citadel/clientsocket.c

   1 /*
   2  * $Id$
   3  *
   4  * This module handles client-side sockets opened by the Citadel server (for
   5  * the client side of Internet protocols, etc.)   It does _not_ handle client
   6  * sockets for the Citadel client; for that you must look in ipc_c_tcp.c
   7  * (which, uncoincidentally, bears a striking similarity to this file).
   8  *
   9  */
  10
  11 #include "sysdep.h"
  12 #include <stdlib.h>
  13 #include <unistd.h>
  14 #include <stdio.h>
  15 #include <signal.h>
  16 #include <sys/types.h>
  17 #include <sys/time.h>
  18 #include <sys/socket.h>
  19 #include <netinet/in.h>
  20 #include <arpa/inet.h>
  21 #include <netdb.h>
  22 #include <string.h>
  23 #include <pwd.h>
  24 #include <errno.h>
  25 #include <stdarg.h>
  26 #include <libcitadel.h>
  27 #include "citadel.h"
  28 #include "server.h"
  29 #ifndef HAVE_SNPRINTF
  30 #include "snprintf.h"
  31 #endif
  32 #include "sysdep_decls.h"
  33 #include "config.h"
  34 #include "clientsocket.h"
  35
  36 #ifndef INADDR_NONE
  37 #define INADDR_NONE 0xffffffff
  38 #endif
  39
  40 int sock_connect(char *host, char *service, char *protocol)
  41 {
  42         struct hostent *phe;
  43         struct servent *pse;
  44         struct protoent *ppe;
  45         struct sockaddr_in sin;
  46         struct sockaddr_in egress_sin;
  47         int s, type;
  48
  49         if ((host == NULL) || IsEmptyStr(host))
  50                 return(-1);
  51         if ((service == NULL) || IsEmptyStr(service))
  52                 return(-1);
  53         if ((protocol == NULL) || IsEmptyStr(protocol))
  54                 return(-1);
  55
  56         memset(&sin, 0, sizeof(sin));
  57         sin.sin_family = AF_INET;
  58
  59         pse = getservbyname(service, protocol);
  60         if (pse) {
  61                 sin.sin_port = pse->s_port;
  62         } else if ((sin.sin_port = htons((u_short) atoi(service))) == 0) {
  63                 CtdlLogPrintf(CTDL_CRIT, "Can't get %s service entry: %s\n",
  64                         service, strerror(errno));
  65                 return(-1);
  66         }
  67         phe = gethostbyname(host);
  68         if (phe) {
  69                 memcpy(&sin.sin_addr, phe->h_addr, phe->h_length);
  70         } else if ((sin.sin_addr.s_addr = inet_addr(host)) == INADDR_NONE) {
  71                 CtdlLogPrintf(CTDL_ERR, "Can't get %s host entry: %s\n",
  72                         host, strerror(errno));
  73                 return(-1);
  74         }
  75         if ((ppe = getprotobyname(protocol)) == 0) {
  76                 CtdlLogPrintf(CTDL_CRIT, "Can't get %s protocol entry: %s\n",
  77                         protocol, strerror(errno));
  78                 return(-1);
  79         }
  80         if (!strcmp(protocol, "udp")) {
  81                 type = SOCK_DGRAM;
  82         } else {
  83                 type = SOCK_STREAM;
  84         }
  85
  86         s = socket(PF_INET, type, ppe->p_proto);
  87         if (s < 0) {
  88                 CtdlLogPrintf(CTDL_CRIT, "Can't create socket: %s\n", strerror(errno));
  89                 return(-1);
  90         }
  91
  92         /* If citserver is bound to a specific IP address on the host, make
  93          * sure we use that address for outbound connections.
  94          */
  95         memset(&egress_sin, 0, sizeof(egress_sin));
  96         egress_sin.sin_family = AF_INET;
  97         if (!IsEmptyStr(config.c_ip_addr)) {
  98                 egress_sin.sin_addr.s_addr = inet_addr(config.c_ip_addr);
  99                 if (egress_sin.sin_addr.s_addr == !INADDR_ANY) {
 100                         egress_sin.sin_addr.s_addr = INADDR_ANY;
 101                 }
 102
 103                 /* If this bind fails, no problem; we can still use INADDR_ANY */
 104                 bind(s, (struct sockaddr *)&egress_sin, sizeof(egress_sin));
 105         }
 106
 107         /* Now try to connect to the remote host. */
 108         if (connect(s, (struct sockaddr *) &sin, sizeof(sin)) < 0) {
 109                 CtdlLogPrintf(CTDL_ERR, "Can't connect to %s:%s: %s\n",
 110                         host, service, strerror(errno));
 111                 close(s);
 112                 return(-1);
 113         }
 114
 115         return (s);
 116 }
 117
 118
 119
 120 /*
 121  * sock_read_to() - input binary data from socket, with a settable timeout.
 122  * Returns the number of bytes read, or -1 for error.
 123  * If keep_reading_until_full is nonzero, we keep reading until we get the number of requested bytes
 124  */
 125 int sock_read_to(int sock, char *buf, int bytes, int timeout, int keep_reading_until_full)
 126 {
 127         int len,rlen;
 128         fd_set rfds;
 129         struct timeval tv;
 130         int retval;
 131
 132         len = 0;
 133         while (len<bytes) {
 134                 FD_ZERO(&rfds);
 135                 FD_SET(sock, &rfds);
 136                 tv.tv_sec = timeout;
 137                 tv.tv_usec = 0;
 138
 139                 retval = select(sock+1, &rfds, NULL, NULL, &tv);
 140
 141                 if (FD_ISSET(sock, &rfds) == 0) {       /* timed out */
 142                         CtdlLogPrintf(CTDL_ERR, "sock_read() timed out.\n");
 143                         return(-1);
 144                 }
 145
 146                 rlen = read(sock, &buf[len], bytes-len);
 147                 if (rlen<1) {
 148                         CtdlLogPrintf(CTDL_ERR, "sock_read() failed: %s\n",
 149                                 strerror(errno));
 150                         return(-1);
 151                 }
 152                 len = len + rlen;
 153                 if (!keep_reading_until_full) return(len);
 154         }
 155         return(bytes);
 156 }
 157
 158
 159 /*
 160  * sock_read() - input binary data from socket.
 161  * Returns the number of bytes read, or -1 for error.
 162  */
 163 INLINE int sock_read(int sock, char *buf, int bytes, int keep_reading_until_full)
 164 {
 165         return sock_read_to(sock, buf, bytes, CLIENT_TIMEOUT, keep_reading_until_full);
 166 }
 167
 168
 169 /*
 170  * sock_write() - send binary to server.
 171  * Returns the number of bytes written, or -1 for error.
 172  */
 173 int sock_write(int sock, char *buf, int nbytes)
 174 {
 175         int bytes_written = 0;
 176         int retval;
 177         while (bytes_written < nbytes) {
 178                 retval = write(sock, &buf[bytes_written],
 179                                nbytes - bytes_written);
 180                 if (retval < 1) {
 181                         return (-1);
 182                 }
 183                 bytes_written = bytes_written + retval;
 184         }
 185         return (bytes_written);
 186 }
 187
 188
 189
 190 /*
 191  * Input string from socket - implemented in terms of sock_read()
 192  *
 193  */
 194 int sock_getln(int sock, char *buf, int bufsize)
 195 {
 196         int i;
 197
 198         /* Read one character at a time.
 199          */
 200         for (i = 0;; i++) {
 201                 if (sock_read(sock, &buf[i], 1, 1) < 0) return(-1);
 202                 if (buf[i] == '\n' || i == (bufsize-1))
 203                         break;
 204         }
 205
 206         /* If we got a long line, discard characters until the newline.
 207          */
 208         if (i == (bufsize-1))
 209                 while (buf[i] != '\n')
 210                         if (sock_read(sock, &buf[i], 1, 1) < 0) return(-1);
 211
 212         /* Strip any trailing CR and LF characters.
 213          */
 214         buf[i] = 0;
 215         while ( (i > 0)
 216                 && ( (buf[i - 1]==13)
 217                      || ( buf[i - 1]==10)) ) {
 218                 i--;
 219                 buf[i] = 0;
 220         }
 221         return(i);
 222 }
 223
 224 /*
 225  * Multiline version of sock_gets() ... this is a convenience function for
 226  * client side protocol implementations.  It only returns the first line of
 227  * a multiline response, discarding the rest.
 228  */
 229 int ml_sock_gets(int sock, char *buf) {
 230         char bigbuf[1024];
 231         int g;
 232
 233         g = sock_getln(sock, buf, SIZ);
 234         if (g < 4) return(g);
 235         if (buf[3] != '-') return(g);
 236
 237         do {
 238                 g = sock_getln(sock, bigbuf, SIZ);
 239                 if (g < 0) return(g);
 240         } while ( (g >= 4) && (bigbuf[3] == '-') );
 241
 242         return(strlen(buf));
 243 }
 244
 245
 246 /*
 247  * sock_puts() - send line to server - implemented in terms of serv_write()
 248  * Returns the number of bytes written, or -1 for error.
 249  */
 250 int sock_puts(int sock, char *buf)
 251 {
 252         int i, j;
 253
 254         i = sock_write(sock, buf, strlen(buf));
 255         if (i<0) return(i);
 256         j = sock_write(sock, "\n", 1);
 257         if (j<0) return(j);
 258         return(i+j);
 259 }