diff options
Diffstat (limited to 'newlib/libc/sys/linux/net/rcmdsh.c')
| -rw-r--r-- | newlib/libc/sys/linux/net/rcmdsh.c | 169 |
1 files changed, 169 insertions, 0 deletions
diff --git a/newlib/libc/sys/linux/net/rcmdsh.c b/newlib/libc/sys/linux/net/rcmdsh.c new file mode 100644 index 000000000..741814c11 --- /dev/null +++ b/newlib/libc/sys/linux/net/rcmdsh.c @@ -0,0 +1,169 @@ +/* $OpenBSD: rcmdsh.c,v 1.5 1998/04/25 16:23:58 millert 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>. + */ + +#include <sys/cdefs.h> +#include <sys/types.h> +#include <machine/endian.h> + +#include <sys/types.h> +#include <sys/socket.h> +#include <sys/wait.h> + +#include <errno.h> +#include <netdb.h> +#include <paths.h> +#include <pwd.h> +#include <stdio.h> +#include <string.h> +#include <unistd.h> + +#ifndef _PATH_RSH +#define _PATH_RSH "/usr/bin/rsh" +#endif + +/* + * 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. + */ +int +rcmdsh(ahost, rport, locuser, remuser, cmd, rshprog) + char **ahost; + int rport; + const char *locuser, *remuser, *cmd, *rshprog; +{ + struct addrinfo hints, *res; + int cpid, sp[2], error; + char *p; + struct passwd *pw; + char num[8]; + static char hbuf[NI_MAXHOST]; + + /* 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) { + memset(&hints, 0, sizeof(hints)); + hints.ai_flags = AI_CANONNAME; + hints.ai_family = PF_UNSPEC; + hints.ai_socktype = SOCK_STREAM; + (void)snprintf(num, sizeof(num), "%d", ntohs(rport)); + error = getaddrinfo(*ahost, num, &hints, &res); + if (error) { + fprintf(stderr, "rcmdsh: getaddrinfo: %s\n", + gai_strerror(error)); + return (-1); + } + if (res->ai_canonname) { + strncpy(hbuf, res->ai_canonname, sizeof(hbuf) - 1); + hbuf[sizeof(hbuf) - 1] = '\0'; + *ahost = hbuf; + } + freeaddrinfo(res); + } + + /* Get a socketpair we'll use for stdin and stdout. */ + if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, sp) == -1) { + perror("rcmdsh: socketpair"); + return (-1); + } + + cpid = fork(); + if (cpid == -1) { + 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) == -1 || dup2(0, 1) == -1) { + perror("rcmdsh: dup2 failed"); + _exit(255); + } + /* Fork again to lose parent. */ + cpid = fork(); + if (cpid == -1) { + 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) == -1) { + (void)fprintf(stderr, "rcmdsh: setuid(%u): %s\n", + pw->pw_uid, strerror(errno)); + _exit(255); + } + + /* + * If remote host is "localhost" and local and remote users + * are the same, avoid running remote shell for efficiency. + */ + if (strcmp(*ahost, "localhost") == 0 && + strcmp(locuser, remuser) == 0) { + if (pw->pw_shell[0] == '\0') + rshprog = _PATH_BSHELL; + else + rshprog = pw->pw_shell; + p = strrchr(rshprog, '/'); + execlp(rshprog, p ? p + 1 : rshprog, "-c", cmd, + (char *)NULL); + } else { + p = strrchr(rshprog, '/'); + execlp(rshprog, p ? p + 1 : rshprog, *ahost, "-l", + remuser, cmd, (char *)NULL); + } + (void)fprintf(stderr, "rcmdsh: execlp %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 */ +} |