X-Git-Url: https://git.distorted.org.uk/~mdw/sgt/putty/blobdiff_plain/4797387cf55f5bb018a64e0e6178c3cac931b64c..3ee4eedaec9cad4b5b2ff0f40567fa2e57a942a9:/portfwd.c diff --git a/portfwd.c b/portfwd.c index e21ed3a2..39ff5972 100644 --- a/portfwd.c +++ b/portfwd.c @@ -1,3 +1,7 @@ +/* + * SSH port forwarding. + */ + #include #include @@ -11,46 +15,6 @@ #define TRUE 1 #endif -#define GET_32BIT_LSB_FIRST(cp) \ - (((unsigned long)(unsigned char)(cp)[0]) | \ - ((unsigned long)(unsigned char)(cp)[1] << 8) | \ - ((unsigned long)(unsigned char)(cp)[2] << 16) | \ - ((unsigned long)(unsigned char)(cp)[3] << 24)) - -#define PUT_32BIT_LSB_FIRST(cp, value) ( \ - (cp)[0] = (value), \ - (cp)[1] = (value) >> 8, \ - (cp)[2] = (value) >> 16, \ - (cp)[3] = (value) >> 24 ) - -#define GET_16BIT_LSB_FIRST(cp) \ - (((unsigned long)(unsigned char)(cp)[0]) | \ - ((unsigned long)(unsigned char)(cp)[1] << 8)) - -#define PUT_16BIT_LSB_FIRST(cp, value) ( \ - (cp)[0] = (value), \ - (cp)[1] = (value) >> 8 ) - -#define GET_32BIT_MSB_FIRST(cp) \ - (((unsigned long)(unsigned char)(cp)[0] << 24) | \ - ((unsigned long)(unsigned char)(cp)[1] << 16) | \ - ((unsigned long)(unsigned char)(cp)[2] << 8) | \ - ((unsigned long)(unsigned char)(cp)[3])) - -#define PUT_32BIT_MSB_FIRST(cp, value) ( \ - (cp)[0] = (value) >> 24, \ - (cp)[1] = (value) >> 16, \ - (cp)[2] = (value) >> 8, \ - (cp)[3] = (value) ) - -#define GET_16BIT_MSB_FIRST(cp) \ - (((unsigned long)(unsigned char)(cp)[0] << 8) | \ - ((unsigned long)(unsigned char)(cp)[1])) - -#define PUT_16BIT_MSB_FIRST(cp, value) ( \ - (cp)[0] = (value) >> 8, \ - (cp)[1] = (value) ) - struct PFwdPrivate { const struct plug_function_table *fn; /* the above variable absolutely *must* be the first in this structure */ @@ -86,19 +50,31 @@ struct PFwdPrivate { int buflen; }; -static int pfd_closing(Plug plug, char *error_msg, int error_code, +static void pfd_log(Plug plug, int type, SockAddr addr, int port, + const char *error_msg, int error_code) +{ + /* we have to dump these since we have no interface to logging.c */ +} + +static int pfd_closing(Plug plug, const char *error_msg, int error_code, int calling_back) { struct PFwdPrivate *pr = (struct PFwdPrivate *) plug; - /* - * We have no way to communicate down the forwarded connection, - * so if an error occurred on the socket, we just ignore it - * and treat it like a proper close. - */ - if (pr->c) - sshfwd_close(pr->c); - pfd_close(pr->s); + if (error_msg) { + /* + * Socket error. Slam the connection instantly shut. + */ + sshfwd_unclean_close(pr->c); + } else { + /* + * Ordinary EOF received on socket. Send an EOF on the SSH + * channel. + */ + if (pr->c) + sshfwd_write_eof(pr->c); + } + return 1; } @@ -107,7 +83,12 @@ static int pfd_receive(Plug plug, int urgent, char *data, int len) struct PFwdPrivate *pr = (struct PFwdPrivate *) plug; if (pr->dynamic) { while (len--) { + /* + * Throughout SOCKS negotiation, "hostname" is re-used as a + * random protocol buffer with "port" storing the length. + */ if (pr->port >= lenof(pr->hostname)) { + /* Request too long. */ if ((pr->dynamic >> 12) == 4) { /* Send back a SOCKS 4 error before closing. */ char data[8]; @@ -133,6 +114,7 @@ static int pfd_receive(Plug plug, int urgent, char *data, int len) pr->dynamic = 0x4000; if (pr->port < 2) continue;/* don't have command code yet */ if (pr->hostname[1] != 1) { + /* Not CONNECT. */ /* Send back a SOCKS 4 error before closing. */ char data[8]; memset(data, 0, sizeof(data)); @@ -141,9 +123,9 @@ static int pfd_receive(Plug plug, int urgent, char *data, int len) pfd_close(pr->s); return 1; } - if (pr->port < 8) continue; /* haven't started username */ + if (pr->port <= 8) continue; /* haven't started user/hostname */ if (pr->hostname[pr->port-1] != 0) - continue; /* haven't _finished_ username */ + continue; /* haven't _finished_ user/hostname */ /* * Now we have a full SOCKS 4 request. Check it to * see if it's a SOCKS 4A request. @@ -165,7 +147,7 @@ static int pfd_receive(Plug plug, int urgent, char *data, int len) pr->hostname[0] = 0; /* reply version code */ pr->hostname[1] = 90; /* request granted */ sk_write(pr->s, pr->hostname, 8); - len= pr->port; + len= pr->port - 8; pr->port = GET_16BIT_MSB_FIRST(pr->hostname+2); memmove(pr->hostname, pr->hostname + 8, len); goto connect; @@ -220,7 +202,23 @@ static int pfd_receive(Plug plug, int urgent, char *data, int len) } if (pr->dynamic == 0x5001) { + /* + * We're receiving a SOCKS request. + */ + unsigned char reply[10]; /* SOCKS5 atyp=1 reply */ int atype, alen = 0; + + /* + * Pre-fill reply packet. + * In all cases, we set BND.{HOST,ADDR} to 0.0.0.0:0 + * (atyp=1) in the reply; if we succeed, we don't know + * the right answers, and if we fail, they should be + * ignored. + */ + memset(reply, 0, lenof(reply)); + reply[0] = 5; /* VER */ + reply[3] = 1; /* ATYP = 1 (IPv4, 0.0.0.0:0) */ + if (pr->port < 6) continue; atype = (unsigned char)pr->hostname[3]; if (atype == 1) /* IPv4 address */ @@ -231,9 +229,9 @@ static int pfd_receive(Plug plug, int urgent, char *data, int len) alen = 1 + (unsigned char)pr->hostname[4]; if (pr->port < 6 + alen) continue; if (pr->hostname[1] != 1 || pr->hostname[2] != 0) { - pr->hostname[1] = 1; /* generic failure */ - pr->hostname[2] = 0; /* reserved */ - sk_write(pr->s, pr->hostname, pr->port); + /* Not CONNECT or reserved field nonzero - error */ + reply[1] = 1; /* generic failure */ + sk_write(pr->s, (char *) reply, lenof(reply)); pfd_close(pr->s); return 1; } @@ -243,8 +241,8 @@ static int pfd_receive(Plug plug, int urgent, char *data, int len) */ pr->port = GET_16BIT_MSB_FIRST(pr->hostname+4+alen); if (atype == 1) { - pr->hostname[1] = 0; /* succeeded */ - sk_write(pr->s, pr->hostname, alen + 6); + /* REP=0 (success) already */ + sk_write(pr->s, (char *) reply, lenof(reply)); sprintf(pr->hostname, "%d.%d.%d.%d", (unsigned char)pr->hostname[4], (unsigned char)pr->hostname[5], @@ -252,8 +250,8 @@ static int pfd_receive(Plug plug, int urgent, char *data, int len) (unsigned char)pr->hostname[7]); goto connect; } else if (atype == 3) { - pr->hostname[1] = 0; /* succeeded */ - sk_write(pr->s, pr->hostname, alen + 6); + /* REP=0 (success) already */ + sk_write(pr->s, (char *) reply, lenof(reply)); memmove(pr->hostname, pr->hostname + 5, alen-1); pr->hostname[alen-1] = '\0'; goto connect; @@ -261,14 +259,14 @@ static int pfd_receive(Plug plug, int urgent, char *data, int len) /* * Unknown address type. (FIXME: support IPv6!) */ - pr->hostname[1] = 8; /* atype not supported */ - sk_write(pr->s, pr->hostname, pr->port); + reply[1] = 8; /* atype not supported */ + sk_write(pr->s, (char *) reply, lenof(reply)); pfd_close(pr->s); - return 1; + return 1; } } } - + /* * If we get here without either having done `continue' * or `goto connect', it must be because there is no @@ -286,6 +284,12 @@ static int pfd_receive(Plug plug, int urgent, char *data, int len) */ connect: + /* + * Freeze the socket until the SSH server confirms the + * connection. + */ + sk_set_frozen(pr->s, 1); + pr->c = new_sock_channel(pr->backhandle, pr->s); if (pr->c == NULL) { pfd_close(pr->s); @@ -297,11 +301,6 @@ static int pfd_receive(Plug plug, int urgent, char *data, int len) pr->dynamic = 0; /* - * Now freeze the socket until the SSH server confirms the - * connection. - */ - sk_set_frozen(pr->s, 1); - /* * If there's any data remaining in our current buffer, * save it to be sent on pfd_confirm(). */ @@ -331,10 +330,11 @@ static void pfd_sent(Plug plug, int bufsize) /* * Called when receiving a PORT OPEN from the server */ -char *pfd_newconnect(Socket *s, char *hostname, int port, void *c, - const Config *cfg) +const char *pfd_newconnect(Socket *s, char *hostname, int port, + void *c, Conf *conf, int addressfamily) { static const struct plug_function_table fn_table = { + pfd_log, pfd_closing, pfd_receive, pfd_sent, @@ -342,15 +342,18 @@ char *pfd_newconnect(Socket *s, char *hostname, int port, void *c, }; SockAddr addr; - char *err, *dummy_realhost; + const char *err; + char *dummy_realhost; struct PFwdPrivate *pr; /* * Try to find host. */ - addr = name_lookup(hostname, port, &dummy_realhost, cfg); - if ((err = sk_addr_error(addr)) != NULL) + addr = name_lookup(hostname, port, &dummy_realhost, conf, addressfamily); + if ((err = sk_addr_error(addr)) != NULL) { + sk_addr_free(addr); return err; + } /* * Open socket. @@ -365,14 +368,13 @@ char *pfd_newconnect(Socket *s, char *hostname, int port, void *c, pr->dynamic = 0; pr->s = *s = new_connection(addr, dummy_realhost, port, - 0, 1, 0, (Plug) pr, cfg); + 0, 1, 0, 0, (Plug) pr, conf); if ((err = sk_socket_error(*s)) != NULL) { sfree(pr); return err; } sk_set_private_ptr(*s, pr); - sk_addr_free(addr); return NULL; } @@ -380,9 +382,10 @@ char *pfd_newconnect(Socket *s, char *hostname, int port, void *c, called when someone connects to the local port */ -static int pfd_accepting(Plug p, void *sock) +static int pfd_accepting(Plug p, OSSocket sock) { static const struct plug_function_table fn_table = { + pfd_log, pfd_closing, pfd_receive, pfd_sent, @@ -390,7 +393,7 @@ static int pfd_accepting(Plug p, void *sock) }; struct PFwdPrivate *pr, *org; Socket s; - char *err; + const char *err; org = (struct PFwdPrivate *)p; pr = snew(struct PFwdPrivate); @@ -413,7 +416,7 @@ static int pfd_accepting(Plug p, void *sock) if (org->dynamic) { pr->dynamic = 1; - pr->port = 0; /* hostname buffer is so far empty */ + pr->port = 0; /* "hostname" buffer is so far empty */ sk_set_frozen(s, 0); /* we want to receive SOCKS _now_! */ } else { pr->dynamic = 0; @@ -437,17 +440,19 @@ static int pfd_accepting(Plug p, void *sock) /* Add a new forwarding from port -> desthost:destport sets up a listener on the local machine on (srcaddr:)port */ -char *pfd_addforward(char *desthost, int destport, char *srcaddr, int port, - void *backhandle, const Config *cfg) +const char *pfd_addforward(char *desthost, int destport, char *srcaddr, + int port, void *backhandle, Conf *conf, + void **sockdata, int address_family) { static const struct plug_function_table fn_table = { + pfd_log, pfd_closing, pfd_receive, /* should not happen... */ pfd_sent, /* also should not happen */ pfd_accepting }; - char *err; + const char *err; struct PFwdPrivate *pr; Socket s; @@ -469,7 +474,8 @@ char *pfd_addforward(char *desthost, int destport, char *srcaddr, int port, pr->backhandle = backhandle; pr->s = s = new_listener(srcaddr, port, (Plug) pr, - !cfg->lport_acceptall, cfg); + !conf_get_int(conf, CONF_lport_acceptall), + conf, address_family); if ((err = sk_socket_error(s)) != NULL) { sfree(pr); return err; @@ -477,6 +483,8 @@ char *pfd_addforward(char *desthost, int destport, char *srcaddr, int port, sk_set_private_ptr(s, pr); + *sockdata = (void *)s; + return NULL; } @@ -495,6 +503,14 @@ void pfd_close(Socket s) sk_close(s); } +/* + * Terminate a listener. + */ +void pfd_terminate(void *sv) +{ + pfd_close((Socket)sv); +} + void pfd_unthrottle(Socket s) { struct PFwdPrivate *pr; @@ -527,6 +543,10 @@ int pfd_send(Socket s, char *data, int len) return sk_write(s, data, len); } +void pfd_send_eof(Socket s) +{ + sk_write_eof(s); +} void pfd_confirm(Socket s) {