I know it works, but ...

[unix-history] / usr / src / lib / libc / net / rcmd.c

/*
* Copyright (c) 1983 Regents of the University of California.
* All rights reserved.  The Berkeley software License Agreement
* specifies the terms and conditions for redistribution.
*/

#ifndef lint
static char sccsid[] = "@(#)rcmd.c      5.7 (Berkeley) %G%";
#endif not lint

#include <stdio.h>
#include <ctype.h>
#include <pwd.h>
#include <sys/param.h>
#include <sys/socket.h>
#include <sys/stat.h>

#include <netinet/in.h>

#include <netdb.h>
#include <errno.h>

extern  errno;
char    *index(), *sprintf();

rcmd(ahost, rport, locuser, remuser, cmd, fd2p)
       char **ahost;
       int rport;
       char *locuser, *remuser, *cmd;
       int *fd2p;
{
       int s, timo = 1;
       struct sockaddr_in sin, sin2, from;
       char c;
       int lport = IPPORT_RESERVED - 1;
       struct hostent *hp;

       hp = gethostbyname(*ahost);
       if (hp == 0) {
               fprintf(stderr, "%s: unknown host\n", *ahost);
               return (-1);
       }
       *ahost = hp->h_name;
retry:
       s = rresvport(&lport);
       if (s < 0) {
               if (errno == EAGAIN)
                       fprintf(stderr, "socket: All ports in use\n");
               else
                       perror("rcmd: socket");
               return (-1);
       }
       sin.sin_family = hp->h_addrtype;
       bcopy(hp->h_addr, (caddr_t)&sin.sin_addr, hp->h_length);
       sin.sin_port = rport;
       if (connect(s, (caddr_t)&sin, sizeof (sin), 0) < 0) {
               (void) close(s);
               if (errno == EADDRINUSE) {
                       lport--;
                       goto retry;
               }
               if (errno == ECONNREFUSED && timo <= 16) {
                       sleep(timo);
                       timo *= 2;
                       goto retry;
               }
               perror(hp->h_name);
               return (-1);
       }
       lport--;
       if (fd2p == 0) {
               write(s, "", 1);
               lport = 0;
       } else {
               char num[8];
               int s2 = rresvport(&lport), s3;
               int len = sizeof (from);

               if (s2 < 0)
                       goto bad;
               listen(s2, 1);
               (void) sprintf(num, "%d", lport);
               if (write(s, num, strlen(num)+1) != strlen(num)+1) {
                       perror("write: setting up stderr");
                       (void) close(s2);
                       goto bad;
               }
               s3 = accept(s2, &from, &len, 0);
               (void) close(s2);
               if (s3 < 0) {
                       perror("accept");
                       lport = 0;
                       goto bad;
               }
               *fd2p = s3;
               from.sin_port = ntohs((u_short)from.sin_port);
               if (from.sin_family != AF_INET ||
                   from.sin_port >= IPPORT_RESERVED) {
                       fprintf(stderr,
                           "socket: protocol failure in circuit setup.\n");
                       goto bad2;
               }
       }
       (void) write(s, locuser, strlen(locuser)+1);
       (void) write(s, remuser, strlen(remuser)+1);
       (void) write(s, cmd, strlen(cmd)+1);
       if (read(s, &c, 1) != 1) {
               perror(*ahost);
               goto bad2;
       }
       if (c != 0) {
               while (read(s, &c, 1) == 1) {
                       (void) write(2, &c, 1);
                       if (c == '\n')
                               break;
               }
               goto bad2;
       }
       return (s);
bad2:
       if (lport)
               (void) close(*fd2p);
bad:
       (void) close(s);
       return (-1);
}

rresvport(alport)
       int *alport;
{
       struct sockaddr_in sin;
       int s;

       sin.sin_family = AF_INET;
       sin.sin_addr.s_addr = INADDR_ANY;
       s = socket(AF_INET, SOCK_STREAM, 0);
       if (s < 0)
               return (-1);
       for (;;) {
               sin.sin_port = htons((u_short)*alport);
               if (bind(s, (caddr_t)&sin, sizeof (sin), 0) >= 0)
                       return (s);
               if (errno != EADDRINUSE) {
                       (void) close(s);
                       return (-1);
               }
               (*alport)--;
               if (*alport == IPPORT_RESERVED/2) {
                       (void) close(s);
                       errno = EAGAIN;         /* close */
                       return (-1);
               }
       }
}

ruserok(rhost, superuser, ruser, luser)
       char *rhost;
       int superuser;
       char *ruser, *luser;
{
       FILE *hostf;
       char fhost[MAXHOSTNAMELEN];
       char ahost[MAXHOSTNAMELEN];
       int first = 1;
       register char *sp, *p;
       int baselen = -1;

       sp = rhost;
       p = fhost;
       while (*sp) {
               if (*sp == '.') {
                       if (baselen == -1)
                               baselen = sp - rhost;
                       *p++ = *sp++;
               } else {
                       *p++ = isupper(*sp) ? tolower(*sp++) : *sp++;
               }
       }
       *p = '\0';
       hostf = superuser ? (FILE *)0 : fopen("/etc/hosts.equiv", "r");
again:
       if (hostf) {
               while (fgets(ahost, sizeof (ahost), hostf)) {
                       char *user;

                       p = ahost;
                       while (*p != '\n' && *p != ' ' && *p != '\t' && *p != '\0')
                               *p++ = isupper(*p) ? tolower(*p) : *p;
                       if (*p == ' ' || *p == '\t') {
                               *p++ = '\0';
                               while (*p == ' ' || *p == '\t')
                                       p++;
                               user = p;
                               while (*p != '\n' && *p != ' ' && *p != '\t' && *p != '\0')
                                       p++;
                       } else
                               user = p;
                       *p = '\0';
                       if (_checkhost(fhost, ahost, baselen) &&
                           !strcmp(ruser, *user ? user : luser)) {
                               (void) fclose(hostf);
                               return (0);
                       }
               }
               (void) fclose(hostf);
       }
       if (first == 1) {
               struct stat sbuf;
               struct passwd *pwd;
               char pbuf[MAXPATHLEN];

               first = 0;
               if ((pwd = getpwnam(luser)) == NULL)
                       return(-1);
               (void)strcpy(pbuf, pwd->pw_dir);
               (void)strcat(pbuf, "/.rhosts");
               if ((hostf = fopen(pbuf, "r")) == NULL)
                       return(-1);
               (void)fstat(fileno(hostf), &sbuf);
               if (sbuf.st_uid && sbuf.st_uid != pwd->pw_uid) {
                       fclose(hostf);
                       return(-1);
               }
               goto again;
       }
       return (-1);
}

_checkhost(rhost, lhost, len)
char *rhost, *lhost;
int len;
{
       static char ldomain[MAXHOSTNAMELEN + 1];
       static char *domainp = NULL;
       register char *cp;

       if (len == -1)
               return(!strcmp(rhost, lhost));
       if (strncmp(rhost, lhost, len))
               return(0);
       if (!strcmp(rhost, lhost))
               return(1);
       if (*(lhost + len) != '\0')
               return(0);
       if (!domainp) {
               if (gethostname(ldomain, sizeof(ldomain)) == -1) {
                       domainp = (char *)1;
                       return(0);
               }
               ldomain[MAXHOSTNAMELEN] = NULL;
               if ((domainp = index(ldomain, '.') + 1) == (char *)1)
                       return(0);
               cp = domainp;
               while (*cp)
                       *cp++ = isupper(*cp) ? tolower(*cp) : *cp;
       }
       if (domainp == (char *)1)
               return(0);
       return(!strcmp(domainp, rhost + len +1));
}