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     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 {
 113     static struct plug_function_table fn_table = {
 114         pfd_closing,
 115         pfd_receive,
 116         pfd_sent,
 117         NULL
 118     };
 119
 120     SockAddr addr;
 121     char *err, *dummy_realhost;
 122     struct PFwdPrivate *pr;
 123
 124     /*
 125      * Try to find host.
 126      */
 127     addr = name_lookup(hostname, port, &dummy_realhost);
 128     if ((err = sk_addr_error(addr)) != NULL)
 129         return err;
 130
 131     /*
 132      * Open socket.
 133      */
 134     pr = (struct PFwdPrivate *) smalloc(sizeof(struct PFwdPrivate));
 135     pr->fn = &fn_table;
 136     pr->throttled = pr->throttle_override = 0;
 137     pr->ready = 1;
 138     pr->c = c;
 139     pr->backhandle = NULL;             /* we shouldn't need this */
 140
 141     pr->s = *s = new_connection(addr, dummy_realhost, port, 0, 1, 0, (Plug) pr);
 142     if ((err = sk_socket_error(*s)) != NULL) {
 143         sfree(pr);
 144         return err;
 145     }
 146
 147     sk_set_private_ptr(*s, pr);
 148     sk_addr_free(addr);
 149     return NULL;
 150 }
 151
 152 /*
 153  called when someone connects to the local port
 154  */
 155
 156 static int pfd_accepting(Plug p, void *sock)
 157 {
 158     static struct plug_function_table fn_table = {
 159         pfd_closing,
 160         pfd_receive,
 161         pfd_sent,
 162         NULL
 163     };
 164     struct PFwdPrivate *pr, *org;
 165     Socket s;
 166     char *err;
 167
 168     org = (struct PFwdPrivate *)p;
 169     pr = (struct PFwdPrivate *) smalloc(sizeof(struct PFwdPrivate));
 170     pr->fn = &fn_table;
 171
 172     pr->c = NULL;
 173     pr->backhandle = org->backhandle;
 174
 175     pr->s = s = sk_register(sock, (Plug) pr);
 176     if ((err = sk_socket_error(s)) != NULL) {
 177         sfree(pr);
 178         return err != NULL;
 179     }
 180
 181     pr->c = new_sock_channel(org->backhandle, s);
 182
 183     strcpy(pr->hostname, org->hostname);
 184     pr->port = org->port;
 185     pr->throttled = pr->throttle_override = 0;
 186     pr->ready = 0;
 187     pr->waiting = NULL;
 188
 189     sk_set_private_ptr(s, pr);
 190
 191     if (pr->c == NULL) {
 192         sfree(pr);
 193         return 1;
 194     } else {
 195         /* asks to forward to the specified host/port for this */
 196         ssh_send_port_open(pr->c, pr->hostname, pr->port, "forwarding");
 197     }
 198
 199     return 0;
 200 }
 201
 202
 203 /* Add a new forwarding from port -> desthost:destport
 204  sets up a listener on the local machine on (srcaddr:)port
 205  */
 206 char *pfd_addforward(char *desthost, int destport, char *srcaddr, int port,
 207                      void *backhandle)
 208 {
 209     static struct plug_function_table fn_table = {
 210         pfd_closing,
 211         pfd_receive,                   /* should not happen... */
 212         pfd_sent,                      /* also should not happen */
 213         pfd_accepting
 214     };
 215
 216     char *err;
 217     struct PFwdPrivate *pr;
 218     Socket s;
 219
 220     /*
 221      * Open socket.
 222      */
 223     pr = (struct PFwdPrivate *) smalloc(sizeof(struct PFwdPrivate));
 224     pr->fn = &fn_table;
 225     pr->c = NULL;
 226     strcpy(pr->hostname, desthost);
 227     pr->port = destport;
 228     pr->throttled = pr->throttle_override = 0;
 229     pr->ready = 0;
 230     pr->waiting = NULL;
 231     pr->backhandle = backhandle;
 232
 233     pr->s = s = new_listener(srcaddr, port, (Plug) pr, !cfg.lport_acceptall);
 234     if ((err = sk_socket_error(s)) != NULL) {
 235         sfree(pr);
 236         return err;
 237     }
 238
 239     sk_set_private_ptr(s, pr);
 240
 241     return NULL;
 242 }
 243
 244 void pfd_close(Socket s)
 245 {
 246     struct PFwdPrivate *pr;
 247
 248     if (!s)
 249         return;
 250
 251     pr = (struct PFwdPrivate *) sk_get_private_ptr(s);
 252
 253     sfree(pr);
 254
 255     sk_close(s);
 256 }
 257
 258 void pfd_unthrottle(Socket s)
 259 {
 260     struct PFwdPrivate *pr;
 261     if (!s)
 262         return;
 263     pr = (struct PFwdPrivate *) sk_get_private_ptr(s);
 264
 265     pr->throttled = 0;
 266     sk_set_frozen(s, pr->throttled || pr->throttle_override);
 267 }
 268
 269 void pfd_override_throttle(Socket s, int enable)
 270 {
 271     struct PFwdPrivate *pr;
 272     if (!s)
 273         return;
 274     pr = (struct PFwdPrivate *) sk_get_private_ptr(s);
 275
 276     pr->throttle_override = enable;
 277     sk_set_frozen(s, pr->throttled || pr->throttle_override);
 278 }
 279
 280 /*
 281  * Called to send data down the raw connection.
 282  */
 283 int pfd_send(Socket s, char *data, int len)
 284 {
 285     if (s == NULL)
 286         return 0;
 287     return sk_write(s, data, len);
 288 }
 289
 290
 291 void pfd_confirm(Socket s)
 292 {
 293     struct PFwdPrivate *pr;
 294
 295     if (s == NULL)
 296         return;
 297
 298     pr = (struct PFwdPrivate *) sk_get_private_ptr(s);
 299     pr->ready = 1;
 300     sk_set_frozen(s, 0);
 301     sk_write(s, NULL, 0);
 302 }