mirror of
https://git.tartarus.org/simon/putty.git
synced 2025-07-06 14:02:47 -05:00
Created a shiny new abstraction for the socket handling. Has many
advantages: - protocol modules can call sk_write() without having to worry about writes blocking, because blocking writes are handled in the abstraction layer and retried later. - `Lost connection while sending' is a thing of the past. - <winsock.h> is no longer needed in most modules, because "putty.h" doesn't have to declare `SOCKET' variables any more, only the abstracted `Socket' type. - select()-equivalent between multiple sockets will now be handled sensibly, which opens the way for things like SSH port forwarding. [originally from svn r744]
This commit is contained in:
Simon Tatham
415
ssh.c
415
ssh.c
@ -1,14 +1,8 @@
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#include <windows.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <stdarg.h>
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#include <assert.h>
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#ifndef AUTO_WINSOCK
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#ifdef WINSOCK_TWO
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#include <winsock2.h>
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#else
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#include <winsock.h>
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#endif
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#endif
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#include "putty.h"
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#include "tree234.h"
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@ -25,8 +19,8 @@
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if ((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)) \
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fprintf(stderr, "%s\n", s); }
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#define bombout(msg) ( ssh_state = SSH_STATE_CLOSED, closesocket(s), \
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s = INVALID_SOCKET, connection_fatal msg )
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#define bombout(msg) ( ssh_state = SSH_STATE_CLOSED, sk_close(s), \
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s = NULL, connection_fatal msg )
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#define SSH1_MSG_DISCONNECT 1 /* 0x1 */
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#define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */
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@ -217,7 +211,7 @@ struct Packet {
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static SHA_State exhash;
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static SOCKET s = INVALID_SOCKET;
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static Socket s = NULL;
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static unsigned char session_key[32];
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static const struct ssh_cipher *cipher = NULL;
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@ -288,32 +282,6 @@ static int ssh_channelfind(void *av, void *bv) {
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return 0;
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}
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static void s_write (char *buf, int len) {
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while (len > 0) {
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int i = send (s, buf, len, 0);
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noise_ultralight(i);
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if (i <= 0) {
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bombout(("Lost connection while sending"));
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return;
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}
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if (i > 0)
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len -= i, buf += i;
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}
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}
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static int s_read (char *buf, int len) {
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int ret = 0;
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while (len > 0) {
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int i = recv (s, buf, len, 0);
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noise_ultralight(i);
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if (i > 0)
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len -= i, buf += i, ret += i;
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else
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return i;
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}
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return ret;
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}
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static void c_write (char *buf, int len) {
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if ((flags & FLAG_STDERR)) {
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int i;
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@ -544,19 +512,6 @@ next_packet:
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crFinish(0);
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}
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static void ssh_gotdata(unsigned char *data, int datalen)
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{
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while (datalen > 0) {
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if ( s_rdpkt(&data, &datalen) == 0 ) {
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ssh_protocol(NULL, 0, 1);
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if (ssh_state == SSH_STATE_CLOSED) {
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return;
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}
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}
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}
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}
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static void s_wrpkt_start(int type, int len) {
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int pad, biglen;
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@ -608,7 +563,7 @@ static void s_wrpkt(void) {
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if (cipher)
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cipher->encrypt(pktout.data+4, biglen);
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s_write(pktout.data, biglen+4);
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sk_write(s, pktout.data, biglen+4);
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}
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/*
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@ -695,109 +650,6 @@ static void send_packet(int pkttype, ...)
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s_wrpkt();
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}
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/*
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* Connect to specified host and port.
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* Returns an error message, or NULL on success.
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* Also places the canonical host name into `realhost'.
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*/
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static char *connect_to_host(char *host, int port, char **realhost)
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{
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SOCKADDR_IN addr;
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struct hostent *h;
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unsigned long a;
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#ifdef FWHACK
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char *FWhost;
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int FWport;
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#endif
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savedhost = malloc(1+strlen(host));
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if (!savedhost)
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fatalbox("Out of memory");
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strcpy(savedhost, host);
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if (port < 0)
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port = 22; /* default ssh port */
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savedport = port;
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#ifdef FWHACK
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FWhost = host;
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FWport = port;
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host = FWSTR;
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port = 23;
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#endif
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/*
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* Try to find host.
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*/
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if ( (a = inet_addr(host)) == (unsigned long) INADDR_NONE) {
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if ( (h = gethostbyname(host)) == NULL)
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switch (WSAGetLastError()) {
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case WSAENETDOWN: return "Network is down";
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case WSAHOST_NOT_FOUND: case WSANO_DATA:
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return "Host does not exist";
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case WSATRY_AGAIN: return "Host not found";
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default: return "gethostbyname: unknown error";
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}
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memcpy (&a, h->h_addr, sizeof(a));
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*realhost = h->h_name;
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} else
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*realhost = host;
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#ifdef FWHACK
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*realhost = FWhost;
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#endif
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a = ntohl(a);
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/*
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* Open socket.
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*/
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s = socket(AF_INET, SOCK_STREAM, 0);
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if (s == INVALID_SOCKET)
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switch (WSAGetLastError()) {
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case WSAENETDOWN: return "Network is down";
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case WSAEAFNOSUPPORT: return "TCP/IP support not present";
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default: return "socket(): unknown error";
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}
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/*
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* Bind to local address.
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*/
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addr.sin_family = AF_INET;
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addr.sin_addr.s_addr = htonl(INADDR_ANY);
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addr.sin_port = htons(0);
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if (bind (s, (struct sockaddr *)&addr, sizeof(addr)) == SOCKET_ERROR)
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switch (WSAGetLastError()) {
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case WSAENETDOWN: return "Network is down";
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default: return "bind(): unknown error";
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}
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/*
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* Connect to remote address.
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*/
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addr.sin_addr.s_addr = htonl(a);
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addr.sin_port = htons((short)port);
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if (connect (s, (struct sockaddr *)&addr, sizeof(addr)) == SOCKET_ERROR)
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switch (WSAGetLastError()) {
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case WSAENETDOWN: return "Network is down";
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case WSAECONNREFUSED: return "Connection refused";
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case WSAENETUNREACH: return "Network is unreachable";
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case WSAEHOSTUNREACH: return "No route to host";
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default: return "connect(): unknown error";
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}
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#ifdef FWHACK
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send(s, "connect ", 8, 0);
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send(s, FWhost, strlen(FWhost), 0);
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{
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char buf[20];
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sprintf(buf, " %d\n", FWport);
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send (s, buf, strlen(buf), 0);
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}
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#endif
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return NULL;
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}
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static int ssh_versioncmp(char *a, char *b) {
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char *ae, *be;
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unsigned long av, bv;
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@ -931,7 +783,7 @@ static void ssh2_pkt_send(void) {
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cscipher->encrypt(pktout.data, pktout.length + padding);
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maclen = csmac ? csmac->len : 0;
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s_write(pktout.data, pktout.length + padding + maclen);
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sk_write(s, pktout.data, pktout.length + padding + maclen);
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}
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#if 0
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@ -1000,33 +852,35 @@ static Bignum ssh2_pkt_getmp(void) {
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return b;
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}
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static int do_ssh_init(void) {
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char c, *vsp;
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char version[10];
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char vstring[80];
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char vlog[sizeof(vstring)+20];
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int i;
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static int do_ssh_init(unsigned char c) {
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static char *vsp;
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static char version[10];
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static char vstring[80];
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static char vlog[sizeof(vstring)+20];
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static int i;
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#ifdef FWHACK
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i = 0;
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while (s_read(&c, 1) == 1) {
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if (c == 'S' && i < 2) i++;
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else if (c == 'S' && i == 2) i = 2;
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else if (c == 'H' && i == 2) break;
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else i = 0;
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}
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#else
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if (s_read(&c,1) != 1 || c != 'S') return 0;
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if (s_read(&c,1) != 1 || c != 'S') return 0;
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if (s_read(&c,1) != 1 || c != 'H') return 0;
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#endif
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strcpy(vstring, "SSH-");
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vsp = vstring+4;
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if (s_read(&c,1) != 1 || c != '-') return 0;
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crBegin;
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/* Search for the string "SSH-" in the input. */
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i = 0;
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while (1) {
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if (s_read(&c,1) != 1)
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return 0;
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static const int transS[] = { 1, 2, 2, 1 };
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static const int transH[] = { 0, 0, 3, 0 };
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static const int transminus[] = { 0, 0, 0, -1 };
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if (c == 'S') i = transS[i];
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else if (c == 'H') i = transH[i];
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else if (c == '-') i = transminus[i];
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else i = 0;
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if (i < 0)
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break;
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crReturn(1); /* get another character */
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}
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strcpy(vstring, "SSH-");
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vsp = vstring+4;
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i = 0;
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while (1) {
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crReturn(1); /* get another char */
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if (vsp < vstring+sizeof(vstring)-1)
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*vsp++ = c;
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if (i >= 0) {
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@ -1066,7 +920,7 @@ static int do_ssh_init(void) {
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sprintf(vlog, "We claim version: %s", verstring);
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logevent(vlog);
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logevent("Using SSH protocol version 2");
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s_write(vstring, strlen(vstring));
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sk_write(s, vstring, strlen(vstring));
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ssh_protocol = ssh2_protocol;
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ssh_version = 2;
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s_rdpkt = ssh2_rdpkt;
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@ -1080,15 +934,129 @@ static int do_ssh_init(void) {
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vlog[strcspn(vlog, "\r\n")] = '\0';
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logevent(vlog);
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logevent("Using SSH protocol version 1");
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s_write(vstring, strlen(vstring));
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sk_write(s, vstring, strlen(vstring));
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ssh_protocol = ssh1_protocol;
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ssh_version = 1;
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s_rdpkt = ssh1_rdpkt;
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}
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ssh_send_ok = 0;
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crFinish(0);
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}
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static void ssh_gotdata(unsigned char *data, int datalen)
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{
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crBegin;
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/*
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* To begin with, feed the characters one by one to the
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* protocol initialisation / selection function do_ssh_init().
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* When that returns 0, we're done with the initial greeting
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* exchange and can move on to packet discipline.
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*/
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while (1) {
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int ret;
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if (datalen == 0)
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crReturnV; /* more data please */
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ret = do_ssh_init(*data);
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data++; datalen--;
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if (ret == 0)
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break;
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}
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/*
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* We emerge from that loop when the initial negotiation is
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* over and we have selected an s_rdpkt function. Now pass
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* everything to s_rdpkt, and then pass the resulting packets
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* to the proper protocol handler.
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*/
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if (datalen == 0)
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crReturnV;
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while (1) {
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while (datalen > 0) {
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if ( s_rdpkt(&data, &datalen) == 0 ) {
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ssh_protocol(NULL, 0, 1);
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if (ssh_state == SSH_STATE_CLOSED) {
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return;
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}
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}
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}
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crReturnV;
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}
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crFinishV;
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}
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static int ssh_receive(Socket s, int urgent, char *data, int len) {
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if (!len) {
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/* Connection has closed. */
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sk_close(s);
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s = NULL;
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return 0;
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}
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ssh_gotdata (data, len);
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return 1;
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}
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/*
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* Connect to specified host and port.
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* Returns an error message, or NULL on success.
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* Also places the canonical host name into `realhost'.
|
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*/
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static char *connect_to_host(char *host, int port, char **realhost)
|
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{
|
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SockAddr addr;
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char *err;
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#ifdef FWHACK
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char *FWhost;
|
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int FWport;
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#endif
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savedhost = malloc(1+strlen(host));
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if (!savedhost)
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fatalbox("Out of memory");
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strcpy(savedhost, host);
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if (port < 0)
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port = 22; /* default ssh port */
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savedport = port;
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#ifdef FWHACK
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FWhost = host;
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FWport = port;
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host = FWSTR;
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port = 23;
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#endif
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/*
|
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* Try to find host.
|
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*/
|
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addr = sk_namelookup(host, realhost);
|
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if ( (err = sk_addr_error(addr)) )
|
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return err;
|
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|
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#ifdef FWHACK
|
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*realhost = FWhost;
|
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#endif
|
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|
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/*
|
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* Open socket.
|
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*/
|
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s = sk_new(addr, port, ssh_receive);
|
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if ( (err = sk_socket_error(s)) )
|
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return err;
|
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|
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#ifdef FWHACK
|
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sk_write(s, "connect ", 8);
|
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sk_write(s, FWhost, strlen(FWhost));
|
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{
|
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char buf[20];
|
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sprintf(buf, " %d\n", FWport);
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sk_write(s, buf, strlen(buf));
|
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}
|
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#endif
|
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|
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return NULL;
|
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}
|
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|
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/*
|
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* Handle the key exchange and user authentication phases.
|
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*/
|
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@ -1775,8 +1743,13 @@ static void ssh1_protocol(unsigned char *in, int inlen, int ispkt) {
|
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crReturnV;
|
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}
|
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} else {
|
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send_packet(SSH1_CMSG_STDIN_DATA,
|
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PKT_INT, inlen, PKT_DATA, in, inlen, PKT_END);
|
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while (inlen > 0) {
|
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int len = min(inlen, 512);
|
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send_packet(SSH1_CMSG_STDIN_DATA,
|
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PKT_INT, len, PKT_DATA, in, len, PKT_END);
|
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in += len;
|
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inlen -= len;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
@ -2441,8 +2414,8 @@ static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
|
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ssh2_pkt_init(SSH2_MSG_DISCONNECT);
|
||||
ssh2_pkt_send();
|
||||
ssh_state = SSH_STATE_CLOSED;
|
||||
closesocket(s);
|
||||
s = INVALID_SOCKET;
|
||||
sk_close(s);
|
||||
s = NULL;
|
||||
}
|
||||
continue; /* remote sends close; ignore (FIXME) */
|
||||
} else if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
|
||||
@ -2510,13 +2483,11 @@ static void ssh2_protocol(unsigned char *in, int inlen, int ispkt)
|
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}
|
||||
|
||||
/*
|
||||
* Called to set up the connection. Will arrange for WM_NETEVENT
|
||||
* messages to be passed to the specified window, whose window
|
||||
* procedure should then call telnet_msg().
|
||||
* Called to set up the connection.
|
||||
*
|
||||
* Returns an error message, or NULL on success.
|
||||
*/
|
||||
static char *ssh_init (HWND hwnd, char *host, int port, char **realhost) {
|
||||
static char *ssh_init (char *host, int port, char **realhost) {
|
||||
char *p;
|
||||
|
||||
#ifdef MSCRYPTOAPI
|
||||
@ -2524,77 +2495,20 @@ static char *ssh_init (HWND hwnd, char *host, int port, char **realhost) {
|
||||
return "Microsoft high encryption pack not installed!";
|
||||
#endif
|
||||
|
||||
ssh_send_ok = 0;
|
||||
|
||||
p = connect_to_host(host, port, realhost);
|
||||
if (p != NULL)
|
||||
return p;
|
||||
|
||||
if (!do_ssh_init())
|
||||
return "Protocol initialisation error";
|
||||
|
||||
if (hwnd && WSAAsyncSelect (s, hwnd, WM_NETEVENT, FD_READ | FD_CLOSE) == SOCKET_ERROR)
|
||||
switch (WSAGetLastError()) {
|
||||
case WSAENETDOWN: return "Network is down";
|
||||
default: return "WSAAsyncSelect(): unknown error";
|
||||
}
|
||||
|
||||
return NULL;
|
||||
}
|
||||
|
||||
/*
|
||||
* Process a WM_NETEVENT message. Will return 0 if the connection
|
||||
* has closed, or <0 for a socket error.
|
||||
*/
|
||||
static int ssh_msg (WPARAM wParam, LPARAM lParam) {
|
||||
int ret;
|
||||
char buf[256];
|
||||
|
||||
/*
|
||||
* Because reading less than the whole of the available pending
|
||||
* data can generate an FD_READ event, we need to allow for the
|
||||
* possibility that FD_READ may arrive with FD_CLOSE already in
|
||||
* the queue; so it's possible that we can get here even with s
|
||||
* invalid. If so, we return 1 and don't worry about it.
|
||||
*/
|
||||
if (s == INVALID_SOCKET)
|
||||
return 1;
|
||||
|
||||
if (WSAGETSELECTERROR(lParam) != 0) {
|
||||
closesocket(s);
|
||||
s = INVALID_SOCKET;
|
||||
return -WSAGETSELECTERROR(lParam);
|
||||
}
|
||||
|
||||
switch (WSAGETSELECTEVENT(lParam)) {
|
||||
case FD_READ:
|
||||
case FD_CLOSE:
|
||||
ret = recv(s, buf, sizeof(buf), 0);
|
||||
if (ret < 0 && WSAGetLastError() == WSAEWOULDBLOCK)
|
||||
return 1;
|
||||
if (ret < 0) { /* any _other_ error */
|
||||
closesocket(s);
|
||||
s = INVALID_SOCKET;
|
||||
return -10000-WSAGetLastError();
|
||||
}
|
||||
if (ret == 0) {
|
||||
s = INVALID_SOCKET;
|
||||
return 0;
|
||||
}
|
||||
ssh_gotdata (buf, ret);
|
||||
if (ssh_state == SSH_STATE_CLOSED) {
|
||||
closesocket(s);
|
||||
s = INVALID_SOCKET;
|
||||
return 0;
|
||||
}
|
||||
return 1;
|
||||
}
|
||||
return 1; /* shouldn't happen, but WTF */
|
||||
}
|
||||
|
||||
/*
|
||||
* Called to send data down the Telnet connection.
|
||||
*/
|
||||
static void ssh_send (char *buf, int len) {
|
||||
if (s == INVALID_SOCKET)
|
||||
if (s == NULL)
|
||||
return;
|
||||
|
||||
ssh_protocol(buf, len, 0);
|
||||
@ -2648,13 +2562,12 @@ static void ssh_special (Telnet_Special code) {
|
||||
}
|
||||
}
|
||||
|
||||
static SOCKET ssh_socket(void) { return s; }
|
||||
static Socket ssh_socket(void) { return s; }
|
||||
|
||||
static int ssh_sendok(void) { return ssh_send_ok; }
|
||||
|
||||
Backend ssh_backend = {
|
||||
ssh_init,
|
||||
ssh_msg,
|
||||
ssh_send,
|
||||
ssh_size,
|
||||
ssh_special,
|
||||
|
||||
Reference in New Issue
Block a user