extern char *x11_init(Socket *, char *, void *);
extern void x11_close(Socket);
-extern void x11_send(Socket, char *, int);
+extern int x11_send(Socket, char *, int);
extern void x11_invent_auth(char *, int, char *, int);
+extern void x11_unthrottle(Socket s);
+extern void x11_override_throttle(Socket s, int enable);
extern char *pfd_newconnect(Socket * s, char *hostname, int port, void *c);
extern char *pfd_addforward(char *desthost, int destport, int port);
extern void pfd_close(Socket s);
-extern void pfd_send(Socket s, char *data, int len);
+extern int pfd_send(Socket s, char *data, int len);
extern void pfd_confirm(Socket s);
+extern void pfd_unthrottle(Socket s);
+extern void pfd_override_throttle(Socket s, int enable);
+
+/*
+ * Buffer management constants. There are several of these for
+ * various different purposes:
+ *
+ * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
+ * on a local data stream before we throttle the whole SSH
+ * connection (in SSH1 only). Throttling the whole connection is
+ * pretty drastic so we set this high in the hope it won't
+ * happen very often.
+ *
+ * - SSH_MAX_BACKLOG is the amount of backlog that must build up
+ * on the SSH connection itself before we defensively throttle
+ * _all_ local data streams. This is pretty drastic too (though
+ * thankfully unlikely in SSH2 since the window mechanism should
+ * ensure that the server never has any need to throttle its end
+ * of the connection), so we set this high as well.
+ *
+ * - OUR_V2_WINSIZE is the maximum window size we present on SSH2
+ * channels.
+ */
+
+#define SSH1_BUFFER_LIMIT 32768
+#define SSH_MAX_BACKLOG 32768
+#define OUR_V2_WINSIZE 16384
/*
* Ciphers for SSH2. We miss out single-DES because it isn't
unsigned remoteid, localid;
int type;
int closes;
- struct ssh2_data_channel {
- unsigned char *outbuffer;
- unsigned outbuflen, outbufsize;
- unsigned remwindow, remmaxpkt;
- } v2;
+ union {
+ struct ssh1_data_channel {
+ int throttling;
+ } v1;
+ struct ssh2_data_channel {
+ bufchain outbuffer;
+ unsigned remwindow, remmaxpkt;
+ unsigned locwindow;
+ } v2;
+ } v;
union {
struct ssh_agent_channel {
unsigned char *message;
static unsigned char *deferred_send_data = NULL;
static int deferred_len = 0, deferred_size = 0;
+/*
+ * Gross hack: pscp will try to start SFTP but fall back to scp1 if
+ * that fails. This variable is the means by which scp.c can reach
+ * into the SSH code and find out which one it got.
+ */
+int ssh_fallback_cmd = 0;
+
static int ssh_version;
+static int ssh1_throttle_count;
+static int ssh_overall_bufsize;
+static int ssh_throttled_all;
+static int ssh1_stdout_throttling;
static void (*ssh_protocol) (unsigned char *in, int inlen, int ispkt);
static void ssh1_protocol(unsigned char *in, int inlen, int ispkt);
static void ssh2_protocol(unsigned char *in, int inlen, int ispkt);
static void ssh_size(void);
static void ssh_special(Telnet_Special);
-static void ssh2_try_send(struct ssh_channel *c);
+static int ssh2_try_send(struct ssh_channel *c);
static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
int len);
-
+static void ssh_throttle_all(int enable, int bufsize);
+static void ssh2_set_window(struct ssh_channel *c, unsigned newwin);
static int (*s_rdpkt) (unsigned char **data, int *datalen);
+static int ssh_sendbuffer(void);
static struct rdpkt1_state_tag {
long len, pad, biglen, to_read;
static void s_wrpkt(void)
{
- int len;
+ int len, backlog;
len = s_wrpkt_prepare();
- sk_write(s, pktout.data, len);
+ backlog = sk_write(s, pktout.data, len);
+ if (backlog > SSH_MAX_BACKLOG)
+ ssh_throttle_all(1, backlog);
}
static void s_wrpkt_defer(void)
*/
static void ssh2_pkt_send(void)
{
- int len = ssh2_pkt_construct();
- sk_write(s, pktout.data, len);
+ int len;
+ int backlog;
+ len = ssh2_pkt_construct();
+ backlog = sk_write(s, pktout.data, len);
+ if (backlog > SSH_MAX_BACKLOG)
+ ssh_throttle_all(1, backlog);
}
/*
*/
static void ssh_pkt_defersend(void)
{
- sk_write(s, deferred_send_data, deferred_len);
+ int backlog;
+ backlog = sk_write(s, deferred_send_data, deferred_len);
deferred_len = deferred_size = 0;
sfree(deferred_send_data);
deferred_send_data = NULL;
+ if (backlog > SSH_MAX_BACKLOG)
+ ssh_throttle_all(1, backlog);
}
#if 0
return 1;
}
+static void ssh_sent(Plug plug, int bufsize)
+{
+ /*
+ * If the send backlog on the SSH socket itself clears, we
+ * should unthrottle the whole world if it was throttled.
+ */
+ if (bufsize < SSH_MAX_BACKLOG)
+ ssh_throttle_all(0, bufsize);
+}
+
/*
* Connect to specified host and port.
* Returns an error message, or NULL on success.
{
static struct plug_function_table fn_table = {
ssh_closing,
- ssh_receive
+ ssh_receive,
+ ssh_sent,
+ NULL
}, *fn_table_ptr = &fn_table;
SockAddr addr;
}
/*
+ * Throttle or unthrottle the SSH connection.
+ */
+static void ssh1_throttle(int adjust)
+{
+ int old_count = ssh1_throttle_count;
+ ssh1_throttle_count += adjust;
+ assert(ssh1_throttle_count >= 0);
+ if (ssh1_throttle_count && !old_count) {
+ sk_set_frozen(s, 1);
+ } else if (!ssh1_throttle_count && old_count) {
+ sk_set_frozen(s, 0);
+ }
+}
+
+/*
+ * Throttle or unthrottle _all_ local data streams (for when sends
+ * on the SSH connection itself back up).
+ */
+static void ssh_throttle_all(int enable, int bufsize)
+{
+ int i;
+ struct ssh_channel *c;
+
+ if (enable == ssh_throttled_all)
+ return;
+ ssh_throttled_all = enable;
+ ssh_overall_bufsize = bufsize;
+ if (!ssh_channels)
+ return;
+ for (i = 0; NULL != (c = index234(ssh_channels, i)); i++) {
+ switch (c->type) {
+ case CHAN_MAINSESSION:
+ /*
+ * This is treated separately, outside the switch.
+ */
+ break;
+ case CHAN_X11:
+ x11_override_throttle(c->u.x11.s, enable);
+ break;
+ case CHAN_AGENT:
+ /* Agent channels require no buffer management. */
+ break;
+ case CHAN_SOCKDATA:
+ pfd_override_throttle(c->u.x11.s, enable);
+ break;
+ }
+ }
+}
+
+/*
* Handle the key exchange and user authentication phases.
*/
static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
logevent("Encrypted session key");
- switch (cfg.cipher) {
- case CIPHER_BLOWFISH:
- cipher_type = SSH_CIPHER_BLOWFISH;
- break;
- case CIPHER_DES:
- cipher_type = SSH_CIPHER_DES;
- break;
- case CIPHER_3DES:
- cipher_type = SSH_CIPHER_3DES;
- break;
- case CIPHER_AES:
- c_write_str("AES not supported in SSH1, falling back to 3DES\r\n");
- cipher_type = SSH_CIPHER_3DES;
- break;
- }
- if ((supported_ciphers_mask & (1 << cipher_type)) == 0) {
- c_write_str
- ("Selected cipher not supported, falling back to 3DES\r\n");
- cipher_type = SSH_CIPHER_3DES;
- if ((supported_ciphers_mask & (1 << cipher_type)) == 0) {
- bombout(("Server violates SSH 1 protocol by "
- "not supporting 3DES encryption"));
+ {
+ int cipher_chosen = 0, warn = 0;
+ char *cipher_string = NULL;
+ for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
+ int next_cipher = cfg.ssh_cipherlist[i];
+ if (next_cipher == CIPHER_WARN) {
+ /* If/when we choose a cipher, warn about it */
+ warn = 1;
+ } else if (next_cipher == CIPHER_AES) {
+ /* XXX Probably don't need to mention this. */
+ logevent("AES not supported in SSH1, skipping");
+ } else {
+ switch (next_cipher) {
+ case CIPHER_3DES: cipher_type = SSH_CIPHER_3DES;
+ cipher_string = "3DES"; break;
+ case CIPHER_BLOWFISH: cipher_type = SSH_CIPHER_BLOWFISH;
+ cipher_string = "Blowfish"; break;
+ case CIPHER_DES: cipher_type = SSH_CIPHER_DES;
+ cipher_string = "single-DES"; break;
+ }
+ if (supported_ciphers_mask & (1 << cipher_type))
+ cipher_chosen = 1;
+ }
+ }
+ if (!cipher_chosen) {
+ if ((supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
+ bombout(("Server violates SSH 1 protocol by not "
+ "supporting 3DES encryption"));
+ else
+ /* shouldn't happen */
+ bombout(("No supported ciphers found"));
crReturn(0);
}
+
+ /* Warn about chosen cipher if necessary. */
+ if (warn)
+ askcipher(cipher_string, 0);
}
+
switch (cipher_type) {
case SSH_CIPHER_3DES:
logevent("Using 3DES encryption");
}
}
-void sshfwd_write(struct ssh_channel *c, char *buf, int len)
+int sshfwd_write(struct ssh_channel *c, char *buf, int len)
{
if (ssh_version == 1) {
send_packet(SSH1_MSG_CHANNEL_DATA,
PKT_INT, c->remoteid,
PKT_INT, len, PKT_DATA, buf, len, PKT_END);
+ /*
+ * In SSH1 we can return 0 here - implying that forwarded
+ * connections are never individually throttled - because
+ * the only circumstance that can cause throttling will be
+ * the whole SSH connection backing up, in which case
+ * _everything_ will be throttled as a whole.
+ */
+ return 0;
} else {
ssh2_add_channel_data(c, buf, len);
- ssh2_try_send(c);
+ return ssh2_try_send(c);
+ }
+}
+
+void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
+{
+ if (ssh_version == 1) {
+ if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
+ c->v.v1.throttling = 0;
+ ssh1_throttle(-1);
+ }
+ } else {
+ ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
}
}
zlib_decompress_init();
}
- if (*cfg.remote_cmd_ptr)
- send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cfg.remote_cmd_ptr,
- PKT_END);
- else
- send_packet(SSH1_CMSG_EXEC_SHELL, PKT_END);
- logevent("Started session");
+ /*
+ * Start the shell or command.
+ *
+ * Special case: if the first-choice command is an SSH2
+ * subsystem (hence not usable here) and the second choice
+ * exists, we fall straight back to that.
+ */
+ {
+ char *cmd = cfg.remote_cmd_ptr;
+
+ if (cfg.ssh_subsys && cfg.remote_cmd_ptr2) {
+ cmd = cfg.remote_cmd_ptr2;
+ ssh_fallback_cmd = TRUE;
+ }
+ if (*cmd)
+ send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
+ else
+ send_packet(SSH1_CMSG_EXEC_SHELL, PKT_END);
+ logevent("Started session");
+ }
ssh_state = SSH_STATE_SESSION;
if (size_needed)
if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
pktin.type == SSH1_SMSG_STDERR_DATA) {
long len = GET_32BIT(pktin.body);
- from_backend(pktin.type == SSH1_SMSG_STDERR_DATA,
- pktin.body + 4, len);
+ int bufsize =
+ from_backend(pktin.type == SSH1_SMSG_STDERR_DATA,
+ pktin.body + 4, len);
+ if (bufsize > SSH1_BUFFER_LIMIT) {
+ ssh1_stdout_throttling = 1;
+ ssh1_throttle(+1);
+ }
} else if (pktin.type == SSH1_MSG_DISCONNECT) {
ssh_state = SSH_STATE_CLOSED;
logevent("Received disconnect request");
c->remoteid = GET_32BIT(pktin.body);
c->localid = alloc_channel_id();
c->closes = 0;
+ c->v.v1.throttling = 0;
c->type = CHAN_X11; /* identify channel type */
add234(ssh_channels, c);
send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
c->remoteid = GET_32BIT(pktin.body);
c->localid = alloc_channel_id();
c->closes = 0;
+ c->v.v1.throttling = 0;
c->type = CHAN_AGENT; /* identify channel type */
c->u.a.lensofar = 0;
add234(ssh_channels, c);
c->remoteid = GET_32BIT(pktin.body);
c->localid = alloc_channel_id();
c->closes = 0;
+ c->v.v1.throttling = 0;
c->type = CHAN_SOCKDATA; /* identify channel type */
add234(ssh_channels, c);
send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
struct ssh_channel *c;
c = find234(ssh_channels, &i, ssh_channelfind);
if (c) {
+ int bufsize;
switch (c->type) {
case CHAN_X11:
- x11_send(c->u.x11.s, p, len);
+ bufsize = x11_send(c->u.x11.s, p, len);
break;
case CHAN_SOCKDATA:
- pfd_send(c->u.pfd.s, p, len);
+ bufsize = pfd_send(c->u.pfd.s, p, len);
break;
case CHAN_AGENT:
/* Data for an agent message. Buffer it. */
c->u.a.lensofar = 0;
}
}
+ bufsize = 0; /* agent channels never back up */
break;
}
+ if (bufsize > SSH1_BUFFER_LIMIT) {
+ c->v.v1.throttling = 1;
+ ssh1_throttle(+1);
+ }
}
} else if (pktin.type == SSH1_SMSG_SUCCESS) {
/* may be from EXEC_SHELL on some servers */
*/
static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt)
{
- static int i, j, len, nbits, pbits;
+ static int i, j, len, nbits, pbits, warn;
static char *str;
static Bignum p, g, e, f, K;
static int kex_init_value, kex_reply_value;
static void *hkey; /* actual host key */
static unsigned char exchange_hash[20];
static unsigned char keyspace[40];
- static const struct ssh2_ciphers *preferred_cipher;
+ static int n_preferred_ciphers;
+ static const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
static const struct ssh_compress *preferred_comp;
static int first_kex;
first_kex = 1;
/*
- * Set up the preferred cipher and compression.
+ * Set up the preferred ciphers. (NULL => warn below here)
*/
- if (cfg.cipher == CIPHER_BLOWFISH) {
- preferred_cipher = &ssh2_blowfish;
- } else if (cfg.cipher == CIPHER_DES) {
- logevent("Single DES not supported in SSH2; using 3DES");
- preferred_cipher = &ssh2_3des;
- } else if (cfg.cipher == CIPHER_3DES) {
- preferred_cipher = &ssh2_3des;
- } else if (cfg.cipher == CIPHER_AES) {
- preferred_cipher = &ssh2_aes;
- } else {
- /* Shouldn't happen, but we do want to initialise to _something_. */
- preferred_cipher = &ssh2_3des;
+ n_preferred_ciphers = 0;
+ for (i = 0; i < CIPHER_MAX; i++) {
+ switch (cfg.ssh_cipherlist[i]) {
+ case CIPHER_BLOWFISH:
+ preferred_ciphers[n_preferred_ciphers] = &ssh2_blowfish;
+ n_preferred_ciphers++;
+ break;
+ case CIPHER_DES:
+ /* Not supported in SSH2; silently drop */
+ break;
+ case CIPHER_3DES:
+ preferred_ciphers[n_preferred_ciphers] = &ssh2_3des;
+ n_preferred_ciphers++;
+ break;
+ case CIPHER_AES:
+ preferred_ciphers[n_preferred_ciphers] = &ssh2_aes;
+ n_preferred_ciphers++;
+ break;
+ case CIPHER_WARN:
+ /* Flag for later. Don't bother if it's the last in
+ * the list. */
+ if (i < CIPHER_MAX - 1) {
+ preferred_ciphers[n_preferred_ciphers] = NULL;
+ n_preferred_ciphers++;
+ }
+ break;
+ }
}
+
+ /*
+ * Set up preferred compression.
+ */
if (cfg.compression)
preferred_comp = &ssh_zlib;
else
}
/* List client->server encryption algorithms. */
ssh2_pkt_addstring_start();
- for (i = 0; i < lenof(ciphers) + 1; i++) {
- const struct ssh2_ciphers *c =
- i == 0 ? preferred_cipher : ciphers[i - 1];
+ for (i = 0; i < n_preferred_ciphers; i++) {
+ const struct ssh2_ciphers *c = preferred_ciphers[i];
+ if (!c) continue; /* warning flag */
for (j = 0; j < c->nciphers; j++) {
ssh2_pkt_addstring_str(c->list[j]->name);
- if (i < lenof(ciphers) || j < c->nciphers - 1)
+ if (i < n_preferred_ciphers || j < c->nciphers - 1)
ssh2_pkt_addstring_str(",");
}
}
/* List server->client encryption algorithms. */
ssh2_pkt_addstring_start();
- for (i = 0; i < lenof(ciphers) + 1; i++) {
- const struct ssh2_ciphers *c =
- i == 0 ? preferred_cipher : ciphers[i - 1];
+ for (i = 0; i < n_preferred_ciphers; i++) {
+ const struct ssh2_ciphers *c = preferred_ciphers[i];
+ if (!c) continue; /* warning flag */
for (j = 0; j < c->nciphers; j++) {
ssh2_pkt_addstring_str(c->list[j]->name);
- if (i < lenof(ciphers) || j < c->nciphers - 1)
+ if (i < n_preferred_ciphers || j < c->nciphers - 1)
ssh2_pkt_addstring_str(",");
}
}
}
}
ssh2_pkt_getstring(&str, &len); /* client->server cipher */
- for (i = 0; i < lenof(ciphers) + 1; i++) {
- const struct ssh2_ciphers *c =
- i == 0 ? preferred_cipher : ciphers[i - 1];
- for (j = 0; j < c->nciphers; j++) {
- if (in_commasep_string(c->list[j]->name, str, len)) {
- cscipher_tobe = c->list[j];
- break;
+ warn = 0;
+ for (i = 0; i < n_preferred_ciphers; i++) {
+ const struct ssh2_ciphers *c = preferred_ciphers[i];
+ if (!c) {
+ warn = 1;
+ } else {
+ for (j = 0; j < c->nciphers; j++) {
+ if (in_commasep_string(c->list[j]->name, str, len)) {
+ cscipher_tobe = c->list[j];
+ break;
+ }
}
}
- if (cscipher_tobe)
+ if (cscipher_tobe) {
+ if (warn)
+ askcipher(cscipher_tobe->name, 1);
break;
+ }
}
ssh2_pkt_getstring(&str, &len); /* server->client cipher */
- for (i = 0; i < lenof(ciphers) + 1; i++) {
- const struct ssh2_ciphers *c =
- i == 0 ? preferred_cipher : ciphers[i - 1];
- for (j = 0; j < c->nciphers; j++) {
- if (in_commasep_string(c->list[j]->name, str, len)) {
- sccipher_tobe = c->list[j];
- break;
+ warn = 0;
+ for (i = 0; i < n_preferred_ciphers; i++) {
+ const struct ssh2_ciphers *c = preferred_ciphers[i];
+ if (!c) {
+ warn = 1;
+ } else {
+ for (j = 0; j < c->nciphers; j++) {
+ if (in_commasep_string(c->list[j]->name, str, len)) {
+ sccipher_tobe = c->list[j];
+ break;
+ }
}
}
- if (sccipher_tobe)
+ if (sccipher_tobe) {
+ if (warn)
+ askcipher(sccipher_tobe->name, 2);
break;
+ }
}
ssh2_pkt_getstring(&str, &len); /* client->server mac */
for (i = 0; i < nmacs; i++) {
static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
int len)
{
- if (c->v2.outbufsize < c->v2.outbuflen + len) {
- c->v2.outbufsize = c->v2.outbuflen + len + 1024;
- c->v2.outbuffer = srealloc(c->v2.outbuffer, c->v2.outbufsize);
- }
- memcpy(c->v2.outbuffer + c->v2.outbuflen, buf, len);
- c->v2.outbuflen += len;
+ bufchain_add(&c->v.v2.outbuffer, buf, len);
}
/*
* Attempt to send data on an SSH2 channel.
*/
-static void ssh2_try_send(struct ssh_channel *c)
+static int ssh2_try_send(struct ssh_channel *c)
{
- while (c->v2.remwindow > 0 && c->v2.outbuflen > 0) {
- unsigned len = c->v2.remwindow;
- if (len > c->v2.outbuflen)
- len = c->v2.outbuflen;
- if (len > c->v2.remmaxpkt)
- len = c->v2.remmaxpkt;
+ while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
+ int len;
+ void *data;
+ bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
+ if ((unsigned)len > c->v.v2.remwindow)
+ len = c->v.v2.remwindow;
+ if ((unsigned)len > c->v.v2.remmaxpkt)
+ len = c->v.v2.remmaxpkt;
ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
ssh2_pkt_adduint32(c->remoteid);
ssh2_pkt_addstring_start();
- ssh2_pkt_addstring_data(c->v2.outbuffer, len);
+ ssh2_pkt_addstring_data(data, len);
+ ssh2_pkt_send();
+ bufchain_consume(&c->v.v2.outbuffer, len);
+ c->v.v2.remwindow -= len;
+ }
+
+ /*
+ * After having sent as much data as we can, return the amount
+ * still buffered.
+ */
+ return bufchain_size(&c->v.v2.outbuffer);
+}
+
+/*
+ * Potentially enlarge the window on an SSH2 channel.
+ */
+static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
+{
+ if (newwin > c->v.v2.locwindow) {
+ ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
+ ssh2_pkt_adduint32(c->remoteid);
+ ssh2_pkt_adduint32(newwin - c->v.v2.locwindow);
ssh2_pkt_send();
- c->v2.outbuflen -= len;
- memmove(c->v2.outbuffer, c->v2.outbuffer + len, c->v2.outbuflen);
- c->v2.remwindow -= len;
+ c->v.v2.locwindow = newwin;
}
}
* This is a further prompt in keyboard-interactive
* authentication. Do nothing.
*/
- } else if (!pktin.type != SSH2_MSG_USERAUTH_FAILURE) {
+ } else if (pktin.type != SSH2_MSG_USERAUTH_FAILURE) {
bombout(("Strange packet received during authentication: type %d",
pktin.type));
crReturnV;
ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
ssh2_pkt_addstring("session");
ssh2_pkt_adduint32(mainchan->localid);
- ssh2_pkt_adduint32(0x8000UL); /* our window size */
+ mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
+ ssh2_pkt_adduint32(mainchan->v.v2.locwindow); /* our window size */
ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
ssh2_pkt_send();
crWaitUntilV(ispkt);
mainchan->remoteid = ssh2_pkt_getuint32();
mainchan->type = CHAN_MAINSESSION;
mainchan->closes = 0;
- mainchan->v2.remwindow = ssh2_pkt_getuint32();
- mainchan->v2.remmaxpkt = ssh2_pkt_getuint32();
- mainchan->v2.outbuffer = NULL;
- mainchan->v2.outbuflen = mainchan->v2.outbufsize = 0;
+ mainchan->v.v2.remwindow = ssh2_pkt_getuint32();
+ mainchan->v.v2.remmaxpkt = ssh2_pkt_getuint32();
+ bufchain_init(&mainchan->v.v2.outbuffer);
add234(ssh_channels, mainchan);
logevent("Opened channel for session");
c = find234(ssh_channels, &i, ssh_channelfind);
if (!c)
continue; /* nonexistent channel */
- c->v2.remwindow += ssh2_pkt_getuint32();
+ c->v.v2.remwindow += ssh2_pkt_getuint32();
}
} while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
c = find234(ssh_channels, &i, ssh_channelfind);
if (!c)
continue;/* nonexistent channel */
- c->v2.remwindow += ssh2_pkt_getuint32();
+ c->v.v2.remwindow += ssh2_pkt_getuint32();
}
} while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
c = find234(ssh_channels, &i, ssh_channelfind);
if (!c)
continue; /* nonexistent channel */
- c->v2.remwindow += ssh2_pkt_getuint32();
+ c->v.v2.remwindow += ssh2_pkt_getuint32();
}
} while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
c = find234(ssh_channels, &i, ssh_channelfind);
if (!c)
continue; /* nonexistent channel */
- c->v2.remwindow += ssh2_pkt_getuint32();
+ c->v.v2.remwindow += ssh2_pkt_getuint32();
}
} while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
}
/*
- * Start a shell or a remote command.
+ * Start a shell or a remote command. We may have to attempt
+ * this twice if the config data has provided a second choice
+ * of command.
*/
- ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
- ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
- if (cfg.ssh_subsys) {
- ssh2_pkt_addstring("subsystem");
- ssh2_pkt_addbool(1); /* want reply */
- ssh2_pkt_addstring(cfg.remote_cmd_ptr);
- } else if (*cfg.remote_cmd_ptr) {
- ssh2_pkt_addstring("exec");
- ssh2_pkt_addbool(1); /* want reply */
- ssh2_pkt_addstring(cfg.remote_cmd_ptr);
- } else {
- ssh2_pkt_addstring("shell");
- ssh2_pkt_addbool(1); /* want reply */
- }
- ssh2_pkt_send();
- do {
- crWaitUntilV(ispkt);
- if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
- unsigned i = ssh2_pkt_getuint32();
- struct ssh_channel *c;
- c = find234(ssh_channels, &i, ssh_channelfind);
- if (!c)
- continue; /* nonexistent channel */
- c->v2.remwindow += ssh2_pkt_getuint32();
+ while (1) {
+ int subsys;
+ char *cmd;
+
+ if (ssh_fallback_cmd) {
+ subsys = cfg.ssh_subsys2;
+ cmd = cfg.remote_cmd_ptr2;
+ } else {
+ subsys = cfg.ssh_subsys;
+ cmd = cfg.remote_cmd_ptr;
+ }
+
+ ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
+ ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
+ if (subsys) {
+ ssh2_pkt_addstring("subsystem");
+ ssh2_pkt_addbool(1); /* want reply */
+ ssh2_pkt_addstring(cmd);
+ } else if (*cmd) {
+ ssh2_pkt_addstring("exec");
+ ssh2_pkt_addbool(1); /* want reply */
+ ssh2_pkt_addstring(cmd);
+ } else {
+ ssh2_pkt_addstring("shell");
+ ssh2_pkt_addbool(1); /* want reply */
}
- } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
- if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
- if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
- bombout(("Server got confused by shell/command request"));
+ ssh2_pkt_send();
+ do {
+ crWaitUntilV(ispkt);
+ if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
+ unsigned i = ssh2_pkt_getuint32();
+ struct ssh_channel *c;
+ c = find234(ssh_channels, &i, ssh_channelfind);
+ if (!c)
+ continue; /* nonexistent channel */
+ c->v.v2.remwindow += ssh2_pkt_getuint32();
+ }
+ } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
+ if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
+ if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
+ bombout(("Server got confused by shell/command request"));
+ crReturnV;
+ }
+ /*
+ * We failed to start the command. If this is the
+ * fallback command, we really are finished; if it's
+ * not, and if the fallback command exists, try falling
+ * back to it before complaining.
+ */
+ if (!ssh_fallback_cmd && cfg.remote_cmd_ptr2 != NULL) {
+ logevent("Primary command failed; attempting fallback");
+ ssh_fallback_cmd = TRUE;
+ continue;
+ }
+ bombout(("Server refused to start a shell/command"));
crReturnV;
+ } else {
+ logevent("Started a shell/command");
}
- bombout(("Server refused to start a shell/command"));
- crReturnV;
- } else {
- logevent("Started a shell/command");
+ break;
}
ssh_state = SSH_STATE_SESSION;
continue; /* extended but not stderr */
ssh2_pkt_getstring(&data, &length);
if (data) {
+ int bufsize;
+ c->v.v2.locwindow -= length;
switch (c->type) {
case CHAN_MAINSESSION:
- from_backend(pktin.type ==
- SSH2_MSG_CHANNEL_EXTENDED_DATA, data,
- length);
+ bufsize =
+ from_backend(pktin.type ==
+ SSH2_MSG_CHANNEL_EXTENDED_DATA,
+ data, length);
break;
case CHAN_X11:
- x11_send(c->u.x11.s, data, length);
+ bufsize = x11_send(c->u.x11.s, data, length);
break;
case CHAN_SOCKDATA:
- pfd_send(c->u.pfd.s, data, length);
+ bufsize = pfd_send(c->u.pfd.s, data, length);
break;
case CHAN_AGENT:
while (length > 0) {
c->u.a.lensofar = 0;
}
}
+ bufsize = 0;
break;
}
/*
- * Enlarge the window again at the remote
- * side, just in case it ever runs down and
- * they fail to send us any more data.
+ * If we are not buffering too much data,
+ * enlarge the window again at the remote side.
*/
- ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
- ssh2_pkt_adduint32(c->remoteid);
- ssh2_pkt_adduint32(length);
- ssh2_pkt_send();
+ if (bufsize < OUR_V2_WINSIZE)
+ ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
}
} else if (pktin.type == SSH2_MSG_DISCONNECT) {
ssh_state = SSH_STATE_CLOSED;
break;
}
del234(ssh_channels, c);
- sfree(c->v2.outbuffer);
+ bufchain_clear(&c->v.v2.outbuffer);
sfree(c);
/*
c = find234(ssh_channels, &i, ssh_channelfind);
if (!c)
continue; /* nonexistent channel */
- c->v2.remwindow += ssh2_pkt_getuint32();
+ c->v.v2.remwindow += ssh2_pkt_getuint32();
try_send = TRUE;
} else if (pktin.type == SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
unsigned i = ssh2_pkt_getuint32();
c->remoteid = ssh2_pkt_getuint32();
c->type = CHAN_SOCKDATA;
c->closes = 0;
- c->v2.remwindow = ssh2_pkt_getuint32();
- c->v2.remmaxpkt = ssh2_pkt_getuint32();
- c->v2.outbuffer = NULL;
- c->v2.outbuflen = c->v2.outbufsize = 0;
+ c->v.v2.remwindow = ssh2_pkt_getuint32();
+ c->v.v2.remmaxpkt = ssh2_pkt_getuint32();
+ bufchain_init(&c->v.v2.outbuffer);
pfd_confirm(c->u.pfd.s);
} else if (pktin.type == SSH2_MSG_CHANNEL_OPEN) {
char *type;
} else {
c->localid = alloc_channel_id();
c->closes = 0;
- c->v2.remwindow = winsize;
- c->v2.remmaxpkt = pktsize;
- c->v2.outbuffer = NULL;
- c->v2.outbuflen = c->v2.outbufsize = 0;
+ c->v.v2.locwindow = OUR_V2_WINSIZE;
+ c->v.v2.remwindow = winsize;
+ c->v.v2.remmaxpkt = pktsize;
+ bufchain_init(&c->v.v2.outbuffer);
add234(ssh_channels, c);
ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
ssh2_pkt_adduint32(c->remoteid);
ssh2_pkt_adduint32(c->localid);
- ssh2_pkt_adduint32(0x8000UL); /* our window size */
+ ssh2_pkt_adduint32(c->v.v2.locwindow);
ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
ssh2_pkt_send();
}
/*
* Try to send data on all channels if we can.
*/
- for (i = 0; NULL != (c = index234(ssh_channels, i)); i++)
- ssh2_try_send(c);
+ for (i = 0; NULL != (c = index234(ssh_channels, i)); i++) {
+ int bufsize = ssh2_try_send(c);
+ if (bufsize == 0) {
+ switch (c->type) {
+ case CHAN_MAINSESSION:
+ /* stdin need not receive an unthrottle
+ * notification since it will be polled */
+ break;
+ case CHAN_X11:
+ x11_unthrottle(c->u.x11.s);
+ break;
+ case CHAN_AGENT:
+ /* agent sockets are request/response and need no
+ * buffer management */
+ break;
+ case CHAN_SOCKDATA:
+ pfd_unthrottle(c->u.pfd.s);
+ break;
+ }
+ }
+ }
}
}
ssh_send_ok = 0;
ssh_editing = 0;
ssh_echoing = 0;
+ ssh1_throttle_count = 0;
+ ssh_overall_bufsize = 0;
+ ssh_fallback_cmd = 0;
p = connect_to_host(host, port, realhost);
if (p != NULL)
/*
* Called to send data down the Telnet connection.
*/
-static void ssh_send(char *buf, int len)
+static int ssh_send(char *buf, int len)
{
if (s == NULL || ssh_protocol == NULL)
- return;
+ return 0;
ssh_protocol(buf, len, 0);
+
+ return ssh_sendbuffer();
+}
+
+/*
+ * Called to query the current amount of buffered stdin data.
+ */
+static int ssh_sendbuffer(void)
+{
+ int override_value;
+
+ if (s == NULL || ssh_protocol == NULL)
+ return 0;
+
+ /*
+ * If the SSH socket itself has backed up, add the total backup
+ * size on that to any individual buffer on the stdin channel.
+ */
+ override_value = 0;
+ if (ssh_throttled_all)
+ override_value = ssh_overall_bufsize;
+
+ if (ssh_version == 1) {
+ return override_value;
+ } else if (ssh_version == 2) {
+ if (!mainchan || mainchan->closes > 0)
+ return override_value;
+ else
+ return override_value + bufchain_size(&mainchan->v.v2.outbuffer);
+ }
+
+ return 0;
}
/*
return c;
}
+/*
+ * This is called when stdout/stderr (the entity to which
+ * from_backend sends data) manages to clear some backlog.
+ */
+void ssh_unthrottle(int bufsize)
+{
+ if (ssh_version == 1) {
+ if (bufsize < SSH1_BUFFER_LIMIT) {
+ ssh1_stdout_throttling = 0;
+ ssh1_throttle(-1);
+ }
+ } else {
+ if (mainchan && mainchan->closes == 0)
+ ssh2_set_window(mainchan, OUR_V2_WINSIZE - bufsize);
+ }
+}
+
void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
{
struct ssh_channel *c = (struct ssh_channel *)channel;
ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
ssh2_pkt_addstring("direct-tcpip");
ssh2_pkt_adduint32(c->localid);
- ssh2_pkt_adduint32(0x8000UL); /* our window size */
+ c->v.v2.locwindow = OUR_V2_WINSIZE;
+ ssh2_pkt_adduint32(c->v.v2.locwindow);/* our window size */
ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
ssh2_pkt_addstring(hostname);
ssh2_pkt_adduint32(port);
Backend ssh_backend = {
ssh_init,
ssh_send,
+ ssh_sendbuffer,
ssh_size,
ssh_special,
ssh_socket,
ssh_sendok,
ssh_ldisc,
+ ssh_unthrottle,
22
};
projects / u / mdw / putty / blobdiff