/* * NtripServerLinux.c * * Copyright (c) 2003...2005 * German Federal Agency for Cartography and Geodesy (BKG) * * Developed for Networked Transport of RTCM via Internet Protocol (NTRIP) * for streaming GNSS data over the Internet. * * Designed by Informatik Centrum Dortmund http://www.icd.de * * NTRIP is currently an experimental technology. * The BKG disclaims any liability nor responsibility to any person or * entity with respect to any loss or damage caused, or alleged to be * caused, directly or indirectly by the use and application of the NTRIP * technology. * * For latest information and updates, access: * http://igs.ifag.de/index_ntrip.htm * * Georg Weber * BKG, Frankfurt, Germany, June 2003-06-13 * E-mail: euref-ip@bkg.bund.de * * Based on the GNU General Public License published nmead * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version 2 * of the License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, * USA. */ /* $Id: NtripLinuxServer.c,v 1.22 2006/08/03 15:36:57 stoecker Exp $ * Changes - Version 0.7 * Sep 22 2003 Steffen Tschirpke * - socket support * - command line option handling * - error handling * - help screen * * Changes - Version 0.9 * Feb 15 2005 Dirk Stoecker * - some minor updates, fixed serial baudrate settings * * Changes - Version 0.10 * Apr 05 2005 Dirk Stoecker * - some cleanup and miscellaneous fixes * - replaced non-working simulate with file input (stdin) * - TCP sending now somewhat more stable * - cleanup of error handling * - Modes may be symbolic and not only numeric * * Changes - Version 0.11 * Jun 02 2005 Dirk Stoecker * - added SISNeT support * - added UDP support * - cleanup of host and port handling * - added inactivity alarm of 60 seconds * * Changes - Version 0.12 * Jun 07 2005 Dirk Stoecker * - added UDP bindmode * * Changes - Version 0.13 * Apr 25 2006 Andrea Stuerze * - added stream retrieval from caster * * Changes - Version 0.14 * May 16 2006 Andrea Stuerze * - bug fix in base64_encode-function * * Changes - Version 0.15 * Jun 02 2006 Georg Weber * - modification for SISNeT 3.1 protocol * * Changes - Version 0.16 * Jul 06 2006 Andrea Stuerze * - more flexible caster's response * * Changes - Version 0.17 * Jul 27 2006 Dirk Stoecker * - fixed some problems with caster download * - some minor cosmetic changes * */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifndef MSG_DONTWAIT #define MSG_DONTWAIT 0 /* prevent compiler errors */ #endif #ifndef O_EXLOCK #define O_EXLOCK 0 /* prevent compiler errors */ #endif enum MODE { SERIAL = 1, TCPSOCKET = 2, INFILE = 3, SISNET = 4, UDPSOCKET = 5, CASTER = 6, LAST}; #define VERSION "NTRIP NtripServerLinux/0.17" #define BUFSZ 1024 /* default socket source */ #define SERV_HOST_ADDR "127.0.0.1" #define SERV_TCP_PORT 1025 /* default destination */ #define NTRIP_CASTER "www.euref-ip.net" #define NTRIP_PORT 80 /* default sisnet source */ #define SISNET_SERVER "131.176.49.142" #define SISNET_PORT 7777 #define ALARMTIME 60 static int ttybaud = 19200; static const char *ttyport = "/dev/gps"; static const char *filepath = "/dev/stdin"; static enum MODE mode = INFILE; static int sisnet = 31; static int gpsfd = -1; /* Forward references */ static int openserial(const char * tty, int blocksz, int baud); static void send_receive_loop(int sock, int fd); static void usage(int); static int encode(char *buf, int size, const char *user, const char *pwd); #ifdef __GNUC__ static __attribute__ ((noreturn)) void sighandler_alarm( int sig __attribute__((__unused__))) #else /* __GNUC__ */ static void sighandler_alarm(int sig) #endif /* __GNUC__ */ { fprintf(stderr, "ERROR: more than %d seconds no activity\n", ALARMTIME); exit(1); } /* * main * * Main entry point for the program. Processes command-line arguments and * prepares for action. * * Parameters: * argc : integer : Number of command-line arguments. * argv : array of char : Command-line arguments as an array of * zero-terminated pointers to strings. * * Return Value: * The function does not return a value (although its return type is int). * * Remarks: * */ int main(int argc, char **argv) { int c; int size = 2048; /* for setting send buffer size */ const char *inhost = 0; const char *outhost = 0; unsigned int outport = 0; unsigned int inport = 0; const char *mountpoint = NULL; const char *password = ""; const char *sisnetpassword = ""; const char *sisnetuser = ""; const char *stream_name=0; const char *stream_user=0; const char *stream_password=0; const char *initfile = NULL; int bindmode = 0; int sock_id; char szSendBuffer[BUFSZ]; int nBufferBytes; struct hostent *he; struct sockaddr_in addr; signal(SIGALRM,sighandler_alarm); alarm(ALARMTIME); /* get and check program arguments */ if(argc <= 1) { usage(2); exit(1); } while((c = getopt(argc, argv, "M:i:h:b:p:s:a:m:c:H:P:f:l:u:V:D:U:W:B")) != EOF) { switch (c) { case 'M': if(!strcmp(optarg, "serial")) mode = SERIAL; else if(!strcmp(optarg, "tcpsocket")) mode = TCPSOCKET; else if(!strcmp(optarg, "file")) mode = INFILE; else if(!strcmp(optarg, "sisnet")) mode = SISNET; else if(!strcmp(optarg, "udpsocket")) mode = UDPSOCKET; else if(!strcmp(optarg, "caster")) mode = CASTER; else mode = atoi(optarg); if((mode == 0) || (mode >= LAST)) { fprintf(stderr, "ERROR: can't convert %s to a valid mode\n", optarg); usage(-1); } break; case 'i': /* gps serial ttyport */ ttyport = optarg; break; case 'B': bindmode = 1; break; case 'V': if(!strcmp("3.0", optarg)) sisnet = 30; else if(!strcmp("3.1", optarg)) sisnet = 31; else if(!strcmp("2.1", optarg)) sisnet = 21; else { fprintf(stderr, "ERROR: unknown SISNeT version %s\n", optarg); usage(-2); } break; case 'b': /* serial ttyin speed */ ttybaud = atoi(optarg); if(ttybaud <= 1) { fprintf(stderr, "ERROR: can't convert %s to valid serial speed\n", optarg); usage(1); } break; case 'a': /* http server IP address A.B.C.D */ outhost = optarg; break; case 'p': /* http server port */ outport = atoi(optarg); if(outport <= 1 || outport > 65535) { fprintf(stderr, "ERROR: can't convert %s to a valid HTTP server port\n", optarg); usage(1); } break; case 'm': /* http server mountpoint */ mountpoint = optarg; break; case 's': /* datastream from file */ filepath = optarg; break; case 'f': initfile = optarg; break; case 'u': sisnetuser = optarg; break; case 'l': sisnetpassword = optarg; break; case 'c': /* password */ password = optarg; break; case 'H': /* host */ inhost = optarg; break; case 'P': /* port */ inport = atoi(optarg); if(inport <= 1 || inport > 65535) { fprintf(stderr, "ERROR: can't convert %s to a valid port number\n", optarg); usage(1); } break; case 'D': stream_name=optarg; /* desired stream from SourceCaster */ break; case 'U': stream_user=optarg; /* username for desired stream */ break; case 'W': stream_password=optarg; /* passwd for desired stream */ break; case 'h': /* help */ case '?': usage(0); break; default: usage(2); break; } } argc -= optind; argv += optind; if(argc > 0) { fprintf(stderr, "ERROR: Extra args on command line: "); for(; argc > 0; argc--) { fprintf(stderr, " %s", *argv++); } fprintf(stderr, "\n"); usage(1); /* never returns */ } if(mountpoint == NULL) { fprintf(stderr, "ERROR: Missing mountpoint argument\n"); exit(1); } if(!password[0]) { fprintf(stderr, "WARNING: Missing password argument - are you really sure?\n"); } if(stream_name && stream_user && !stream_password) { fprintf(stderr, "WARNING: Missing password argument for download" " - are you really sure?\n"); } if(!outhost) outhost = NTRIP_CASTER; if(!outport) outport = NTRIP_PORT; switch(mode) { case INFILE: { if((gpsfd = open(filepath, O_RDONLY)) < 0) { perror("ERROR: opening input file"); exit(1); } /* set blocking mode in case it was not set (seems to be sometimes for fifo's) */ fcntl(gpsfd, F_SETFL, 0); printf("file input: file = %s\n", filepath); } break; case SERIAL: /* open serial port */ { gpsfd = openserial(ttyport, 1, ttybaud); if(gpsfd < 0) { exit(1); } printf("serial input: device = %s, speed = %d\n", ttyport, ttybaud); } break; case TCPSOCKET: case UDPSOCKET: case SISNET: case CASTER: { if(mode == SISNET) { if(!inhost) inhost = SISNET_SERVER; if(!inport) inport = SISNET_PORT; } else if(mode == CASTER) { if(!inport) inport = NTRIP_PORT; if(!inhost) inhost = NTRIP_CASTER; } else if((mode == TCPSOCKET) || (mode == UDPSOCKET)) { if(!inport) inport = SERV_TCP_PORT; if(!inhost) inhost = "127.0.0.1"; } if(!(he = gethostbyname(inhost))) { fprintf(stderr, "ERROR: host %s unknown\n", inhost); usage(-2); } if((gpsfd = socket(AF_INET, mode == UDPSOCKET ? SOCK_DGRAM : SOCK_STREAM, 0)) < 0) { fprintf(stderr, "ERROR: can't create socket\n"); exit(1); } memset((char *) &addr, 0x00, sizeof(addr)); if(!bindmode) memcpy(&addr.sin_addr, he->h_addr, (size_t)he->h_length); addr.sin_family = AF_INET; addr.sin_port = htons(inport); printf("%s input: host = %s, port = %d, %s%s%s%s%s\n", mode == CASTER ? "caster" : mode == SISNET ? "sisnet" : mode == TCPSOCKET ? "tcp socket" : "udp socket", bindmode ? "127.0.0.1" : inet_ntoa(addr.sin_addr), inport, stream_name ? "stream = " : "", stream_name ? stream_name : "", initfile ? ", initfile = " : "", initfile ? initfile : "", bindmode ? "binding mode" : ""); if(bindmode) { if(bind(gpsfd, (struct sockaddr *) &addr, sizeof(addr)) < 0) { fprintf(stderr, "ERROR: can't bind input to port %d\n", inport); exit(1); } } else if(connect(gpsfd, (struct sockaddr *) &addr, sizeof(addr)) < 0) { fprintf(stderr, "ERROR: can't connect input to %s at port %d\n", inet_ntoa(addr.sin_addr), inport); exit(1); } if(stream_name) /* data stream from caster */ { int init = 0; /* set socket buffer size */ setsockopt(gpsfd, SOL_SOCKET, SO_SNDBUF, (const char *) &size, sizeof(const char *)); if(stream_user && stream_password) { /* leave some space for login */ nBufferBytes=snprintf(szSendBuffer, sizeof(szSendBuffer)-40, "GET /%s HTTP/1.0\r\n" "User-Agent: %s\r\n" "Authorization: Basic ", stream_name, VERSION); /* second check for old glibc */ if(nBufferBytes > (int)sizeof(szSendBuffer)-40 || nBufferBytes < 0) { fprintf(stderr, "Requested data too long\n"); exit(1); } nBufferBytes += encode(szSendBuffer+nBufferBytes, sizeof(szSendBuffer)-nBufferBytes-5, stream_user, stream_password); if(nBufferBytes > (int)sizeof(szSendBuffer)-5) { fprintf(stderr, "Username and/or password too long\n"); exit(1); } snprintf(szSendBuffer+nBufferBytes, 5, "\r\n\r\n"); nBufferBytes += 5; } else { nBufferBytes = snprintf(szSendBuffer, sizeof(szSendBuffer), "GET /%s HTTP/1.0\r\n" "User-Agent: %s\r\n" "\r\n", stream_name, VERSION); } if((send(gpsfd, szSendBuffer, (size_t)nBufferBytes, 0)) != nBufferBytes) { fprintf(stderr, "ERROR: could not send to caster\n"); exit(1); } nBufferBytes = 0; /* check caster's response */ while(!init && nBufferBytes < (int)sizeof(szSendBuffer) && (nBufferBytes += recv(gpsfd, szSendBuffer, sizeof(szSendBuffer)-nBufferBytes, 0)) > 0) { if(strstr(szSendBuffer, "\r\n")) { if(!strncmp(szSendBuffer, "ICY 200 OK\r\n", 10)) init = 1; else { int k; fprintf(stderr, "Could not get the requested data: "); for(k = 0; k < nBufferBytes && szSendBuffer[k] != '\n' && szSendBuffer[k] != '\r'; ++k) { fprintf(stderr, "%c", isprint(szSendBuffer[k]) ? szSendBuffer[k] : '.'); } fprintf(stderr, "\n"); exit(1); } } } if(!init) { fprintf(stderr, "Could not init caster download."); exit(1); } } /* end data stream from caster */ if(initfile && mode != SISNET) { char buffer[1024]; FILE *fh; int i; if((fh = fopen(initfile, "r"))) { while((i = fread(buffer, 1, sizeof(buffer), fh)) > 0) { if((send(gpsfd, buffer, (size_t)i, 0)) != i) { perror("ERROR: sending init file"); exit(1); } } if(i < 0) { perror("ERROR: reading init file"); exit(1); } fclose(fh); } else { fprintf(stderr, "ERROR: can't read init file %s\n", initfile); exit(1); } } } if(mode == SISNET) { int i, j; char buffer[1024]; i = snprintf(buffer, sizeof(buffer), sisnet >= 30 ? "AUTH,%s,%s\r\n" : "AUTH,%s,%s", sisnetuser, sisnetpassword); if((send(gpsfd, buffer, (size_t)i, 0)) != i) { perror("ERROR: sending authentication"); exit(1); } i = sisnet >= 30 ? 7 : 5; if((j = recv(gpsfd, buffer, i, 0)) != i && strncmp("*AUTH", buffer, 5)) { fprintf(stderr, "ERROR: SISNeT connect failed:"); for(i = 0; i < j; ++i) { if(buffer[i] != '\r' && buffer[i] != '\n') { fprintf(stderr, "%c", isprint(buffer[i]) ? buffer[i] : '.'); } } fprintf(stderr, "\n"); exit(1); } if(sisnet >= 31) { if((send(gpsfd, "START\r\n", 7, 0)) != i) { perror("ERROR: sending start command"); exit(1); } } } break; default: usage(-1); break; } /* ----- main part ----- */ for(;;) { if(!(he = gethostbyname(outhost))) { fprintf(stderr, "ERROR: host %s unknown\n", outhost); usage(-2); } /* create socket */ if((sock_id = socket(AF_INET, SOCK_STREAM, 0)) < 0) { fprintf(stderr, "ERROR: could not create socket\n"); exit(2); } memset((char *) &addr, 0x00, sizeof(addr)); memcpy(&addr.sin_addr, he->h_addr, (size_t)he->h_length); addr.sin_family = AF_INET; addr.sin_port = htons(outport); /* connect to caster */ fprintf(stderr, "caster output: host = %s, port = %d, mountpoint = %s\n", inet_ntoa(addr.sin_addr), outport, mountpoint); if(connect(sock_id, (struct sockaddr *) &addr, sizeof(addr)) < 0) { fprintf(stderr, "ERROR: can't connect output to %s at port %d\n", inet_ntoa(addr.sin_addr), outport); close(sock_id); exit(3); } /* set socket buffer size */ setsockopt(sock_id, SOL_SOCKET, SO_SNDBUF, (const char *) &size, sizeof(const char *)); /* send message to caster */ szSendBuffer[0] = '\0'; sprintf(szSendBuffer, "SOURCE %s /%s\r\n", password, mountpoint); strcat(szSendBuffer, "Source-Agent: "); strcat(szSendBuffer, VERSION); strcat(szSendBuffer, "\r\n"); strcat(szSendBuffer, "\r\n"); strcat(szSendBuffer, "\0"); nBufferBytes = strlen(szSendBuffer); if((send(sock_id, szSendBuffer, (size_t)nBufferBytes, 0)) != nBufferBytes) { fprintf(stderr, "ERROR: could not send to caster\n"); break; } /* check caster's response */ nBufferBytes = recv(sock_id, szSendBuffer, sizeof(szSendBuffer), 0); szSendBuffer[nBufferBytes] = '\0'; if(!strstr(szSendBuffer, "OK")) { char *a; fprintf(stderr, "ERROR: caster's reply is not OK : "); for(a = szSendBuffer; *a && *a != '\n' && *a != '\r'; ++a) { fprintf(stderr, "%.1s", isprint(*a) ? a : "."); } fprintf(stderr, "\n"); break; } printf("connection successfull\n"); send_receive_loop(sock_id, gpsfd); } close(sock_id); sleep(5); return 0; } static void send_receive_loop(int sock, int fd) { int nodata = 0; char buffer[BUFSZ] = { 0 }; char sisnetbackbuffer[200]; int nBufferBytes = 0; /* data transmission */ printf("transfering data ...\n"); while(1) { if(!nodata) alarm(ALARMTIME); else nodata = 0; if(!nBufferBytes) { if(mode == SISNET && sisnet <= 30) { int i; /* a somewhat higher rate than 1 second to get really each block */ /* means we need to skip double blocks sometimes */ struct timeval tv = {0,700000}; select(0, 0, 0, 0, &tv); memcpy(sisnetbackbuffer, buffer, sizeof(sisnetbackbuffer)); i = (sisnet >= 30 ? 5 : 3); if((send(gpsfd, "MSG\r\n", i, 0)) != i) { perror("ERROR: sending data request"); exit(1); } } /* receiving data */ nBufferBytes = read(fd, buffer, sizeof(buffer)); if(!nBufferBytes) { printf("WARNING: no data received from input\n"); sleep(3); nodata = 1; continue; } else if(nBufferBytes < 0) { perror("ERROR: reading input failed"); exit(1); } /* we can compare the whole buffer, as the additional bytes remain unchanged */ if(mode == SISNET && sisnet <= 30 && !memcmp(sisnetbackbuffer, buffer, sizeof(sisnetbackbuffer))) { nBufferBytes = 0; } } if(nBufferBytes) { int i; /* send data */ if((i = send(sock, buffer, (size_t)nBufferBytes, MSG_DONTWAIT)) != nBufferBytes) { if(i < 0) { if(errno != EAGAIN) { perror("WARNING: could not send data - retry connection"); close(sock); sleep(5); return; } } else if(i) { memmove(buffer, buffer+i, (size_t)(nBufferBytes-i)); nBufferBytes -= i; } } else { nBufferBytes = 0; } } } } /* * openserial * * Open the serial port with the given device name and configure it for * reading NMEA data from a GPS receiver. * * Parameters: * tty : pointer to : A zero-terminated string containing the device * unsigned char name of the appropriate serial port. * blocksz : integer : Block size for port I/O * baud : integer : Baud rate for port I/O * * Return Value: * The function returns a file descriptor for the opened port if successful. * The function returns -1 in the event of an error. * * Remarks: * */ static int openserial(const char * tty, int blocksz, int baud) { int fd; struct termios termios; fd = open(tty, O_RDWR | O_NONBLOCK | O_EXLOCK); if(fd < 0) { perror("ERROR: opening serial connection"); return (-1); } if(tcgetattr(fd, &termios) < 0) { perror("ERROR: get serial attributes"); return (-1); } termios.c_iflag = 0; termios.c_oflag = 0; /* (ONLRET) */ termios.c_cflag = CS8 | CLOCAL | CREAD; termios.c_lflag = 0; { int cnt; for(cnt = 0; cnt < NCCS; cnt++) termios.c_cc[cnt] = -1; } termios.c_cc[VMIN] = blocksz; termios.c_cc[VTIME] = 2; #if (B4800 != 4800) /* * Not every system has speed settings equal to absolute speed value. */ switch (baud) { case 300: baud = B300; break; case 1200: baud = B1200; break; case 2400: baud = B2400; break; case 4800: baud = B4800; break; case 9600: baud = B9600; break; case 19200: baud = B19200; break; case 38400: baud = B38400; break; #ifdef B57600 case 57600: baud = B57600; break; #endif #ifdef B115200 case 115200: baud = B115200; break; #endif #ifdef B230400 case 230400: baud = B230400; break; #endif default: fprintf(stderr, "WARNING: Baud settings not useful, using 19200\n"); baud = B19200; break; } #endif if(cfsetispeed(&termios, baud) != 0) { perror("ERROR: setting serial speed with cfsetispeed"); return (-1); } if(cfsetospeed(&termios, baud) != 0) { perror("ERROR: setting serial speed with cfsetospeed"); return (-1); } if(tcsetattr(fd, TCSANOW, &termios) < 0) { perror("ERROR: setting serial attributes"); return (-1); } if(fcntl(fd, F_SETFL, 0) == -1) { perror("WARNING: setting blocking mode failed"); } return (fd); } /* * usage * * Send a usage message to standard error and quit the program. * * Parameters: * None. * * Return Value: * The function does not return a value. * * Remarks: * */ static #ifdef __GNUC__ __attribute__ ((noreturn)) #endif /* __GNUC__ */ void usage(int rc) { fprintf(stderr, "Usage: %s [OPTIONS]\n", VERSION); fprintf(stderr, " Options are: [-] \n"); fprintf(stderr, " -a DestinationCaster name or address (default: %s)\n", NTRIP_CASTER); fprintf(stderr, " -p DestinationCaster port (default: %d)\n", NTRIP_PORT); fprintf(stderr, " -m DestinationCaster mountpoint\n"); fprintf(stderr, " -c DestinationCaster password\n"); fprintf(stderr, " -h|? print this help screen\n"); fprintf(stderr, " -M sets the input mode\n"); fprintf(stderr, " (1=serial, 2=tcpsocket, 3=file, 4=sisnet" ", 5=udpsocket, 6=caster)\n"); fprintf(stderr, " Mode = file:\n"); fprintf(stderr, " -s file, simulate data stream by reading log file\n"); fprintf(stderr, " default/current setting is %s\n", filepath); fprintf(stderr, " Mode = serial:\n"); fprintf(stderr, " -b baud_rate, sets serial input baud rate\n"); fprintf(stderr, " default/current value is %d\n", ttybaud); fprintf(stderr, " -i input_device, sets name of serial input device\n"); fprintf(stderr, " default/current value is %s\n", ttyport); fprintf(stderr, " (normally a symbolic link to /dev/tty\?\?)\n"); fprintf(stderr, " Mode = tcpsocket or udpsocket:\n"); fprintf(stderr, " -P receiver port (default: %d)\n", SERV_TCP_PORT); fprintf(stderr, " -H hostname of TCP server (default: %s)\n", SERV_HOST_ADDR); fprintf(stderr, " -f initfile send to server\n"); fprintf(stderr, " -B bindmode: bind to incoming UDP stream\n"); fprintf(stderr, " Mode = sisnet:\n"); fprintf(stderr, " -P receiver port (default: %d)\n", SISNET_PORT); fprintf(stderr, " -H hostname of TCP server (default: %s)\n", SISNET_SERVER); fprintf(stderr, " -u username\n"); fprintf(stderr, " -l password\n"); fprintf(stderr, " -V version [2.1, 3.0 or 3.1] (default: 3.1)\n"); fprintf(stderr, " Mode = caster:\n"); fprintf(stderr, " -P SourceCaster port (default: %d)\n", NTRIP_PORT); fprintf(stderr, " -H SourceCaster hostname (default: %s)\n", NTRIP_CASTER); fprintf(stderr, " -D SourceCaster mountpoint\n"); fprintf(stderr, " -U SourceCaster mountpoint username\n"); fprintf(stderr, " -W SourceCaster mountpoint password\n"); fprintf(stderr, "\n"); exit(rc); } static const char encodingTable [64] = { 'A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P', 'Q','R','S','T','U','V','W','X','Y','Z','a','b','c','d','e','f', 'g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v', 'w','x','y','z','0','1','2','3','4','5','6','7','8','9','+','/' }; /* does not buffer overrun, but breaks directly after an error */ /* returns the number of required bytes */ static int encode(char *buf, int size, const char *user, const char *pwd) { unsigned char inbuf[3]; char *out = buf; int i, sep = 0, fill = 0, bytes = 0; while(*user || *pwd) { i = 0; while(i < 3 && *user) inbuf[i++] = *(user++); if(i < 3 && !sep) {inbuf[i++] = ':'; ++sep; } while(i < 3 && *pwd) inbuf[i++] = *(pwd++); while(i < 3) {inbuf[i++] = 0; ++fill; } if(out-buf < size-1) *(out++) = encodingTable[(inbuf [0] & 0xFC) >> 2]; if(out-buf < size-1) *(out++) = encodingTable[((inbuf [0] & 0x03) << 4) | ((inbuf [1] & 0xF0) >> 4)]; if(out-buf < size-1) { if(fill == 2) *(out++) = '='; else *(out++) = encodingTable[((inbuf [1] & 0x0F) << 2) | ((inbuf [2] & 0xC0) >> 6)]; } if(out-buf < size-1) { if(fill >= 1) *(out++) = '='; else *(out++) = encodingTable[inbuf [2] & 0x3F]; } bytes += 4; } if(out-buf < size) *out = 0; return bytes; }