sys/src/ape/lib/bsd/rcmd.c

   1 /* posix */
   2 #include <sys/types.h>
   3 #include <unistd.h>
   4 #include <stdlib.h>
   5 #include <stdio.h>
   6 #include <string.h>
   7 #include <errno.h>
   8 #include <signal.h>
   9
  10 /* socket extensions */
  11 #include <sys/socket.h>
  12 #include <netinet/in.h>
  13 #include <sys/un.h>
  14 #include <netdb.h>
  15
  16 #include "priv.h"
  17
  18 static char pbotch[] = "rcmd: protocol botch\n";
  19 static char lbotch[] = "rcmd: botch starting error stream\n";
  20
  21 static void
  22 ding(int x)
  23 {
  24 }
  25
  26 int
  27 rcmd(char **dst, int port, char *luser, char *ruser, char *cmd, int *fd2p)
  28 {
  29         char c;
  30         int i, fd, lfd, fd2, port2;
  31         struct hostent *h;
  32         Rock *r;
  33         struct sockaddr_in in;
  34         char buf[128];
  35         void    (*x)(int);
  36
  37         h = gethostbyname(*dst);
  38         if(h == 0)
  39                 return -1;
  40         *dst = h->h_name;
  41
  42         /* connect using a reserved tcp port */
  43         fd = socket(PF_INET, SOCK_STREAM, 0);
  44         if(fd < 0)
  45                 return -1;
  46         r = _sock_findrock(fd, 0);
  47         if(r == 0){
  48                 errno = ENOTSOCK;
  49                 return -1;
  50         }
  51         r->reserved = 1;
  52         in.sin_family = AF_INET;
  53         in.sin_port = htons(port);
  54         memmove(&in.sin_addr, h->h_addr_list[0], sizeof(in.sin_addr));
  55         if(connect(fd, &in, sizeof(in)) < 0){
  56                 close(fd);
  57                 return -1;
  58         }
  59
  60         /* error stream */
  61         if(fd2p){
  62                 /* create an error stream and wait for a call in */
  63                 for(i = 0; i < 10; i++){
  64                         lfd = rresvport(&port2);
  65                         if(lfd < 0)
  66                                 continue;
  67                         if(listen(lfd, 1) == 0)
  68                                 break;
  69                         close(lfd);
  70                 }
  71                 if(i >= 10){
  72                         fprintf(stderr, pbotch);
  73                         return -1;
  74                 }
  75
  76                 snprintf(buf, sizeof buf, "%d", port2);
  77                 if(write(fd, buf, strlen(buf)+1) < 0){
  78                         close(fd);
  79                         close(lfd);
  80                         fprintf(stderr, lbotch);
  81                         return -1;
  82                 }
  83         } else {
  84                 if(write(fd, "", 1) < 0){
  85                         fprintf(stderr, pbotch);
  86                         return -1;
  87                 }
  88         }
  89
  90         /* pass id's and command */
  91         if(write(fd, luser, strlen(luser)+1) < 0
  92         || write(fd, ruser, strlen(ruser)+1) < 0
  93         || write(fd, cmd, strlen(cmd)+1) < 0){
  94                 if(fd2p)
  95                         close(fd2);
  96                 fprintf(stderr, pbotch);
  97                 return -1;
  98         }
  99
 100         if(fd2p){
 101                 x = signal(SIGALRM, ding);
 102                 alarm(15);
 103                 fd2 = accept(lfd, &in, &i);
 104                 alarm(0);
 105                 close(lfd);
 106                 signal(SIGALRM, x);
 107
 108                 if(fd2 < 0){
 109                         close(fd);
 110                         close(lfd);
 111                         fprintf(stderr, lbotch);
 112                         return -1;
 113                 }
 114                 *fd2p = fd2;
 115         }
 116
 117         /* get reply */
 118         if(read(fd, &c, 1) != 1){
 119                 if(fd2p)
 120                         close(fd2);
 121                 fprintf(stderr, pbotch);
 122                 return -1;
 123         }
 124         if(c == 0)
 125                 return fd;
 126         i = 0;
 127         while(c){
 128                 buf[i++] = c;
 129                 if(read(fd, &c, 1) != 1)
 130                         break;
 131                 if(i >= sizeof(buf)-1)
 132                         break;
 133         }
 134         buf[i] = 0;
 135         fprintf(stderr, "rcmd: %s\n", buf);
 136         close(fd);
 137         return -1;
 138 }