git.distorted.org.uk Git - u/mdw/putty/blob - portfwd.c

   1 #include <windows.h>
   2 #include <stdio.h>
   3 #include <stdlib.h>
   4
   5 #include "putty.h"
   6 #include "ssh.h"
   7
   8 #ifndef FALSE
   9 #define FALSE 0
  10 #endif
  11 #ifndef TRUE
  12 #define TRUE 1
  13 #endif
  14
  15 #define GET_32BIT_LSB_FIRST(cp) \
  16   (((unsigned long)(unsigned char)(cp)[0]) | \
  17   ((unsigned long)(unsigned char)(cp)[1] << 8) | \
  18   ((unsigned long)(unsigned char)(cp)[2] << 16) | \
  19   ((unsigned long)(unsigned char)(cp)[3] << 24))
  20
  21 #define PUT_32BIT_LSB_FIRST(cp, value) ( \
  22   (cp)[0] = (value), \
  23   (cp)[1] = (value) >> 8, \
  24   (cp)[2] = (value) >> 16, \
  25   (cp)[3] = (value) >> 24 )
  26
  27 #define GET_16BIT_LSB_FIRST(cp) \
  28   (((unsigned long)(unsigned char)(cp)[0]) | \
  29   ((unsigned long)(unsigned char)(cp)[1] << 8))
  30
  31 #define PUT_16BIT_LSB_FIRST(cp, value) ( \
  32   (cp)[0] = (value), \
  33   (cp)[1] = (value) >> 8 )
  34
  35 #define GET_32BIT_MSB_FIRST(cp) \
  36   (((unsigned long)(unsigned char)(cp)[0] << 24) | \
  37   ((unsigned long)(unsigned char)(cp)[1] << 16) | \
  38   ((unsigned long)(unsigned char)(cp)[2] << 8) | \
  39   ((unsigned long)(unsigned char)(cp)[3]))
  40
  41 #define PUT_32BIT_MSB_FIRST(cp, value) ( \
  42   (cp)[0] = (value) >> 24, \
  43   (cp)[1] = (value) >> 16, \
  44   (cp)[2] = (value) >> 8, \
  45   (cp)[3] = (value) )
  46
  47 #define GET_16BIT_MSB_FIRST(cp) \
  48   (((unsigned long)(unsigned char)(cp)[0] << 8) | \
  49   ((unsigned long)(unsigned char)(cp)[1]))
  50
  51 #define PUT_16BIT_MSB_FIRST(cp, value) ( \
  52   (cp)[0] = (value) >> 8, \
  53   (cp)[1] = (value) )
  54
  55 struct pfwd_queue {
  56     struct pfwd_queue *next;
  57     char *buf;
  58 };
  59
  60 struct PFwdPrivate {
  61     struct plug_function_table *fn;
  62     /* the above variable absolutely *must* be the first in this structure */
  63     void *c;                           /* (channel) data used by ssh.c */
  64     void *backhandle;                  /* instance of SSH backend itself */
  65     /* Note that backhandle need not be filled in if c is non-NULL */
  66     Socket s;
  67     char hostname[128];
  68     int throttled, throttle_override;
  69     int port;
  70     int ready;
  71     struct pfwd_queue *waiting;
  72 };
  73
  74 void pfd_close(Socket s);
  75
  76
  77 static int pfd_closing(Plug plug, char *error_msg, int error_code,
  78                        int calling_back)
  79 {
  80     struct PFwdPrivate *pr = (struct PFwdPrivate *) plug;
  81
  82     /*
  83      * We have no way to communicate down the forwarded connection,
  84      * so if an error occurred on the socket, we just ignore it
  85      * and treat it like a proper close.
  86      */
  87     sshfwd_close(pr->c);
  88     pfd_close(pr->s);
  89     return 1;
  90 }
  91
  92 static int pfd_receive(Plug plug, int urgent, char *data, int len)
  93 {
  94     struct PFwdPrivate *pr = (struct PFwdPrivate *) plug;
  95     if (pr->ready) {
  96         if (sshfwd_write(pr->c, data, len) > 0) {
  97             pr->throttled = 1;
  98             sk_set_frozen(pr->s, 1);
  99         }
 100     }
 101     return 1;
 102 }
 103
 104 static void pfd_sent(Plug plug, int bufsize)
 105 {
 106     struct PFwdPrivate *pr = (struct PFwdPrivate *) plug;
 107
 108     sshfwd_unthrottle(pr->c, bufsize);
 109 }
 110
 111 /*
 112  * Called when receiving a PORT OPEN from the server
 113  */
 114 char *pfd_newconnect(Socket *s, char *hostname, int port, void *c)
 115 {
 116     static struct plug_function_table fn_table = {
 117         pfd_closing,
 118         pfd_receive,
 119         pfd_sent,
 120         NULL
 121     };
 122
 123     SockAddr addr;
 124     char *err, *dummy_realhost;
 125     struct PFwdPrivate *pr;
 126
 127     /*
 128      * Try to find host.
 129      */
 130     addr = sk_namelookup(hostname, &dummy_realhost);
 131     if ((err = sk_addr_error(addr)))
 132         return err;
 133
 134     /*
 135      * Open socket.
 136      */
 137     pr = (struct PFwdPrivate *) smalloc(sizeof(struct PFwdPrivate));
 138     pr->fn = &fn_table;
 139     pr->throttled = pr->throttle_override = 0;
 140     pr->ready = 1;
 141     pr->c = c;
 142     pr->backhandle = NULL;             /* we shouldn't need this */
 143
 144     pr->s = *s = new_connection(addr, dummy_realhost, port, 0, 1, 0, (Plug) pr);
 145     if ((err = sk_socket_error(*s))) {
 146         sfree(pr);
 147         return err;
 148     }
 149
 150     sk_set_private_ptr(*s, pr);
 151     sk_addr_free(addr);
 152     return NULL;
 153 }
 154
 155 /*
 156  called when someone connects to the local port
 157  */
 158
 159 static int pfd_accepting(Plug p, void *sock)
 160 {
 161     static struct plug_function_table fn_table = {
 162         pfd_closing,
 163         pfd_receive,
 164         pfd_sent,
 165         NULL
 166     };
 167     struct PFwdPrivate *pr, *org;
 168     Socket s;
 169     char *err;
 170
 171     org = (struct PFwdPrivate *)p;
 172     pr = (struct PFwdPrivate *) smalloc(sizeof(struct PFwdPrivate));
 173     pr->fn = &fn_table;
 174
 175     pr->c = NULL;
 176     pr->backhandle = org->backhandle;
 177
 178     pr->s = s = sk_register(sock, (Plug) pr);
 179     if ((err = sk_socket_error(s))) {
 180         sfree(pr);
 181         return err != NULL;
 182     }
 183
 184     pr->c = new_sock_channel(org->backhandle, s);
 185
 186     strcpy(pr->hostname, org->hostname);
 187     pr->port = org->port;
 188     pr->throttled = pr->throttle_override = 0;
 189     pr->ready = 0;
 190     pr->waiting = NULL;
 191
 192     sk_set_private_ptr(s, pr);
 193
 194     if (pr->c == NULL) {
 195         sfree(pr);
 196         return 1;
 197     } else {
 198         /* asks to forward to the specified host/port for this */
 199         ssh_send_port_open(pr->c, pr->hostname, pr->port, "forwarding");
 200     }
 201
 202     return 0;
 203 }
 204
 205
 206 /* Add a new forwarding from port -> desthost:destport
 207  sets up a listener on the local machine on port
 208  */
 209 char *pfd_addforward(char *desthost, int destport, int port, void *backhandle)
 210 {
 211     static struct plug_function_table fn_table = {
 212         pfd_closing,
 213         pfd_receive,                   /* should not happen... */
 214         pfd_sent,                      /* also should not happen */
 215         pfd_accepting
 216     };
 217
 218     char *err;
 219     struct PFwdPrivate *pr;
 220     Socket s;
 221
 222     /*
 223      * Open socket.
 224      */
 225     pr = (struct PFwdPrivate *) smalloc(sizeof(struct PFwdPrivate));
 226     pr->fn = &fn_table;
 227     pr->c = NULL;
 228     strcpy(pr->hostname, desthost);
 229     pr->port = destport;
 230     pr->throttled = pr->throttle_override = 0;
 231     pr->ready = 0;
 232     pr->waiting = NULL;
 233     pr->backhandle = backhandle;
 234
 235     pr->s = s = new_listener(port, (Plug) pr, !cfg.lport_acceptall);
 236     if ((err = sk_socket_error(s))) {
 237         sfree(pr);
 238         return err;
 239     }
 240
 241     sk_set_private_ptr(s, pr);
 242
 243     return NULL;
 244 }
 245
 246 void pfd_close(Socket s)
 247 {
 248     struct PFwdPrivate *pr;
 249
 250     if (!s)
 251         return;
 252
 253     pr = (struct PFwdPrivate *) sk_get_private_ptr(s);
 254
 255     sfree(pr);
 256
 257     sk_close(s);
 258 }
 259
 260 void pfd_unthrottle(Socket s)
 261 {
 262     struct PFwdPrivate *pr;
 263     if (!s)
 264         return;
 265     pr = (struct PFwdPrivate *) sk_get_private_ptr(s);
 266
 267     pr->throttled = 0;
 268     sk_set_frozen(s, pr->throttled || pr->throttle_override);
 269 }
 270
 271 void pfd_override_throttle(Socket s, int enable)
 272 {
 273     struct PFwdPrivate *pr;
 274     if (!s)
 275         return;
 276     pr = (struct PFwdPrivate *) sk_get_private_ptr(s);
 277
 278     pr->throttle_override = enable;
 279     sk_set_frozen(s, pr->throttled || pr->throttle_override);
 280 }
 281
 282 /*
 283  * Called to send data down the raw connection.
 284  */
 285 int pfd_send(Socket s, char *data, int len)
 286 {
 287     if (s == NULL)
 288         return 0;
 289     return sk_write(s, data, len);
 290 }
 291
 292
 293 void pfd_confirm(Socket s)
 294 {
 295     struct PFwdPrivate *pr;
 296
 297     if (s == NULL)
 298         return;
 299
 300     pr = (struct PFwdPrivate *) sk_get_private_ptr(s);
 301     pr->ready = 1;
 302     sk_set_frozen(s, 0);
 303     sk_write(s, NULL, 0);
 304 }