device] [-i bindaddr] [-bvd] [0|1|2]\n", progname);
exit(1);
}
void show_version(void)
{
fprintf(stdout, "%s %s\n", progname, version);
}
void dolog(int level, char* msg, ...)
{
va_list argp;
va_start(argp, msg);
if (log_to_stdout)
vfprintf(stdout, msg, argp);
else if (level != LOG_DEBUG)
vsyslog(level, msg, argp);
va_end(argp);
}
int open_printer(int lpnumber)
{
int lp;
char lpname[sizeof(PRINTERFILE)];
#ifdef TESTING
(void)snprintf(lpname, sizeof(lpname), "/dev/tty");
#else
(void)snprintf(lpname, sizeof(lpname), PRINTERFILE, lpnumber);
#endif
if (device == 0)
device = lpname;
if ((lp = open(device, bidir ? (O_RDWR|O_NONBLOCK) : O_WRONLY)) == -1) {
if (errno != EBUSY)
dolog(LOGOPTS, "%s: %m\n", device);
dolog(LOGOPTS, "%s: %m, will try opening later\n", device);
}
return (lp);
}
int get_lock(int lpnumber)
{
char lockname[sizeof(LOCKFILE)];
struct flock lplock;
(void)snprintf(lockname, sizeof(lockname), LOCKFILE, lpnumber);
if ((lockfd = open(lockname, O_CREAT | O_RDWR, 0666)) < 0) {
dolog(LOGOPTS, "%s: %m\n", lockname);
return (0);
}
memset(&lplock, 0, sizeof(lplock));
lplock.l_type = F_WRLCK;
lplock.l_pid = getpid();
if (fcntl(lockfd, F_SETLKW, &lplock) < 0) {
dolog(LOGOPTS, "%s: %m\n", lockname);
return (0);
}
return (1);
}
void free_lock(void)
{
if (lockfd >= 0)
(void)close(lockfd);
}
/* Initializes the buffer, at the start. */
void initBuffer(Buffer_t * b, int infd, int outfd, int detectEof)
{
b->detectEof = detectEof;
b->infd = infd;
b->outfd = outfd;
b->startidx = 0;
b->endidx = 0;
b->bytes = 0;
b->totalin = 0;
b->totalout = 0;
b->eof_read = 0;
b->eof_sent = 0;
b->err = 0;
}
/* Sets the readfds and writefds (used by select) based on current buffer state. */
void prepBuffer(Buffer_t * b, fd_set * readfds, fd_set * writefds)
{
if (b->outfd>=0 && !b->err && (b->bytes != 0 || b->eof_read)) {
FD_SET(b->outfd, writefds);
}
if (b->infd>=0 && !b->eof_read && b->bytes < sizeof(b->buffer)) {
FD_SET(b->infd, readfds);
}
}
/* Reads data into a buffer from its input file. */
ssize_t readBuffer(Buffer_t * b)
{
int avail;
ssize_t result = 0;
/* If err, the data will not be written, so no need to store it. */
if (b->bytes == 0 || b->err) {
/* The buffer is empty. */
b->startidx = b->endidx = 0;
avail = sizeof(b->buffer);
} else if (b->bytes == sizeof(b->buffer)) {
/* The buffer is full. */
avail = 0;
} else if (b->endidx > b->startidx) {
/* The buffer is not wrapped: from endidx to end of buffer is free. */
avail = sizeof(b->buffer) - b->endidx;
} else {
/* The buffer is wrapped: gap between endidx and startidx is free. */
avail = b->startidx - b->endidx;
}
if (avail) {
result = read(b->infd, b->buffer + b->endidx, avail);
if (result > 0) {
/* Some data was read. Update accordingly. */
b->endidx += result;
b->totalin += result;
b->bytes += result;
if (b->endidx == sizeof(b->buffer)) {
/* Time to wrap the buffer. */
b->endidx = 0;
}
} else if (result < 0) {
dolog(LOGOPTS, "read: %m\n");
b->err = 1;
}
else if (b->detectEof) {
dolog(LOG_DEBUG, "read: eof\n");
b->eof_read = 1;
} else
result = 0; // in case there is still data in the buffer, ignore the error by now
}
/* Return the value returned by read(), which is -1 (error), or #bytes read. */
return result;
}
/* Writes data from a buffer to the output file or discard if no output file is set. */
ssize_t writeBuffer(Buffer_t * b)
{
int avail;
ssize_t result = 0;
if (b->bytes == 0 || b->err) {
/* Buffer is empty. */
avail = 0;
} else if (b->endidx > b->startidx) {
/* Buffer is not wrapped. Can write all the data. */
avail = b->endidx - b->startidx;
} else {
/* Buffer is wrapped. Can only write the top (first) part. */
avail = sizeof(b->buffer) - b->startidx;
}
if (avail) {
if (b->outfd>=0)
result = write(b->outfd, b->buffer + b->startidx, avail);
else
result = avail;
if (result < 0) {
/* Mark the output file in an error condition. */
dolog(LOGOPTS, "write: %m\n");
b->err = 1;
} else {
/* Zero or more bytes were written. */
b->startidx += result;
if (b->outfd>=0)
b->totalout += result;
b->bytes -= result;
if (b->startidx == sizeof(b->buffer)) {
/* Unwrap the buffer. */
b->startidx = 0;
}
}
}
else if (b->eof_read)
b->eof_sent = 1;
/* Return the write() result, -1 (error) or #bytes written. */
return result;
}
/* Copy network data from file descriptor fd (network) to lp (printer) until EOS */
/* If bidir, also copy data from printer (lp) to network (fd). */
int copy_stream(int fd, int lp)
{
int result;
Buffer_t networkToPrinterBuffer;
initBuffer(&networkToPrinterBuffer, fd, lp, 1);
if (bidir) {
struct timeval now;
struct timeval then;
struct timeval timeout;
int timer = 0;
Buffer_t printerToNetworkBuffer;
initBuffer(&printerToNetworkBuffer, lp, fd, 0);
fd_set readfds;
fd_set writefds;
/* Finish when network sent EOF. */
/* Although the printer to network stream may not be finished (does this matter?) */
while (!networkToPrinterBuffer.eof_sent && !networkToPrinterBuffer.err) {
FD_ZERO(&readfds);
FD_ZERO(&writefds);
prepBuffer(&networkToPrinterBuffer, &readfds, &writefds);
prepBuffer(&printerToNetworkBuffer, &readfds, &writefds);
int maxfd = lp > fd ? lp : fd;
if (timer) {
/* Delay after reading from the printer, so the */
/* return stream cannot dominate. */
/* Don't read from the printer until the timer expires. */
gettimeofday(&now, 0);
if ((now.tv_sec > then.tv_sec) || (now.tv_sec == then.tv_sec && now.tv_usec > then.tv_usec))
timer = 0;
else
FD_CLR(lp, &readfds);
}
timeout.tv_sec = 0;
timeout.tv_usec = 100000;
result = select(maxfd + 1, &readfds, &writefds, 0, &timeout);
if (result < 0)
return (result);
if (FD_ISSET(fd, &readfds)) {
/* Read network data. */
result = readBuffer(&networkToPrinterBuffer);
if (result > 0)
dolog(LOG_DEBUG,"read %d bytes from network\n",result);
}
if (FD_ISSET(lp, &readfds)) {
/* Read printer data, but pace it more slowly. */
result = readBuffer(&printerToNetworkBuffer);
if (result > 0) {
dolog(LOG_DEBUG,"read %d bytes from printer\n",result);
gettimeofday(&then, 0);
// wait 100 msec before reading again.
then.tv_usec += 100000;
if (then.tv_usec > 1000000) {
then.tv_usec -= 1000000;
then.tv_sec++;
}
timer = 1;
}
}
if (FD_ISSET(lp, &writefds)) {
/* Write data to printer. */
result = writeBuffer(&networkToPrinterBuffer);
if (result > 0)
dolog(LOG_DEBUG,"wrote %d bytes to printer\n",result);
}
if (FD_ISSET(fd, &writefds) || printerToNetworkBuffer.outfd == -1) {
/* Write data to network. */
result = writeBuffer(&printerToNetworkBuffer);
/* If socket write error, discard further data from printer */
if (result < 0) {
printerToNetworkBuffer.outfd = -1;
printerToNetworkBuffer.err = 0;
result = 0;
dolog(LOG_DEBUG,"network write error, discarding further printer data\n",result);
}
else if (result > 0) {
if (printerToNetworkBuffer.outfd == -1)
dolog(LOG_DEBUG,"discarded %d bytes from printer\n",result);
else
dolog(LOG_DEBUG,"wrote %d bytes to network\n",result);
}
}
}
dolog(LOG_NOTICE,
"Finished job: %d/%d bytes sent to printer, %d/%d bytes sent to network\n",
networkToPrinterBuffer.totalout,networkToPrinterBuffer.totalin, printerToNetworkBuffer.totalout, printerToNetworkBuffer.totalin);
} else {
/* Unidirectional: simply read from network, and write to printer. */
while (!networkToPrinterBuffer.eof_sent && !networkToPrinterBuffer.err) {
result = readBuffer(&networkToPrinterBuffer);
if (result > 0)
dolog(LOG_DEBUG,"read %d bytes from network\n",result);
result = writeBuffer(&networkToPrinterBuffer);
if (result > 0)
dolog(LOG_DEBUG,"wrote %d bytes to printer\n",result);
}
dolog(LOG_NOTICE, "Finished job: %d/%d bytes sent to printer\n", networkToPrinterBuffer.totalout, networkToPrinterBuffer.totalin);
}
return (networkToPrinterBuffer.err?-1:0);
}
void one_job(int lpnumber)
{
int lp;
struct sockaddr_storage client;
socklen_t clientlen = sizeof(client);
if (getpeername(0, (struct sockaddr *)&client, &clientlen) >= 0) {
char host[INET6_ADDRSTRLEN];
dolog(LOG_NOTICE, "Connection from %s port %hu\n", get_ip_str((struct sockaddr *)&client, host, sizeof(host)), get_port((struct sockaddr *)&client));
}
if (get_lock(lpnumber) == 0)
return;
/* Make sure lp device is open... */
while ((lp = open_printer(lpnumber)) == -1)
sleep(10);
if (copy_stream(0, lp) < 0)
dolog(LOGOPTS, "copy_stream: %m\n");
close(lp);
free_lock();
}
void server(int lpnumber)
{
struct rlimit resourcelimit;
#ifdef USE_GETPROTOBYNAME
struct protoent *proto;
#endif
int netfd = -1, fd, lp, one = 1;
socklen_t clientlen;
struct sockaddr_storage client;
struct addrinfo hints, *res, *ressave;
char pidfilename[sizeof(PIDFILE)];
char service[sizeof(BASEPORT+lpnumber-'0')+1];
FILE *f;
const int bufsiz = 65536;
#ifndef TESTING
if (!log_to_stdout)
{
switch (fork()) {
case -1:
dolog(LOGOPTS, "fork: %m\n");
exit(1);
case 0: /* child */
break;
default: /* parent */
exit(0);
}
/* Now in child process */
resourcelimit.rlim_max = 0;
if (getrlimit(RLIMIT_NOFILE, &resourcelimit) < 0) {
dolog(LOGOPTS, "getrlimit: %m\n");
exit(1);
}
for (fd = 0; fd < resourcelimit.rlim_max; ++fd)
(void)close(fd);
if (setsid() < 0) {
dolog(LOGOPTS, "setsid: %m\n");
exit(1);
}
(void)chdir("/");
(void)umask(022);
fd = open("/dev/null", O_RDWR); /* stdin */
(void)dup(fd); /* stdout */
(void)dup(fd); /* stderr */
(void)snprintf(pidfilename, sizeof(pidfilename), PIDFILE, lpnumber);
if ((f = fopen(pidfilename, "w")) == NULL) {
dolog(LOGOPTS, "%s: %m\n", pidfilename);
exit(1);
}
(void)fprintf(f, "%d\n", getpid());
(void)fclose(f);
}
if (get_lock(lpnumber) == 0)
exit(1);
#endif
memset(&hints, 0, sizeof(hints));
hints.ai_family = PF_UNSPEC;
hints.ai_flags = AI_PASSIVE;
hints.ai_socktype = SOCK_STREAM;
(void)snprintf(service, sizeof(service), "%hu", (BASEPORT + lpnumber - '0'));
if (getaddrinfo(bindaddr, service, &hints, &res) != 0) {
dolog(LOGOPTS, "getaddr: %m\n");
exit(1);
}
ressave = res;
while (res) {
#ifdef USE_GETPROTOBYNAME
if ((proto = getprotobyname("tcp6")) == NULL) {
if ((proto = getprotobyname("tcp")) == NULL) {
dolog(LOGOPTS, "Cannot find protocol for TCP!\n");
exit(1);
}
}
if ((netfd = socket(res->ai_family, res->ai_socktype, proto->p_proto)) < 0)
#else
if ((netfd = socket(res->ai_family, res->ai_socktype, IPPROTO_IP)) < 0)
#endif
{
dolog(LOGOPTS, "socket: %m\n");
close(netfd);
res = res->ai_next;
continue;
}
if (setsockopt(netfd, SOL_SOCKET, SO_RCVBUF, &bufsiz, sizeof(bufsiz)) < 0) {
dolog(LOGOPTS, "setsocketopt: SO_RCVBUF: %m\n");
/* not fatal if it fails */
}
if (setsockopt(netfd, SOL_SOCKET, SO_SNDBUF, &bufsiz, sizeof(bufsiz)) < 0) {
dolog(LOGOPTS, "setsocketopt: SO_SNDBUF: %m\n");
/* not fatal if it fails */
}
if (setsockopt(netfd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one)) < 0) {
dolog(LOGOPTS, "setsocketopt: SO_REUSEADDR: %m\n");
close(netfd);
res = res->ai_next;
continue;
}
if (bind(netfd, res->ai_addr, res->ai_addrlen) < 0) {
dolog(LOGOPTS, "bind: %m\n");
close(netfd);
res = res->ai_next;
continue;
}
if (listen(netfd, 5) < 0) {
dolog(LOGOPTS, "listen: %m\n");
close(netfd);
res = res->ai_next;
continue;
}
break;
}
freeaddrinfo(ressave);
clientlen = sizeof(client);
memset(&client, 0, sizeof(client));
while ((fd = accept(netfd, (struct sockaddr *)&client, &clientlen)) >= 0) {
char host[INET6_ADDRSTRLEN];
#ifdef USE_LIBWRAP
if (hosts_ctl("p910nd", STRING_UNKNOWN, get_ip_str((struct sockaddr *)&client, host, sizeof(host)), STRING_UNKNOWN) == 0) {
dolog(LOGOPTS,
"Connection from %s port %hu rejected\n", get_ip_str((struct sockaddr *)&client, host, sizeof(host)), get_port((struct sockaddr *)&client));
close(fd);
continue;
}
#endif
dolog(LOG_NOTICE, "Connection from %s port %hu accepted\n", get_ip_str((struct sockaddr *)&client, host, sizeof(host)), get_port((struct sockaddr *)&client));
/*write(fd, "Printing", 8); */
/* Make sure lp device is open... */
while ((lp = open_printer(lpnumber)) == -1)
sleep(10);
if (copy_stream(fd, lp) < 0)
dolog(LOGOPTS, "copy_stream: %m\n");
(void)close(fd);
(void)close(lp);
}
dolog(LOGOPTS, "accept: %m\n");
free_lock();
exit(1);
}
int is_standalone(void)
{
struct sockaddr_storage bind_addr;
socklen_t ba_len;
/*
* Check to see if a socket was passed to us from (x)inetd.
*
* Use getsockname() to determine if descriptor 0 is indeed a socket
* (and thus we are probably a child of (x)inetd) or if it is instead
* something else and we are running standalone.
*/
ba_len = sizeof(bind_addr);
if (getsockname(0, (struct sockaddr *)&bind_addr, &ba_len) == 0)
return (0); /* under (x)inetd */
if (errno != ENOTSOCK) /* strange... */
dolog(LOGOPTS, "getsockname: %m\n");
return (1);
}
int main(int argc, char *argv[])
{
int c, lpnumber;
char *p;
if (argc <= 0) /* in case not provided in (x)inetd config */
progname = "p910nd";
else {
progname = argv[0];
if ((p = strrchr(progname, '/')) != 0)
progname = p + 1;
}
lpnumber = '0';
while ((c = getopt(argc, argv, "bdi:f:v")) != EOF) {
switch (c) {
case 'b':
bidir = 1;
break;
case 'd':
log_to_stdout = 1;
break;
case 'f':
device = optarg;
break;
case 'i':
bindaddr = optarg;
break;
case 'v':
show_version();
break;
default:
usage();
break;
}
}
argc -= optind;
argv += optind;
if (argc > 0) {
if (isdigit(argv[0][0]))
lpnumber = argv[0][0];
}
/* change the n in argv[0] to match the port so ps will show that */
if ((p = strstr(progname, "p910n")) != NULL)
p[4] = lpnumber;
/* We used to pass (LOG_PERROR|LOG_PID|LOG_LPR|LOG_ERR) to syslog, but
* syslog ignored the LOG_PID and LOG_PERROR option. I.e. the intention
* was to add both options but the effect was to have neither.
* I disagree with the intention to add PERROR. --Stef */
if (!log_to_stdout)
openlog(p, LOG_PID, LOG_LPR);
if (log_to_stdout || is_standalone())
server(lpnumber);
else
one_job(lpnumber);
return (0);
}