1 files changed, 193 insertions, 0 deletions

diff --git a/src/lib/libc/net/rcmdsh.c b/src/lib/libc/net/rcmdsh.c
new file mode 100644
index 0000000000..3ec97e4763
--- /dev/null
+++ b/src/lib/libc/net/rcmdsh.c
@@ -0,0 +1,193 @@
+/*      $OpenBSD: rcmdsh.c,v 1.9 2004/04/01 04:14:29 marc Exp $ */ 
+
+/*
+ * Copyright (c) 2001, MagniComp
+ * All rights reserved.
+ * 
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright 
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright 
+ *    notice, this list of conditions and the following disclaimer in 
+ *    the documentation and/or other materials provided with the distribution. 
+ * 3. Neither the name of the MagniComp nor the names of its contributors may
+ *    be used to endorse or promote products derived from this software
+ *    without specific prior written permission. 
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
+ * USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/*
+ * This is an rcmd() replacement originally by 
+ * Chris Siebenmann <cks@utcc.utoronto.ca>.
+ */
+
+#if defined(LIBC_SCCS) && !defined(lint)
+static char *rcsid = "$OpenBSD: rcmdsh.c,v 1.9 2004/04/01 04:14:29 marc Exp $";
+#endif /* LIBC_SCCS and not lint */
+
+#include      <sys/types.h>
+#include      <sys/socket.h>
+#include      <sys/wait.h>
+#include      <signal.h>
+#include      <errno.h>
+#include      <netdb.h>
+#include      <stdio.h>
+#include      <stdlib.h>
+#include      <string.h>
+#include      <pwd.h>
+#include      <paths.h>
+#include      <unistd.h>
+
+/*
+ * This is a replacement rcmd() function that uses the rsh(1)
+ * program in place of a direct rcmd(3) function call so as to
+ * avoid having to be root.  Note that rport is ignored.
+ */
+/* ARGSUSED */
+int
+rcmdsh(ahost, rport, locuser, remuser, cmd, rshprog)
+        char **ahost;
+        int rport;
+        const char *locuser, *remuser, *cmd;
+        char *rshprog;
+{
+        struct hostent *hp;
+        int sp[2];
+        pid_t cpid;
+        char *p;
+        struct passwd *pw;
+
+        /* What rsh/shell to use. */
+        if (rshprog == NULL)
+                rshprog = _PATH_RSH;
+
+        /* locuser must exist on this host. */
+        if ((pw = getpwnam(locuser)) == NULL) {
+                (void) fprintf(stderr, "rcmdsh: unknown user: %s\n", locuser);
+                return(-1);
+        }
+
+        /* Validate remote hostname. */
+        if (strcmp(*ahost, "localhost") != 0) {
+                if (((hp = gethostbyname2(*ahost, AF_INET)) == NULL) &&
+                    ((hp = gethostbyname2(*ahost, AF_INET6)) == NULL)) {
+                        herror(*ahost);
+                        return(-1);
+                }
+                *ahost = hp->h_name;
+        }
+
+        /* Get a socketpair we'll use for stdin and stdout. */
+        if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, sp) < 0) {
+                perror("rcmdsh: socketpair");
+                return(-1);
+        }
+
+        cpid = fork();
+        if (cpid < 0) {
+                perror("rcmdsh: fork failed");
+                return(-1);
+        } else if (cpid == 0) {
+                /*
+                 * Child.  We use sp[1] to be stdin/stdout, and close sp[0].
+                 */
+                (void) close(sp[0]);
+                if (dup2(sp[1], 0) < 0 || dup2(0, 1) < 0) {
+                        perror("rcmdsh: dup2 failed");
+                        _exit(255);
+                }
+                /* Fork again to lose parent. */
+                cpid = fork();
+                if (cpid < 0) {
+                        perror("rcmdsh: fork to lose parent failed");
+                        _exit(255);
+                }
+                if (cpid > 0)
+                        _exit(0);
+
+                /* In grandchild here.  Become local user for rshprog. */
+                if (setuid(pw->pw_uid)) {
+                        (void) fprintf(stderr, "rcmdsh: setuid(%u): %s\n",
+                                       pw->pw_uid, strerror(errno));
+                        _exit(255);
+                }
+
+                /*
+                 * If remote host is "localhost" and local and remote user
+                 * are the same, avoid running remote shell for efficiency.
+                 */
+                if (!strcmp(*ahost, "localhost") && !strcmp(locuser, remuser)) {
+                        char *argv[4];
+                        if (pw->pw_shell[0] == '\0')
+                                rshprog = _PATH_BSHELL;
+                        else
+                                rshprog = pw->pw_shell;
+                        p = strrchr(rshprog, '/');
+                        argv[0] = p ? p + 1 : rshprog;
+                        argv[1] = "-c";
+                        argv[2] = (char *)cmd;
+                        argv[3] = NULL;
+                        execvp(rshprog, argv);
+                } else if ((p = strchr(rshprog, ' ')) == NULL) {
+                        /* simple case */
+                        char *argv[6];
+                        p = strrchr(rshprog, '/');
+                        argv[0] = p ? p + 1 : rshprog;
+                        argv[1] = "-l";
+                        argv[2] = (char *)remuser;
+                        argv[3] = *ahost;
+                        argv[4] = (char *)cmd;
+                        argv[5] = NULL;
+                        execvp(rshprog, argv);
+                } else {
+                        /* must pull args out of rshprog and dyn alloc argv */
+                        char **argv, **ap;
+                        int n;
+                        for (n = 7; (p = strchr(++p, ' ')) != NULL; n++)
+                                continue;
+                        rshprog = strdup(rshprog);
+                        ap = argv = malloc(sizeof(char *) * n);
+                        if (rshprog == NULL || argv == NULL) {
+                                perror("rcmdsh");
+                                _exit(255);
+                        }
+                        while ((p = strsep(&rshprog, " ")) != NULL) {
+                                if (*p == '\0')
+                                        continue;
+                                *ap++ = p;
+                        }
+                        if (ap != argv)         /* all spaces?!? */
+                                rshprog = argv[0];
+                        if ((p = strrchr(argv[0], '/')) != NULL)
+                                argv[0] = p + 1;
+                        *ap++ = "-l";
+                        *ap++ = (char *)remuser;
+                        *ap++ = *ahost;
+                        *ap++ = (char *)cmd;
+                        *ap++ = NULL;
+                        execvp(rshprog, argv);
+                }
+                (void) fprintf(stderr, "rcmdsh: execvp %s failed: %s\n",
+                               rshprog, strerror(errno));
+                _exit(255);
+        } else {
+                /* Parent. close sp[1], return sp[0]. */
+                (void) close(sp[1]);
+                /* Reap child. */
+                (void) wait(NULL);
+                return(sp[0]);
+        }
+        /* NOTREACHED */
+}