rx.c 3.0 KB

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  1. #include <u.h>
  2. #include <libc.h>
  3. #include <auth.h>
  4. int eof; /* send an eof if true */
  5. char *note = "die: yankee dog";
  6. char *ruser;
  7. void rex(int, char*);
  8. void tcpexec(int, char*, char*);
  9. int call(char *, char*, char*, char**);
  10. char *buildargs(char*[]);
  11. int send(int);
  12. void error(char*, char*);
  13. void
  14. usage(void)
  15. {
  16. fprint(2, "usage: %s [-e] net!host command...\n", argv0);
  17. exits("usage");
  18. }
  19. void
  20. main(int argc, char *argv[])
  21. {
  22. char *host, *addr, *args;
  23. int fd;
  24. eof = 1;
  25. ARGBEGIN{
  26. case 'e':
  27. eof = 0;
  28. break;
  29. case 'l':
  30. ruser = ARGF();
  31. break;
  32. default:
  33. usage();
  34. }ARGEND
  35. if(argc < 2)
  36. usage();
  37. host = argv[0];
  38. args = buildargs(&argv[1]);
  39. /* specific attempts */
  40. fd = call("tcp", host, "shell", &addr);
  41. if(fd >= 0)
  42. tcpexec(fd, addr, args);
  43. /* generic attempts */
  44. fd = call(0, host, "rexexec", &addr);
  45. if(fd >= 0)
  46. rex(fd, args);
  47. error("can't dial", host);
  48. exits(0);
  49. }
  50. int
  51. call(char *net, char *host, char *service, char **na)
  52. {
  53. *na = netmkaddr(host, net, service);
  54. return dial(*na, 0, 0, 0);
  55. }
  56. void
  57. rex(int fd, char *cmd)
  58. {
  59. char buf[4096];
  60. int kid, n;
  61. AuthInfo *ai;
  62. ai = auth_proxy(fd, auth_getkey, "proto=p9any role=client");
  63. if(ai == nil)
  64. error("auth_proxy", nil);
  65. write(fd, cmd, strlen(cmd)+1);
  66. kid = send(fd);
  67. while((n=read(fd, buf, sizeof buf))>0)
  68. if(write(1, buf, n)!=n)
  69. error("write error", 0);
  70. sleep(250);
  71. postnote(PNPROC, kid, note);/**/
  72. exits(0);
  73. }
  74. void
  75. tcpexec(int fd, char *addr, char *cmd)
  76. {
  77. char *u, buf[4096];
  78. int kid, n;
  79. char *r;
  80. /*
  81. * do the ucb authentication and send command
  82. */
  83. u = getuser();
  84. r = ruser ? ruser : u;
  85. if(write(fd, "", 1)<0 || write(fd, u, strlen(u)+1)<0
  86. || write(fd, r, strlen(r)+1)<0 || write(fd, cmd, strlen(cmd)+1)<0){
  87. close(fd);
  88. error("can't authenticate to", addr);
  89. }
  90. /*
  91. * get authentication reply
  92. */
  93. if(read(fd, buf, 1) != 1){
  94. close(fd);
  95. error("can't authenticate to", addr);
  96. }
  97. if(buf[0] != 0){
  98. while(read(fd, buf, 1) == 1){
  99. write(2, buf, 1);
  100. if(buf[0] == '\n')
  101. break;
  102. }
  103. close(fd);
  104. error("rejected by", addr);
  105. }
  106. kid = send(fd);
  107. while((n=read(fd, buf, sizeof buf))>0)
  108. if(write(1, buf, n)!=n)
  109. error("write error", 0);
  110. sleep(250);
  111. postnote(PNPROC, kid, note);/**/
  112. exits(0);
  113. }
  114. int
  115. send(int fd)
  116. {
  117. char buf[4096];
  118. int n;
  119. int kid;
  120. switch(kid = fork()){
  121. case -1:
  122. error("fork error", 0);
  123. case 0:
  124. break;
  125. default:
  126. return kid;
  127. }
  128. while((n=read(0, buf, sizeof buf))>0)
  129. if(write(fd, buf, n)!=n)
  130. exits("write error");
  131. if(eof)
  132. write(fd, buf, 0);
  133. exits(0);
  134. return 0; /* to keep compiler happy */
  135. }
  136. void
  137. error(char *s, char *z)
  138. {
  139. if(z == 0)
  140. fprint(2, "%s: %s: %r\n", argv0, s);
  141. else
  142. fprint(2, "%s: %s %s: %r\n", argv0, s, z);
  143. exits(s);
  144. }
  145. char *
  146. buildargs(char *argv[])
  147. {
  148. char *args;
  149. int m, n;
  150. args = malloc(1);
  151. args[0] = '\0';
  152. n = 0;
  153. while(*argv){
  154. m = strlen(*argv) + 1;
  155. args = realloc(args, n+m +1);
  156. if(args == 0)
  157. error("malloc fail", 0);
  158. args[n] = ' '; /* smashes old null */
  159. strcpy(args+n+1, *argv);
  160. n += m;
  161. argv++;
  162. }
  163. return args;
  164. }