rexec.c 5.9 KB

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  1. /*
  2. * Copyright (c) 1980, 1993
  3. * The Regents of the University of California. All rights reserved.
  4. *
  5. * Redistribution and use in source and binary forms, with or without
  6. * modification, are permitted provided that the following conditions
  7. * are met:
  8. * 1. Redistributions of source code must retain the above copyright
  9. * notice, this list of conditions and the following disclaimer.
  10. * 2. Redistributions in binary form must reproduce the above copyright
  11. * notice, this list of conditions and the following disclaimer in the
  12. * documentation and/or other materials provided with the distribution.
  13. * 4. Neither the name of the University nor the names of its contributors
  14. * may be used to endorse or promote products derived from this software
  15. * without specific prior written permission.
  16. *
  17. * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18. * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19. * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20. * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21. * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22. * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23. * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24. * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25. * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26. * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27. * SUCH DAMAGE.
  28. */
  29. #define __FORCE_GLIBC
  30. #include <features.h>
  31. #include <sys/types.h>
  32. #include <sys/socket.h>
  33. #include <netinet/in.h>
  34. #include <alloca.h>
  35. #include <stdio.h>
  36. #include <netdb.h>
  37. #include <errno.h>
  38. #include <stdlib.h>
  39. #include <string.h>
  40. #include <unistd.h>
  41. /* Experimentally off - libc_hidden_proto(memset) */
  42. /* Experimentally off - libc_hidden_proto(strlen) */
  43. /* Experimentally off - libc_hidden_proto(strncpy) */
  44. /* libc_hidden_proto(read) */
  45. /* libc_hidden_proto(write) */
  46. /* libc_hidden_proto(close) */
  47. /* libc_hidden_proto(socket) */
  48. /* libc_hidden_proto(perror) */
  49. /* libc_hidden_proto(sprintf) */
  50. /* libc_hidden_proto(snprintf) */
  51. /* libc_hidden_proto(getsockname) */
  52. /* libc_hidden_proto(getnameinfo) */
  53. /* libc_hidden_proto(getaddrinfo) */
  54. /* libc_hidden_proto(freeaddrinfo) */
  55. /* libc_hidden_proto(sleep) */
  56. /* libc_hidden_proto(atoi) */
  57. /* libc_hidden_proto(connect) */
  58. /* libc_hidden_proto(accept) */
  59. /* libc_hidden_proto(listen) */
  60. /* libc_hidden_proto(ruserpass) */
  61. #define SA_LEN(_x) __libc_sa_len((_x)->sa_family)
  62. extern int __libc_sa_len (sa_family_t __af) __THROW attribute_hidden;
  63. /* int rexecoptions; - google does not know it */
  64. static char ahostbuf[NI_MAXHOST];
  65. /* libc_hidden_proto(rexec_af) */
  66. int
  67. rexec_af(char **ahost, int rport, const char *name, const char *pass, const char *cmd, int *fd2p, sa_family_t af)
  68. {
  69. struct sockaddr_storage sa2, from;
  70. struct addrinfo hints, *res0;
  71. const char *orig_name = name;
  72. const char *orig_pass = pass;
  73. u_short port = 0;
  74. int s, timo = 1, s3;
  75. char c;
  76. int gai;
  77. char servbuff[NI_MAXSERV];
  78. if (sizeof(servbuff) < sizeof(int)*3 + 2) {
  79. snprintf(servbuff, sizeof(servbuff), "%d", ntohs(rport));
  80. servbuff[sizeof(servbuff) - 1] = '\0';
  81. } else {
  82. sprintf(servbuff, "%d", ntohs(rport));
  83. }
  84. memset(&hints, '\0', sizeof(hints));
  85. hints.ai_family = af;
  86. hints.ai_socktype = SOCK_STREAM;
  87. hints.ai_flags = AI_CANONNAME;
  88. gai = getaddrinfo(*ahost, servbuff, &hints, &res0);
  89. if (gai){
  90. /* XXX: set errno? */
  91. return -1;
  92. }
  93. if (res0->ai_canonname){
  94. strncpy(ahostbuf, res0->ai_canonname, sizeof(ahostbuf));
  95. ahostbuf[sizeof(ahostbuf)-1] = '\0';
  96. *ahost = ahostbuf;
  97. }
  98. else{
  99. *ahost = NULL;
  100. __set_errno (ENOENT);
  101. return -1;
  102. }
  103. ruserpass(res0->ai_canonname, &name, &pass);
  104. retry:
  105. s = socket(res0->ai_family, res0->ai_socktype, 0);
  106. if (s < 0) {
  107. perror("rexec: socket");
  108. return (-1);
  109. }
  110. if (connect(s, res0->ai_addr, res0->ai_addrlen) < 0) {
  111. if (errno == ECONNREFUSED && timo <= 16) {
  112. (void) close(s);
  113. sleep(timo);
  114. timo *= 2;
  115. goto retry;
  116. }
  117. perror(res0->ai_canonname);
  118. return (-1);
  119. }
  120. if (fd2p == 0) {
  121. (void) write(s, "", 1);
  122. port = 0;
  123. } else {
  124. char num[32];
  125. int s2;
  126. socklen_t sa2len;
  127. s2 = socket(res0->ai_family, res0->ai_socktype, 0);
  128. if (s2 < 0) {
  129. (void) close(s);
  130. return (-1);
  131. }
  132. listen(s2, 1);
  133. sa2len = sizeof (sa2);
  134. if (getsockname(s2, (struct sockaddr *)&sa2, &sa2len) < 0) {
  135. perror("getsockname");
  136. (void) close(s2);
  137. goto bad;
  138. } else if (sa2len != SA_LEN((struct sockaddr *)&sa2)) {
  139. __set_errno(EINVAL);
  140. (void) close(s2);
  141. goto bad;
  142. }
  143. port = 0;
  144. if (!getnameinfo((struct sockaddr *)&sa2, sa2len,
  145. NULL, 0, servbuff, sizeof(servbuff),
  146. NI_NUMERICSERV))
  147. port = atoi(servbuff);
  148. (void) sprintf(num, "%u", port);
  149. (void) write(s, num, strlen(num)+1);
  150. { socklen_t len = sizeof (from);
  151. s3 = TEMP_FAILURE_RETRY (accept(s2, (struct sockaddr *)&from,
  152. &len));
  153. close(s2);
  154. if (s3 < 0) {
  155. perror("accept");
  156. port = 0;
  157. goto bad;
  158. }
  159. }
  160. *fd2p = s3;
  161. }
  162. (void) write(s, name, strlen(name) + 1);
  163. /* should public key encypt the password here */
  164. (void) write(s, pass, strlen(pass) + 1);
  165. (void) write(s, cmd, strlen(cmd) + 1);
  166. /* We don't need the memory allocated for the name and the password
  167. in ruserpass anymore. */
  168. if (name != orig_name)
  169. free ((char *) name);
  170. if (pass != orig_pass)
  171. free ((char *) pass);
  172. if (read(s, &c, 1) != 1) {
  173. perror(*ahost);
  174. goto bad;
  175. }
  176. if (c != 0) {
  177. while (read(s, &c, 1) == 1) {
  178. (void) write(2, &c, 1);
  179. if (c == '\n')
  180. break;
  181. }
  182. goto bad;
  183. }
  184. freeaddrinfo(res0);
  185. return (s);
  186. bad:
  187. if (port)
  188. (void) close(*fd2p);
  189. (void) close(s);
  190. freeaddrinfo(res0);
  191. return (-1);
  192. }
  193. libc_hidden_def(rexec_af)
  194. int
  195. rexec(ahost, rport, name, pass, cmd, fd2p)
  196. char **ahost;
  197. int rport;
  198. const char *name, *pass, *cmd;
  199. int *fd2p;
  200. {
  201. return rexec_af(ahost, rport, name, pass, cmd, fd2p, AF_INET);
  202. }