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glibc  2.9
Functions | Variables
rcmd.c File Reference
#include <sys/param.h>
#include <sys/poll.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <alloca.h>
#include <signal.h>
#include <fcntl.h>
#include <netdb.h>
#include <unistd.h>
#include <pwd.h>
#include <errno.h>
#include <stdio.h>
#include <stdio_ext.h>
#include <ctype.h>
#include <string.h>
#include <libintl.h>
#include <stdlib.h>
#include <wchar.h>
#include <sys/uio.h>

Go to the source code of this file.

Functions

int __ivaliduser (FILE *, u_int32_t, const char *, const char *)
static int __validuser2_sa (FILE *, struct sockaddr *, size_t, const char *, const char *, const char *)
static int ruserok2_sa (struct sockaddr *ra, size_t ralen, int superuser, const char *ruser, const char *luser, const char *rhost)
static int ruserok_sa (struct sockaddr *ra, size_t ralen, int superuser, const char *ruser, const char *luser)
int iruserok_af (const void *raddr, int superuser, const char *ruser, const char *luser, sa_family_t af)
int iruserok (u_int32_t raddr, int superuser, const char *ruser, const char *luser)
 libc_hidden_proto (iruserok_af)
 libc_hidden_def (rcmd_af)
int rresvport_af (int *alport, sa_family_t family)
 libc_hidden_def (rresvport_af)
int ruserok_af (char *rhost, int superuser, char *ruser, char *luser, sa_family_t af) const
 libc_hidden_def (ruserok_af)
static FILEiruserfopen (const char *file, uid_t okuser)
int iruserok_af (void *raddr, int superuser, const char *ruser, const char *luser, sa_family_t af) const
 libc_hidden_def (iruserok_af)
static int internal_function __checkhost_sa (struct sockaddr *ra, size_t ralen, char *lhost, const char *rhost)
static int internal_function __icheckuser (const char *luser, const char *ruser)
static int __isempty (char *p)

Variables

int __check_rhosts_file = 1
char * __rcmd_errstr

Function Documentation

static int internal_function __checkhost_sa ( struct sockaddr ra,
size_t  ralen,
char *  lhost,
const char *  rhost 
) [static]

Definition at line 664 of file rcmd.c.

{
       struct addrinfo hints, *res0, *res;
       char raddr[INET6_ADDRSTRLEN];
       int match;
       int negate=1;    /* Multiply return with this to get -1 instead of 1 */

       /* Check nis netgroup.  */
       if (strncmp ("+@", lhost, 2) == 0)
              return innetgr (&lhost[2], rhost, NULL, NULL);

       if (strncmp ("-@", lhost, 2) == 0)
              return -innetgr (&lhost[2], rhost, NULL, NULL);

       /* -host */
       if (strncmp ("-", lhost,1) == 0) {
              negate = -1;
              lhost++;
       } else if (strcmp ("+",lhost) == 0) {
              return 1;                    /* asking for trouble, but ok.. */
       }

       /* Try for raw ip address first. */
       /* XXX */
       if (getnameinfo(ra, ralen,
                     raddr, sizeof(raddr), NULL, 0,
                     NI_NUMERICHOST) == 0
           && strcmp(raddr, lhost) == 0)
              return negate;

       /* Better be a hostname. */
       match = 0;
       memset(&hints, '\0', sizeof(hints));
       hints.ai_family = ra->sa_family;
       if (getaddrinfo(lhost, NULL, &hints, &res0) == 0){
              /* Spin through ip addresses. */
              for (res = res0; res; res = res->ai_next)
                {
                  if (res->ai_family == ra->sa_family
                     && !memcmp(res->ai_addr, ra, res->ai_addrlen))
                    {
                     match = 1;
                     break;
                    }
                }
              freeaddrinfo (res0);
       }
       return negate * match;
}

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static int internal_function __icheckuser ( const char *  luser,
const char *  ruser 
) [static]

Definition at line 718 of file rcmd.c.

{
    /*
      luser is user entry from .rhosts/hosts.equiv file
      ruser is user id on remote host
      */

    /* [-+]@netgroup */
    if (strncmp ("+@", luser, 2) == 0)
       return innetgr (&luser[2], NULL, ruser, NULL);

    if (strncmp ("-@", luser,2) == 0)
       return -innetgr (&luser[2], NULL, ruser, NULL);

    /* -user */
    if (strncmp ("-", luser, 1) == 0)
       return -(strcmp (&luser[1], ruser) == 0);

    /* + */
    if (strcmp ("+", luser) == 0)
       return 1;

    /* simple string match */
    return strcmp (ruser, luser) == 0;
}

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static int __isempty ( char *  p) [static]

Definition at line 748 of file rcmd.c.

{
    while (*p && isspace (*p)) {
       ++p;
    }

    return (*p == '\0' || *p == '#') ? 1 : 0 ;
}

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int __ivaliduser ( FILE hostf,
u_int32_t  raddr,
const char *  luser,
const char *  ruser 
)

Definition at line 647 of file rcmd.c.

{
       struct sockaddr_in ra;
       memset(&ra, '\0', sizeof(ra));
       ra.sin_family = AF_INET;
       ra.sin_addr.s_addr = raddr;
       return __validuser2_sa(hostf, (struct sockaddr *)&ra, sizeof(ra),
                            luser, ruser, "-");
}

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static int __validuser2_sa ( FILE hostf,
struct sockaddr ra,
size_t  ralen,
const char *  luser,
const char *  ruser,
const char *  rhost 
) [static]

Definition at line 761 of file rcmd.c.

{
    register const char *user;
    register char *p;
    int hcheck, ucheck;
    char *buf = NULL;
    size_t bufsize = 0;
    int retval = -1;

    while (__getline (&buf, &bufsize, hostf) > 0) {
       buf[bufsize - 1] = '\0'; /* Make sure it's terminated.  */
        p = buf;

       /* Skip empty or comment lines */
       if (__isempty (p)) {
           continue;
       }

       for (;*p && !isspace(*p); ++p) {
           *p = _tolower (*p);
       }

       /* Next we want to find the permitted name for the remote user.  */
       if (*p == ' ' || *p == '\t') {
           /* <nul> terminate hostname and skip spaces */
           for (*p++='\0'; *p && isspace (*p); ++p);

           user = p;                   /* this is the user's name */
           while (*p && !isspace (*p))
              ++p;                    /* find end of user's name */
       } else
           user = p;

       *p = '\0';              /* <nul> terminate username (+host?) */

       /* buf -> host(?) ; user -> username(?) */

       /* First check host part */
       hcheck = __checkhost_sa (ra, ralen, buf, rhost);

       if (hcheck < 0)
           break;

       if (hcheck) {
           /* Then check user part */
           if (! (*user))
              user = luser;

           ucheck = __icheckuser (user, ruser);

           /* Positive 'host user' match? */
           if (ucheck > 0) {
              retval = 0;
              break;
           }

           /* Negative 'host -user' match? */
           if (ucheck < 0)
              break;

           /* Neither, go on looking for match */
       }
    }

    free (buf);

    return retval;
}

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static FILE* iruserfopen ( const char *  file,
uid_t  okuser 
) [static]

Definition at line 471 of file rcmd.c.

{
  struct stat64 st;
  char *cp = NULL;
  FILE *res = NULL;

  /* If not a regular file, if owned by someone other than user or
     root, if writeable by anyone but the owner, or if hardlinked
     anywhere, quit.  */
  if (__lxstat64 (_STAT_VER, file, &st))
    cp = _("lstat failed");
  else if (!S_ISREG (st.st_mode))
    cp = _("not regular file");
  else
    {
      res = fopen (file, "rc");
      if (!res)
       cp = _("cannot open");
      else if (__fxstat64 (_STAT_VER, fileno (res), &st) < 0)
       cp = _("fstat failed");
      else if (st.st_uid && st.st_uid != okuser)
       cp = _("bad owner");
      else if (st.st_mode & (S_IWGRP|S_IWOTH))
       cp = _("writeable by other than owner");
      else if (st.st_nlink > 1)
       cp = _("hard linked somewhere");
    }

  /* If there were any problems, quit.  */
  if (cp != NULL)
    {
      __rcmd_errstr = cp;
      if (res)
       fclose (res);
      return NULL;
    }

  /* No threads use this stream.  */
  __fsetlocking (res, FSETLOCKING_BYCALLER);

  return res;
}

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int iruserok ( u_int32_t  raddr,
int  superuser,
const char *  ruser,
const char *  luser 
)
int iruserok_af ( const void *  raddr,
int  superuser,
const char *  ruser,
const char *  luser,
sa_family_t  af 
)

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int iruserok_af ( void *  raddr,
int  superuser,
const char *  ruser,
const char *  luser,
sa_family_t  af 
) const

Definition at line 596 of file rcmd.c.

{
  struct sockaddr_storage ra;
  size_t ralen;

  memset (&ra, '\0', sizeof(ra));
  switch (af){
  case AF_INET:
    ((struct sockaddr_in *)&ra)->sin_family = AF_INET;
    memcpy (&(((struct sockaddr_in *)&ra)->sin_addr), raddr,
           sizeof(struct in_addr));
    ralen = sizeof(struct sockaddr_in);
    break;
  case AF_INET6:
    ((struct sockaddr_in6 *)&ra)->sin6_family = AF_INET6;
    memcpy (&(((struct sockaddr_in6 *)&ra)->sin6_addr), raddr,
            sizeof(struct in6_addr));
    ralen = sizeof(struct sockaddr_in6);
    break;
  default:
    return 0;
  }
  return ruserok_sa ((struct sockaddr *)&ra, ralen, superuser, ruser, luser);
}

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libc_hidden_def ( rcmd_af  )

Definition at line 355 of file rcmd.c.

{
  return rcmd_af (ahost, rport, locuser, remuser, cmd, fd2p, AF_INET);
}

Definition at line 422 of file rcmd.c.

{
       return rresvport_af(alport, AF_INET);
}

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Definition at line 459 of file rcmd.c.

{
       return ruserok_af(rhost, superuser, ruser, luser, AF_INET);
}

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Definition at line 624 of file rcmd.c.

{
  return iruserok_af (&raddr, superuser, ruser, luser, AF_INET);
}

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Definition at line 101 of file rcmd.c.

{
       char paddr[INET6_ADDRSTRLEN];
       struct addrinfo hints, *res, *ai;
       struct sockaddr_storage from;
       struct pollfd pfd[2];
       int32_t oldmask;
       pid_t pid;
       int s, lport, timo, error;
       char c;
       int refused;
       char num[8];
       ssize_t n;

       if (af != AF_INET && af != AF_INET6 && af != AF_UNSPEC)
         {
           __set_errno (EAFNOSUPPORT);
           return -1;
         }

       pid = __getpid();

       memset(&hints, '\0', sizeof(hints));
       hints.ai_flags = AI_CANONNAME;
       hints.ai_family = af;
       hints.ai_socktype = SOCK_STREAM;
       (void)__snprintf(num, sizeof(num), "%d", ntohs(rport));
       error = getaddrinfo(*ahost, num, &hints, &res);
       if (error) {
              if (error == EAI_NONAME && *ahost != NULL)
                     __fxprintf(NULL, "%s: Unknown host\n", *ahost);
              else
                     __fxprintf(NULL, "rcmd: getaddrinfo: %s\n",
                               gai_strerror(error));

                return -1;
       }

       pfd[0].events = POLLIN;
       pfd[1].events = POLLIN;

       if (res->ai_canonname){
              free (ahostbuf);
              ahostbuf = strdup (res->ai_canonname);
              if (ahostbuf == NULL) {
                     __fxprintf(NULL, "%s",
                               _("rcmd: Cannot allocate memory\n"));
                     return -1;
              }
              *ahost = ahostbuf;
       } else
              *ahost = NULL;
       ai = res;
       refused = 0;
       oldmask = __sigblock(sigmask(SIGURG));
       for (timo = 1, lport = IPPORT_RESERVED - 1;;) {
              char errbuf[200];

              s = rresvport_af(&lport, ai->ai_family);
              if (s < 0) {
                     if (errno == EAGAIN)
                            __fxprintf(NULL, "%s", _("\
rcmd: socket: All ports in use\n"));
                     else
                            __fxprintf(NULL, "rcmd: socket: %m\n");

                     __sigsetmask(oldmask);
                     freeaddrinfo(res);
                     return -1;
              }
              __fcntl(s, F_SETOWN, pid);
              if (__connect(s, ai->ai_addr, ai->ai_addrlen) >= 0)
                     break;
              (void)__close(s);
              if (errno == EADDRINUSE) {
                     lport--;
                     continue;
              }
              if (errno == ECONNREFUSED)
                     refused = 1;
              if (ai->ai_next != NULL) {
                     int oerrno = errno;
                     char *buf = NULL;

                     getnameinfo(ai->ai_addr, ai->ai_addrlen,
                                paddr, sizeof(paddr),
                                NULL, 0,
                                NI_NUMERICHOST);

                     if (__asprintf (&buf, _("connect to address %s: "),
                                   paddr) >= 0)
                       {
                         __fxprintf(NULL, "%s", buf);
                         free (buf);
                       }
                     __set_errno (oerrno);
                     perror(0);
                     ai = ai->ai_next;
                     getnameinfo(ai->ai_addr, ai->ai_addrlen,
                                paddr, sizeof(paddr),
                                NULL, 0,
                                NI_NUMERICHOST);
                     if (__asprintf (&buf, _("Trying %s...\n"), paddr) >= 0)
                       {
                         __fxprintf (NULL, "%s", buf);
                         free (buf);
                       }
                     continue;
              }
              if (refused && timo <= 16) {
                     (void)__sleep(timo);
                     timo *= 2;
                     ai = res;
                     refused = 0;
                     continue;
              }
              freeaddrinfo(res);
              (void)__fxprintf(NULL, "%s: %s\n", *ahost,
                             __strerror_r(errno, errbuf, sizeof (errbuf)));
              __sigsetmask(oldmask);
              return -1;
       }
       lport--;
       if (fd2p == 0) {
              __write(s, "", 1);
              lport = 0;
       } else {
              char num[8];
              int s2 = rresvport_af(&lport, ai->ai_family), s3;
              socklen_t len = ai->ai_addrlen;

              if (s2 < 0)
                     goto bad;
              __listen(s2, 1);
              (void)__snprintf(num, sizeof(num), "%d", lport);
              if (__write(s, num, strlen(num)+1) != (ssize_t)strlen(num)+1) {
                     char *buf = NULL;

                     if (__asprintf (&buf, _("\
rcmd: write (setting up stderr): %m\n")) >= 0)
                       {
                         __fxprintf(NULL, "%s", buf);
                         free (buf);
                       }
                     (void)__close(s2);
                     goto bad;
              }
              pfd[0].fd = s;
              pfd[1].fd = s2;
              __set_errno (0);
              if (__poll (pfd, 2, -1) < 1 || (pfd[1].revents & POLLIN) == 0){
                     char *buf = NULL;

                     if ((errno != 0
                          && __asprintf(&buf, _("\
rcmd: poll (setting up stderr): %m\n")) >= 0)
                         || (errno == 0
                            && __asprintf(&buf, _("\
poll: protocol failure in circuit setup\n")) >= 0))
                       {
                         __fxprintf (NULL, "%s", buf);
                         free  (buf);
                       }
                     (void)__close(s2);
                     goto bad;
              }
              s3 = TEMP_FAILURE_RETRY (accept(s2, (struct sockaddr *)&from,
                                          &len));
              switch (from.ss_family) {
              case AF_INET:
                     rport = ntohs(((struct sockaddr_in *)&from)->sin_port);
                     break;
              case AF_INET6:
                     rport = ntohs(((struct sockaddr_in6 *)&from)->sin6_port);
                     break;
              default:
                     rport = 0;
                     break;
              }
              (void)__close(s2);
              if (s3 < 0) {
                     (void)__fxprintf(NULL, "rcmd: accept: %m\n");
                     lport = 0;
                     goto bad;
              }
              *fd2p = s3;

              if (rport >= IPPORT_RESERVED || rport < IPPORT_RESERVED / 2){
                     char *buf = NULL;

                     if (__asprintf(&buf, _("\
socket: protocol failure in circuit setup\n")) >= 0)
                       {
                         __fxprintf (NULL, "%s", buf);
                         free (buf);
                       }
                     goto bad2;
              }
       }
       struct iovec iov[3] =
         {
           [0] = { .iov_base = (void *) locuser,
                  .iov_len = strlen (locuser) + 1 },
           [1] = { .iov_base = (void *) remuser,
                  .iov_len = strlen (remuser) + 1 },
           [2] = { .iov_base = (void *) cmd,
                  .iov_len = strlen (cmd) + 1 }
         };
       (void) TEMP_FAILURE_RETRY (__writev (s, iov, 3));
       n = TEMP_FAILURE_RETRY (__read(s, &c, 1));
       if (n != 1) {
              char *buf = NULL;

              if ((n == 0
                   && __asprintf(&buf, _("rcmd: %s: short read"),
                               *ahost) >= 0)
                  || (n != 0
                     && __asprintf(&buf, "rcmd: %s: %m\n", *ahost) >= 0))
                {
                  __fxprintf (NULL, "%s", buf);
                  free (buf);
                }
              goto bad2;
       }
       if (c != 0) {
              while (__read(s, &c, 1) == 1) {
                     (void)__write(STDERR_FILENO, &c, 1);
                     if (c == '\n')
                            break;
              }
              goto bad2;
       }
       __sigsetmask(oldmask);
       freeaddrinfo(res);
       return s;
bad2:
       if (lport)
              (void)__close(*fd2p);
bad:
       (void)__close(s);
       __sigsetmask(oldmask);
       freeaddrinfo(res);
       return -1;
}

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int rresvport_af ( int alport,
sa_family_t  family 
)

Definition at line 368 of file rcmd.c.

{
       struct sockaddr_storage ss;
       int s;
       size_t len;
       uint16_t *sport;

       switch(family){
       case AF_INET:
              len = sizeof(struct sockaddr_in);
              sport = &((struct sockaddr_in *)&ss)->sin_port;
              break;
       case AF_INET6:
              len = sizeof(struct sockaddr_in6);
              sport = &((struct sockaddr_in6 *)&ss)->sin6_port;
              break;
       default:
              __set_errno (EAFNOSUPPORT);
              return -1;
       }
       s = __socket(family, SOCK_STREAM, 0);
       if (s < 0)
              return -1;

       memset (&ss, '\0', sizeof(ss));
#ifdef SALEN
       ss.__ss_len = len;
#endif
       ss.ss_family = family;

       /* Ignore invalid values.  */
       if (*alport < IPPORT_RESERVED / 2)
              *alport = IPPORT_RESERVED / 2;
       else if (*alport >= IPPORT_RESERVED)
              *alport = IPPORT_RESERVED - 1;

       int start = *alport;
       do {
              *sport = htons((uint16_t) *alport);
              if (__bind(s, (struct sockaddr *)&ss, len) >= 0)
                     return s;
              if (errno != EADDRINUSE) {
                     (void)__close(s);
                     return -1;
              }
              if ((*alport)-- == IPPORT_RESERVED/2)
                     *alport = IPPORT_RESERVED - 1;
       } while (*alport != start);
       (void)__close(s);
       __set_errno (EAGAIN);
       return -1;
}

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static int ruserok2_sa ( struct sockaddr ra,
size_t  ralen,
int  superuser,
const char *  ruser,
const char *  luser,
const char *  rhost 
) [static]

Definition at line 524 of file rcmd.c.

{
  FILE *hostf = NULL;
  int isbad = -1;

  if (!superuser)
    hostf = iruserfopen (_PATH_HEQUIV, 0);

  if (hostf)
    {
      isbad = __validuser2_sa (hostf, ra, ralen, luser, ruser, rhost);
      fclose (hostf);

      if (!isbad)
       return 0;
    }

  if (__check_rhosts_file || superuser)
    {
      char *pbuf;
      struct passwd pwdbuf, *pwd;
      size_t dirlen;
      size_t buflen = __sysconf (_SC_GETPW_R_SIZE_MAX);
      char *buffer = __alloca (buflen);
      uid_t uid;

      if (__getpwnam_r (luser, &pwdbuf, buffer, buflen, &pwd) != 0
         || pwd == NULL)
       return -1;

      dirlen = strlen (pwd->pw_dir);
      pbuf = alloca (dirlen + sizeof "/.rhosts");
      __mempcpy (__mempcpy (pbuf, pwd->pw_dir, dirlen),
               "/.rhosts", sizeof "/.rhosts");

       /* Change effective uid while reading .rhosts.  If root and
         reading an NFS mounted file system, can't read files that
         are protected read/write owner only.  */
       uid = __geteuid ();
       seteuid (pwd->pw_uid);
       hostf = iruserfopen (pbuf, pwd->pw_uid);

       if (hostf != NULL)
        {
           isbad = __validuser2_sa (hostf, ra, ralen, luser, ruser, rhost);
           fclose (hostf);
        }

       seteuid (uid);
       return isbad;
    }
  return -1;
}

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int ruserok_af ( char *  rhost,
int  superuser,
char *  ruser,
char *  luser,
sa_family_t  af 
) const

Definition at line 435 of file rcmd.c.

{
       struct addrinfo hints, *res, *res0;
       int gai;
       int ret;

       memset (&hints, '\0', sizeof(hints));
       hints.ai_family = af;
       gai = getaddrinfo(rhost, NULL, &hints, &res0);
       if (gai)
              return -1;
       ret = -1;
       for (res=res0; res; res=res->ai_next)
              if (ruserok2_sa(res->ai_addr, res->ai_addrlen,
                            superuser, ruser, luser, rhost) == 0){
                     ret = 0;
                     break;
              }
       freeaddrinfo(res0);
       return (ret);
}

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static int ruserok_sa ( struct sockaddr ra,
size_t  ralen,
int  superuser,
const char *  ruser,
const char *  luser 
) [static]

Definition at line 585 of file rcmd.c.

{
  return ruserok2_sa(ra, ralen, superuser, ruser, luser, "-");
}

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Variable Documentation

Definition at line 431 of file rcmd.c.

Definition at line 432 of file rcmd.c.