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

   1 #include <stdio.h>
   2 #include <stdlib.h>
   3
   4 #include "putty.h"
   5 #include "ssh.h"
   6
   7 #ifndef FALSE
   8 #define FALSE 0
   9 #endif
  10 #ifndef TRUE
  11 #define TRUE 1
  12 #endif
  13
  14 #define GET_32BIT_LSB_FIRST(cp) \
  15   (((unsigned long)(unsigned char)(cp)[0]) | \
  16   ((unsigned long)(unsigned char)(cp)[1] << 8) | \
  17   ((unsigned long)(unsigned char)(cp)[2] << 16) | \
  18   ((unsigned long)(unsigned char)(cp)[3] << 24))
  19
  20 #define PUT_32BIT_LSB_FIRST(cp, value) ( \
  21   (cp)[0] = (value), \
  22   (cp)[1] = (value) >> 8, \
  23   (cp)[2] = (value) >> 16, \
  24   (cp)[3] = (value) >> 24 )
  25
  26 #define GET_16BIT_LSB_FIRST(cp) \
  27   (((unsigned long)(unsigned char)(cp)[0]) | \
  28   ((unsigned long)(unsigned char)(cp)[1] << 8))
  29
  30 #define PUT_16BIT_LSB_FIRST(cp, value) ( \
  31   (cp)[0] = (value), \
  32   (cp)[1] = (value) >> 8 )
  33
  34 #define GET_32BIT_MSB_FIRST(cp) \
  35   (((unsigned long)(unsigned char)(cp)[0] << 24) | \
  36   ((unsigned long)(unsigned char)(cp)[1] << 16) | \
  37   ((unsigned long)(unsigned char)(cp)[2] << 8) | \
  38   ((unsigned long)(unsigned char)(cp)[3]))
  39
  40 #define PUT_32BIT_MSB_FIRST(cp, value) ( \
  41   (cp)[0] = (value) >> 24, \
  42   (cp)[1] = (value) >> 16, \
  43   (cp)[2] = (value) >> 8, \
  44   (cp)[3] = (value) )
  45
  46 #define GET_16BIT_MSB_FIRST(cp) \
  47   (((unsigned long)(unsigned char)(cp)[0] << 8) | \
  48   ((unsigned long)(unsigned char)(cp)[1]))
  49
  50 #define PUT_16BIT_MSB_FIRST(cp, value) ( \
  51   (cp)[0] = (value) >> 8, \
  52   (cp)[1] = (value) )
  53
  54 struct pfwd_queue {
  55     struct pfwd_queue *next;
  56     char *buf;
  57 };
  58
  59 struct PFwdPrivate {
  60     const struct plug_function_table *fn;
  61     /* the above variable absolutely *must* be the first in this structure */
  62     void *c;                           /* (channel) data used by ssh.c */
  63     void *backhandle;                  /* instance of SSH backend itself */
  64     /* Note that backhandle need not be filled in if c is non-NULL */
  65     Socket s;
  66     char hostname[128];
  67     int throttled, throttle_override;
  68     int port;
  69     int ready;
  70     struct pfwd_queue *waiting;
  71 };
  72
  73
  74 static int pfd_closing(Plug plug, char *error_msg, int error_code,
  75                        int calling_back)
  76 {
  77     struct PFwdPrivate *pr = (struct PFwdPrivate *) plug;
  78
  79     /*
  80      * We have no way to communicate down the forwarded connection,
  81      * so if an error occurred on the socket, we just ignore it
  82      * and treat it like a proper close.
  83      */
  84     sshfwd_close(pr->c);
  85     pfd_close(pr->s);
  86     return 1;
  87 }
  88
  89 static int pfd_receive(Plug plug, int urgent, char *data, int len)
  90 {
  91     struct PFwdPrivate *pr = (struct PFwdPrivate *) plug;
  92     if (pr->ready) {
  93         if (sshfwd_write(pr->c, data, len) > 0) {
  94             pr->throttled = 1;
  95             sk_set_frozen(pr->s, 1);
  96         }
  97     }
  98     return 1;
  99 }
 100
 101 static void pfd_sent(Plug plug, int bufsize)
 102 {
 103     struct PFwdPrivate *pr = (struct PFwdPrivate *) plug;
 104
 105     sshfwd_unthrottle(pr->c, bufsize);
 106 }
 107
 108 /*
 109  * Called when receiving a PORT OPEN from the server
 110  */
 111 char *pfd_newconnect(Socket *s, char *hostname, int port, void *c,
 112                      const Config *cfg)
 113 {
 114     static const struct plug_function_table fn_table = {
 115         pfd_closing,
 116         pfd_receive,
 117         pfd_sent,
 118         NULL
 119     };
 120
 121     SockAddr addr;
 122     char *err, *dummy_realhost;
 123     struct PFwdPrivate *pr;
 124
 125     /*
 126      * Try to find host.
 127      */
 128     addr = name_lookup(hostname, port, &dummy_realhost, cfg);
 129     if ((err = sk_addr_error(addr)) != NULL)
 130         return err;
 131
 132     /*
 133      * Open socket.
 134      */
 135     pr = (struct PFwdPrivate *) smalloc(sizeof(struct PFwdPrivate));
 136     pr->fn = &fn_table;
 137     pr->throttled = pr->throttle_override = 0;
 138     pr->ready = 1;
 139     pr->c = c;
 140     pr->backhandle = NULL;             /* we shouldn't need this */
 141
 142     pr->s = *s = new_connection(addr, dummy_realhost, port,
 143                                 0, 1, 0, (Plug) pr, cfg);
 144     if ((err = sk_socket_error(*s)) != NULL) {
 145         sfree(pr);
 146         return err;
 147     }
 148
 149     sk_set_private_ptr(*s, pr);
 150     sk_addr_free(addr);
 151     return NULL;
 152 }
 153
 154 /*
 155  called when someone connects to the local port
 156  */
 157
 158 static int pfd_accepting(Plug p, void *sock)
 159 {
 160     static const struct plug_function_table fn_table = {
 161         pfd_closing,
 162         pfd_receive,
 163         pfd_sent,
 164         NULL
 165     };
 166     struct PFwdPrivate *pr, *org;
 167     Socket s;
 168     char *err;
 169
 170     org = (struct PFwdPrivate *)p;
 171     pr = (struct PFwdPrivate *) smalloc(sizeof(struct PFwdPrivate));
 172     pr->fn = &fn_table;
 173
 174     pr->c = NULL;
 175     pr->backhandle = org->backhandle;
 176
 177     pr->s = s = sk_register(sock, (Plug) pr);
 178     if ((err = sk_socket_error(s)) != NULL) {
 179         sfree(pr);
 180         return err != NULL;
 181     }
 182
 183     pr->c = new_sock_channel(org->backhandle, s);
 184
 185     strcpy(pr->hostname, org->hostname);
 186     pr->port = org->port;
 187     pr->throttled = pr->throttle_override = 0;
 188     pr->ready = 0;
 189     pr->waiting = NULL;
 190
 191     sk_set_private_ptr(s, pr);
 192
 193     if (pr->c == NULL) {
 194         sfree(pr);
 195         return 1;
 196     } else {
 197         /* asks to forward to the specified host/port for this */
 198         ssh_send_port_open(pr->c, pr->hostname, pr->port, "forwarding");
 199     }
 200
 201     return 0;
 202 }
 203
 204
 205 /* Add a new forwarding from port -> desthost:destport
 206  sets up a listener on the local machine on (srcaddr:)port
 207  */
 208 char *pfd_addforward(char *desthost, int destport, char *srcaddr, int port,
 209                      void *backhandle, const Config *cfg)
 210 {
 211     static const 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(srcaddr, port, (Plug) pr,
 236                              !cfg->lport_acceptall, cfg);
 237     if ((err = sk_socket_error(s)) != NULL) {
 238         sfree(pr);
 239         return err;
 240     }
 241
 242     sk_set_private_ptr(s, pr);
 243
 244     return NULL;
 245 }
 246
 247 void pfd_close(Socket s)
 248 {
 249     struct PFwdPrivate *pr;
 250
 251     if (!s)
 252         return;
 253
 254     pr = (struct PFwdPrivate *) sk_get_private_ptr(s);
 255
 256     sfree(pr);
 257
 258     sk_close(s);
 259 }
 260
 261 void pfd_unthrottle(Socket s)
 262 {
 263     struct PFwdPrivate *pr;
 264     if (!s)
 265         return;
 266     pr = (struct PFwdPrivate *) sk_get_private_ptr(s);
 267
 268     pr->throttled = 0;
 269     sk_set_frozen(s, pr->throttled || pr->throttle_override);
 270 }
 271
 272 void pfd_override_throttle(Socket s, int enable)
 273 {
 274     struct PFwdPrivate *pr;
 275     if (!s)
 276         return;
 277     pr = (struct PFwdPrivate *) sk_get_private_ptr(s);
 278
 279     pr->throttle_override = enable;
 280     sk_set_frozen(s, pr->throttled || pr->throttle_override);
 281 }
 282
 283 /*
 284  * Called to send data down the raw connection.
 285  */
 286 int pfd_send(Socket s, char *data, int len)
 287 {
 288     if (s == NULL)
 289         return 0;
 290     return sk_write(s, data, len);
 291 }
 292
 293
 294 void pfd_confirm(Socket s)
 295 {
 296     struct PFwdPrivate *pr;
 297
 298     if (s == NULL)
 299         return;
 300
 301     pr = (struct PFwdPrivate *) sk_get_private_ptr(s);
 302     pr->ready = 1;
 303     sk_set_frozen(s, 0);
 304     sk_write(s, NULL, 0);
 305 }