diff options
Diffstat (limited to 'unix/os/net/rexec.c')
| -rw-r--r-- | unix/os/net/rexec.c | 160 |
1 files changed, 160 insertions, 0 deletions
diff --git a/unix/os/net/rexec.c b/unix/os/net/rexec.c new file mode 100644 index 00000000..4f851fb9 --- /dev/null +++ b/unix/os/net/rexec.c @@ -0,0 +1,160 @@ +/* Copyright(c) 1986 Association of Universities for Research in Astronomy Inc. + */ + +#include "types.h" +#include "socket.h" +#include "in.h" +#include "netdb.h" + +/* TCP_REXEC -- Execute a command on a remote node via the network. This is + * an implementation of the Berkeley UNIX procedure of the same name for a + * machine independent TCP network interface. Unlike the UNIX rexec, + * however, we require that the user login name and password be given as + * input arguments, in addition to the host name and port number and the + * command to be executed. + * + * REXEC assumes that it is talking to an REXECD server on the remote node. + * The TCP EXEC port on the remote node spawns the REXECD server which reads and + * authenticates the user login and password, sets up the error socket if so + * indicated, changes the current directory to the user's home directory, and + * then executes the command. The command syntax is determined by the shell + * REXECD spawns to execute the command, and is implementation dependent. + * Currently the REXECD daemons are either UNIX hosted or UNIX emulated, hence + * the command syntax is the UNIX shell (Bourne shell usually). The command + * executes with its standard input and output (and error output if fd2p=0) + * connected to the socket returned by REXEC. + * + * Note that the shell spawned by the REXEC daemon may be used to spawn a user + * specified server process using a shell command, e.g. "run server.e arg arg". + * In this case the daemon is used to login and set the current directory and + * pass args to the user server, at the expense of one additional process spawn + * for the shell. + */ +tcp_rexec (ahost, rport, name, pass, cmd, fd2p) +char **ahost; /* alias of server node */ +int rport; /* IP port number (for EXEC) */ +char *name, *pass; /* user login and password */ +char *cmd; /* command to be executed */ +int *fd2p; /* error channel */ +{ + struct hostent *tcp_gethostbyname(); + struct sockaddr_in sin, sin2, from; + struct hostent *hp; + int timo = 1; + u_sock s, s3; + char c; + short port; +eprintf("rexec %s %s %s %s\n", *ahost, name, pass, cmd); + + /* Read host name table for the local network to get the internet + * address of the named host. + */ + hp = tcp_gethostbyname (*ahost); + if (hp == 0) { + ku_error ("unknown network host"); + return (-1); + } + + /* Set up a full duplex TCP socket to the TCP/EXEC server process + * on the remote node. + */ +retry: + s = tcp_socket (AF_INET, SOCK_STREAM, 0); + if (s < 0) { + ku_error ("rexec: cannot make socket"); + return (-1); + } + + sin.sin_family = hp->h_addrtype; + sin.sin_port = rport; + ku_bcopy (hp->h_addr, (caddr_t)&sin.sin_addr, hp->h_length); + + if (tcp_connect (s, &sin, sizeof(sin)) < 0) { + if (timo <= 16) { + tcp_close (s); + ku_sleep (timo); + timo *= 2; + goto retry; + } + ku_error ("rexec: connect failure"); + return (-1); + } + + /* If no output error channel variable was given instruct the REXECD + * server to return error output on the data socket, else open a second + * socket to be used for error communications and signals. + */ + if (fd2p == 0) { + tcp_write (s, "", 1); + port = 0; + + } else { + char *num, *ku_itoc(); + int sin2len, len; + u_sock s2; + + s2 = tcp_socket (AF_INET, SOCK_STREAM, 0); + if (s2 < 0) { + tcp_close (s); + return (-1); + } + + tcp_listen (s2, 1); + + sin2len = sizeof (sin2); + if (tcp_gsockname (s2, (char *)&sin2, &sin2len) < 0 || + sin2len != sizeof (sin2)) { + + ku_error ("rexec: getsockname failed"); + tcp_close (s2); + goto bad; + } + + port = htons ((u_short)sin2.sin_port); + num = ku_itoc (port); + tcp_write (s, num, strlen(num)+1); + len = sizeof (from); + + s3 = tcp_accept (s2, &from, &len, 0); + + tcp_close (s2); + if (s3 < 0) { + ku_error ("rexec: accept failure"); + port = 0; + goto bad; + } + + *fd2p = s3; + } + + tcp_write (s, name, strlen (name) + 1); + tcp_write (s, pass, strlen (pass) + 1); + tcp_write (s, cmd, strlen (cmd) + 1); + + if (tcp_read (s, &c, 1) != 1) { + ku_error ("rexec: cannot read server"); + goto bad; + } + + /* Read error message from server process. + */ + if (c != 0) { + char lbuf[80]; + char *op; + + for (op=lbuf; (tcp_read (s, op, 1) == 1); op++) + if (*op == '\n') + break; + *op = '\0'; + ku_error (lbuf); + goto bad; + } + + return (s); +bad: + if (port) + tcp_close (*fd2p); + tcp_close (s); + + return (-1); +} |