/* * 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #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); }