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     Socket s;
  65     char hostname[128];
  66     int throttled, throttle_override;
  67     int port;
  68     int ready;
  69     struct pfwd_queue *waiting;
  70 };
  71
  72 void pfd_close(Socket s);
  73
  74
  75 static int pfd_closing(Plug plug, char *error_msg, int error_code,
  76                        int calling_back)
  77 {
  78     struct PFwdPrivate *pr = (struct PFwdPrivate *) plug;
  79
  80     /*
  81      * We have no way to communicate down the forwarded connection,
  82      * so if an error occurred on the socket, we just ignore it
  83      * and treat it like a proper close.
  84      */
  85     sshfwd_close(pr->c);
  86     pfd_close(pr->s);
  87     return 1;
  88 }
  89
  90 static int pfd_receive(Plug plug, int urgent, char *data, int len)
  91 {
  92     struct PFwdPrivate *pr = (struct PFwdPrivate *) plug;
  93     if (pr->ready) {
  94         if (sshfwd_write(pr->c, data, len) > 0) {
  95             pr->throttled = 1;
  96             sk_set_frozen(pr->s, 1);
  97         }
  98     }
  99     return 1;
 100 }
 101
 102 static void pfd_sent(Plug plug, int bufsize)
 103 {
 104     struct PFwdPrivate *pr = (struct PFwdPrivate *) plug;
 105
 106     sshfwd_unthrottle(pr->c, bufsize);
 107 }
 108
 109 /*
 110  * Called when receiving a PORT OPEN from the server
 111  */
 112 char *pfd_newconnect(Socket *s, char *hostname, int port, void *c)
 113 {
 114     static 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 = sk_namelookup(hostname, &dummy_realhost);
 129     if ((err = sk_addr_error(addr)))
 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
 141     pr->s = *s = sk_new(addr, port, 0, 1, (Plug) pr);
 142     if ((err = sk_socket_error(*s))) {
 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, struct sockaddr *addr, void *sock)
 157 {
 158     /* for now always accept this socket */
 159     static struct plug_function_table fn_table = {
 160         pfd_closing,
 161         pfd_receive,
 162         pfd_sent,
 163         NULL
 164     };
 165     struct PFwdPrivate *pr, *org;
 166     struct sockaddr_in *sin = (struct sockaddr_in *)addr;
 167     Socket s;
 168     char *err;
 169
 170     if (ntohl(sin->sin_addr.s_addr) != 0x7F000001 && !cfg.lport_acceptall)
 171         return 1; /* denied */
 172
 173     org = (struct PFwdPrivate *)p;
 174     pr = (struct PFwdPrivate *) smalloc(sizeof(struct PFwdPrivate));
 175     pr->fn = &fn_table;
 176
 177     pr->c = NULL;
 178
 179     pr->s = s = sk_register(sock, (Plug) pr);
 180     if ((err = sk_socket_error(s))) {
 181         sfree(pr);
 182         return err != NULL;
 183     }
 184
 185     pr->c = new_sock_channel(s);
 186
 187     strcpy(pr->hostname, org->hostname);
 188     pr->port = org->port;
 189     pr->throttled = pr->throttle_override = 0;
 190     pr->ready = 0;
 191     pr->waiting = NULL;
 192
 193     sk_set_private_ptr(s, pr);
 194
 195     if (pr->c == NULL) {
 196         sfree(pr);
 197         return 1;
 198     } else {
 199         /* asks to forward to the specified host/port for this */
 200         ssh_send_port_open(pr->c, pr->hostname, pr->port, "forwarding");
 201     }
 202
 203     return 0;
 204 }
 205
 206
 207 /* Add a new forwarding from port -> desthost:destport
 208  sets up a listenner on the local machine on port
 209  */
 210 char *pfd_addforward(char *desthost, int destport, int port)
 211 {
 212     static struct plug_function_table fn_table = {
 213         pfd_closing,
 214         pfd_receive,                   /* should not happen... */
 215         pfd_sent,                      /* also should not happen */
 216         pfd_accepting
 217     };
 218
 219     char *err;
 220     struct PFwdPrivate *pr;
 221     Socket s;
 222
 223     /*
 224      * Open socket.
 225      */
 226     pr = (struct PFwdPrivate *) smalloc(sizeof(struct PFwdPrivate));
 227     pr->fn = &fn_table;
 228     pr->c = NULL;
 229     strcpy(pr->hostname, desthost);
 230     pr->port = destport;
 231     pr->throttled = pr->throttle_override = 0;
 232     pr->ready = 0;
 233     pr->waiting = NULL;
 234
 235     pr->s = s = sk_newlistenner(port, (Plug) pr);
 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 }