ref: a291bbdeddfd41a2f0907ecbd7b819f0eedffdaf
dir: /sys/src/cmd/ssh/ssh.c/
#include "ssh.h"
int cooked = 0; /* user wants cooked mode */
int raw = 0; /* console is in raw mode */
int crstrip;
int interactive = -1;
int usemenu = 1;
int isatty(int);
int rawhack;
int forwardagent = 0;
char *buildcmd(int, char**);
void fromnet(Conn*);
void fromstdin(Conn*);
void winchanges(Conn*);
static void sendwritemsg(Conn *c, char *buf, int n);
Cipher *allcipher[] = {
&cipherrc4,
&cipherblowfish,
&cipher3des,
&cipherdes,
&ciphernone,
&ciphertwiddle,
};
Auth *allauth[] = {
&authpassword,
&authrsa,
&authtis,
};
char *cipherlist = "blowfish rc4 3des";
char *authlist = "rsa password tis";
Cipher*
findcipher(char *name, Cipher **list, int nlist)
{
int i;
for(i=0; i<nlist; i++)
if(strcmp(name, list[i]->name) == 0)
return list[i];
error("unknown cipher %s", name);
return nil;
}
Auth*
findauth(char *name, Auth **list, int nlist)
{
int i;
for(i=0; i<nlist; i++)
if(strcmp(name, list[i]->name) == 0)
return list[i];
error("unknown auth %s", name);
return nil;
}
void
usage(void)
{
fprint(2, "usage: ssh [-CiImPpRr] [-A authlist] [-c cipherlist] [user@]hostname [cmd [args]]\n");
exits("usage");
}
void
main(int argc, char **argv)
{
int i, dowinchange, fd, usepty;
char *host, *cmd, *user, *p;
char *f[16];
Conn c;
Msg *m;
fmtinstall('B', mpfmt);
fmtinstall('H', encodefmt);
atexit(atexitkiller);
atexitkill(getpid());
dowinchange = 0;
if(getenv("LINES"))
dowinchange = 1;
usepty = -1;
user = nil;
ARGBEGIN{
case 'B': /* undocumented, debugging */
doabort = 1;
break;
case 'D': /* undocumented, debugging */
debuglevel = strtol(EARGF(usage()), nil, 0);
break;
case 'l': /* deprecated */
case 'u':
user = EARGF(usage());
break;
case 'a': /* used by Unix scp implementations; we must ignore them. */
case 'x':
break;
case 'A':
authlist = EARGF(usage());
break;
case 'C':
cooked = 1;
break;
case 'c':
cipherlist = EARGF(usage());
break;
case 'f':
forwardagent = 1;
break;
case 'I':
interactive = 0;
break;
case 'i':
interactive = 1;
break;
case 'm':
usemenu = 0;
break;
case 'P':
usepty = 0;
break;
case 'p':
usepty = 1;
break;
case 'R':
rawhack = 1;
break;
case 'r':
crstrip = 1;
break;
default:
usage();
}ARGEND
if(argc < 1)
usage();
host = argv[0];
cmd = nil;
if(argc > 1)
cmd = buildcmd(argc-1, argv+1);
if((p = strchr(host, '@')) != nil){
*p++ = '\0';
user = host;
host = p;
}
if(user == nil)
user = getenv("user");
if(user == nil)
sysfatal("cannot find user name");
privatefactotum();
if(interactive==-1)
interactive = isatty(0);
if((fd = dial(netmkaddr(host, "tcp", "ssh"), nil, nil, nil)) < 0)
sysfatal("dialing %s: %r", host);
memset(&c, 0, sizeof c);
c.interactive = interactive;
c.fd[0] = c.fd[1] = fd;
c.user = user;
c.host = host;
setaliases(&c, host);
c.nokcipher = getfields(cipherlist, f, nelem(f), 1, ", ");
c.okcipher = emalloc(sizeof(Cipher*)*c.nokcipher);
for(i=0; i<c.nokcipher; i++)
c.okcipher[i] = findcipher(f[i], allcipher, nelem(allcipher));
c.nokauth = getfields(authlist, f, nelem(f), 1, ", ");
c.okauth = emalloc(sizeof(Auth*)*c.nokauth);
for(i=0; i<c.nokauth; i++)
c.okauth[i] = findauth(f[i], allauth, nelem(allauth));
sshclienthandshake(&c);
if(forwardagent){
if(startagent(&c) < 0)
forwardagent = 0;
}
if(usepty == -1)
usepty = cmd==nil;
if(usepty)
requestpty(&c);
if(cmd){
m = allocmsg(&c, SSH_CMSG_EXEC_CMD, 4+strlen(cmd));
putstring(m, cmd);
}else
m = allocmsg(&c, SSH_CMSG_EXEC_SHELL, 0);
sendmsg(m);
fromstdin(&c);
rfork(RFNOTEG); /* only fromstdin gets notes */
if(dowinchange)
winchanges(&c);
fromnet(&c);
exits(0);
}
int
isatty(int fd)
{
char buf[64];
buf[0] = '\0';
fd2path(fd, buf, sizeof buf);
if(strlen(buf)>=9 && strcmp(buf+strlen(buf)-9, "/dev/cons")==0)
return 1;
return 0;
}
char*
buildcmd(int argc, char **argv)
{
int i, len;
char *s, *t;
len = argc-1;
for(i=0; i<argc; i++)
len += strlen(argv[i]);
s = emalloc(len+1);
t = s;
for(i=0; i<argc; i++){
if(i)
*t++ = ' ';
strcpy(t, argv[i]);
t += strlen(t);
}
return s;
}
void
fromnet(Conn *c)
{
int fd, len;
char *s, *es, *r, *w;
ulong ex;
char buf[64];
Msg *m;
for(;;){
m = recvmsg(c, -1);
if(m == nil)
break;
switch(m->type){
default:
badmsg(m, 0);
case SSH_SMSG_EXITSTATUS:
ex = getlong(m);
if(ex==0)
exits(0);
sprint(buf, "%lud", ex);
exits(buf);
case SSH_MSG_DISCONNECT:
s = getstring(m);
error("disconnect: %s", s);
/*
* If we ever add reverse port forwarding, we'll have to
* revisit this. It assumes that the agent connections are
* the only ones.
*/
case SSH_SMSG_AGENT_OPEN:
if(!forwardagent)
error("server tried to use agent forwarding");
handleagentopen(m);
break;
case SSH_MSG_CHANNEL_INPUT_EOF:
if(!forwardagent)
error("server tried to use agent forwarding");
handleagentieof(m);
break;
case SSH_MSG_CHANNEL_OUTPUT_CLOSED:
if(!forwardagent)
error("server tried to use agent forwarding");
handleagentoclose(m);
break;
case SSH_MSG_CHANNEL_DATA:
if(!forwardagent)
error("server tried to use agent forwarding");
handleagentmsg(m);
break;
case SSH_SMSG_STDOUT_DATA:
fd = 1;
goto Dataout;
case SSH_SMSG_STDERR_DATA:
fd = 2;
goto Dataout;
Dataout:
len = getlong(m);
s = (char*)getbytes(m, len);
if(crstrip){
es = s+len;
for(r=w=s; r<es; r++)
if(*r != '\r')
*w++ = *r;
len = w-s;
}
write(fd, s, len);
break;
}
free(m);
}
}
/*
* Lifted from telnet.c, con.c
*/
static int consctl = -1;
static int outfd1=1, outfd2=2; /* changed during system */
static void system(Conn*, char*);
/*
* turn keyboard raw mode on
*/
static void
rawon(void)
{
if(raw)
return;
if(cooked)
return;
if(consctl < 0)
consctl = open("/dev/consctl", OWRITE);
if(consctl < 0)
return;
if(write(consctl, "rawon", 5) != 5)
return;
raw = 1;
}
/*
* turn keyboard raw mode off
*/
static void
rawoff(void)
{
if(raw == 0)
return;
if(consctl < 0)
return;
if(write(consctl, "rawoff", 6) != 6)
return;
close(consctl);
consctl = -1;
raw = 0;
}
/*
* control menu
*/
#define STDHELP "\t(q)uit, (i)nterrupt, toggle printing (r)eturns, (.)continue, (!cmd)\n"
static int
menu(Conn *c)
{
char buf[1024];
long n;
int done;
int wasraw;
wasraw = raw;
if(wasraw)
rawoff();
buf[0] = '?';
fprint(2, ">>> ");
for(done = 0; !done; ){
n = read(0, buf, sizeof(buf)-1);
if(n <= 0)
return -1;
buf[n] = 0;
switch(buf[0]){
case '!':
print(buf);
system(c, buf+1);
print("!\n");
done = 1;
break;
case 'i':
buf[0] = 0x1c;
sendwritemsg(c, buf, 1);
done = 1;
break;
case '.':
case 'q':
done = 1;
break;
case 'r':
crstrip = 1-crstrip;
done = 1;
break;
default:
fprint(2, STDHELP);
break;
}
if(!done)
fprint(2, ">>> ");
}
if(wasraw)
rawon();
else
rawoff();
return buf[0];
}
static void
sendwritemsg(Conn *c, char *buf, int n)
{
Msg *m;
if(n==0)
m = allocmsg(c, SSH_CMSG_EOF, 0);
else{
m = allocmsg(c, SSH_CMSG_STDIN_DATA, 4+n);
putlong(m, n);
putbytes(m, buf, n);
}
sendmsg(m);
}
/*
* run a command with the network connection as standard IO
*/
static void
system(Conn *c, char *cmd)
{
int pid;
int p;
int pfd[2];
int n;
int wasconsctl;
char buf[4096];
if(pipe(pfd) < 0){
perror("pipe");
return;
}
outfd1 = outfd2 = pfd[1];
wasconsctl = consctl;
close(consctl);
consctl = -1;
switch(pid = fork()){
case -1:
perror("con");
return;
case 0:
close(pfd[1]);
dup(pfd[0], 0);
dup(pfd[0], 1);
close(c->fd[0]); /* same as c->fd[1] */
close(pfd[0]);
if(*cmd)
execl("/bin/rc", "rc", "-c", cmd, nil);
else
execl("/bin/rc", "rc", nil);
perror("con");
exits("exec");
break;
default:
close(pfd[0]);
while((n = read(pfd[1], buf, sizeof(buf))) > 0)
sendwritemsg(c, buf, n);
p = waitpid();
outfd1 = 1;
outfd2 = 2;
close(pfd[1]);
if(p < 0 || p != pid)
return;
break;
}
if(wasconsctl >= 0){
consctl = open("/dev/consctl", OWRITE);
if(consctl < 0)
error("cannot open consctl");
}
}
static void
cookedcatchint(void*, char *msg)
{
if(strstr(msg, "interrupt"))
noted(NCONT);
else if(strstr(msg, "kill"))
noted(NDFLT);
else
noted(NCONT);
}
static int
wasintr(void)
{
char err[64];
rerrstr(err, sizeof err);
return strstr(err, "interrupt") != 0;
}
void
fromstdin(Conn *c)
{
int n;
char buf[1024];
int pid;
int eofs;
switch(pid = rfork(RFMEM|RFPROC|RFNOWAIT)){
case -1:
error("fork: %r");
case 0:
break;
default:
atexitkill(pid);
return;
}
atexit(atexitkiller);
if(interactive)
rawon();
notify(cookedcatchint);
eofs = 0;
for(;;){
n = read(0, buf, sizeof(buf));
if(n < 0){
if(wasintr()){
if(!raw){
buf[0] = 0x7f;
n = 1;
}else
continue;
}else
break;
}
if(n == 0){
if(!c->interactive || ++eofs > 32)
break;
}else
eofs = 0;
if(interactive && usemenu && n && memchr(buf, 0x1c, n)) {
if(menu(c)=='q'){
sendwritemsg(c, "", 0);
exits("quit");
}
continue;
}
if(!raw && n==0){
buf[0] = 0x4;
n = 1;
}
sendwritemsg(c, buf, n);
}
sendwritemsg(c, "", 0);
atexitdont(atexitkiller);
exits(nil);
}
void
winchanges(Conn *c)
{
int nrow, ncol, width, height;
int pid;
switch(pid = rfork(RFMEM|RFPROC|RFNOWAIT)){
case -1:
error("fork: %r");
case 0:
break;
default:
atexitkill(pid);
return;
}
for(;;){
if(readgeom(&nrow, &ncol, &width, &height) < 0)
break;
sendwindowsize(c, nrow, ncol, width, height);
}
exits(nil);
}