src/slave.c

   1 #define _XOPEN_SOURCE
   2 #define _GNU_SOURCE
   3
   4 //#define _SIMPLE_SLAVE
   5
   6 #include "slave.h"
   7 #include <assert.h>
   8
   9 #include "network.h"
  10 #include "daemon.h"
  11 #include "log.h"
  12 #include <errno.h>
  13 #include <pty.h>
  14 #include <fcntl.h>
  15
  16 #include <pthread.h>
  17 #include <syslog.h>
  18 #include <signal.h>
  19 #include <unistd.h>
  20 #include <sys/types.h>
  21 #include <sys/wait.h>
  22 #include <sys/socket.h>
  23 #include <netinet/tcp.h>
  24
  25
  26
  27 Slave * slave;
  28
  29
  30 int running;
  31
  32 void Slave_main(Options * o)
  33 {
  34
  35         if (fork() != 0)
  36                 exit(EXIT_SUCCESS);
  37
  38
  39         o->verbosity = 100;
  40         freopen(SLAVE_LOGFILE, "w", stderr);
  41         setbuf(stderr, NULL);
  42         slave = (Slave*)(calloc(o->nCPU, sizeof(Slave)));
  43
  44         int net_fd = -1;
  45         if (o->encrypt)
  46                 net_fd = Network_client("localhost", o->port,100);
  47         else
  48                 net_fd = Network_client(o->master_addr, o->port,100);
  49
  50         FILE * f = fdopen(net_fd, "w"); setbuf(f, NULL);
  51         fprintf(f, "%d\n", o->nCPU);
  52
  53         log_print(2, "Slave_main", "Waiting on bell from master");
  54         char c;
  55         if (read(net_fd, &c, sizeof(char)) == 0 || c != '\a')
  56                 error("Slave_main", "Didn't get bell from master");
  57
  58
  59
  60
  61         log_print(2, "Slave_main", "Got bell from master");
  62         running = o->nCPU;
  63         for (int i = 0; i < o->nCPU; ++i)
  64         {
  65                 int new_fd = net_fd;
  66                 if (i != o->nCPU-1)
  67                 {
  68
  69
  70                         if (read(net_fd, &c, sizeof(char)) == 0 || c != '\a')
  71                                 error("Slave_main", "Didn't get bell from master authorising connection of slave %d", i);
  72                         sleep(1);
  73
  74                         log_print(3, "Slave_main", "Connecting slave %d to port %d at time %d", i, o->port+i+1, time(NULL));
  75                         if (o->encrypt)
  76                                 new_fd = Network_client("localhost", o->port+i+1, 100);
  77                         else
  78                                 new_fd = Network_client(o->master_addr, o->port+i+1, 100);
  79
  80
  81
  82                 }
  83
  84                 slave[i].in = new_fd; slave[i].out = new_fd;
  85
  86                 slave[i].pid = fork();
  87                 if (slave[i].pid == 0)
  88                 {
  89                         dup2(slave[i].in, fileno(stdin));
  90                         dup2(slave[i].out, fileno(stdout));
  91                         execlp(o->shell, o->shell, NULL);
  92                 }
  93         }
  94
  95         Slave_loop(o);
  96
  97         free(slave);
  98         exit(EXIT_SUCCESS);
  99 }
 100
 101 void Slave_loop(Options * o)
 102 {
 103
 104         int p = -1; int s = 0;
 105
 106         while (running > 0)
 107         {
 108                 p = waitpid(-1, &s, 0);
 109                 if (p == -1)
 110                 {
 111                         log_print(0, "Slave_loop", "waitpid : %s", strerror(errno));
 112                         continue;
 113                 }
 114                 if (s != SHELL_EXIT_CODE)
 115                 {
 116                         // there was an error
 117
 118                         int i = 0;
 119                         for (i = 0; i < o->nCPU; ++i)
 120                         {
 121                                 if (slave[i].pid == p) break;
 122                         }
 123                         if (i >= o->nCPU)
 124                                 error("Slave_loop", "No child matches pid %d", p);
 125
 126                         log_print(0, "Slave_loop", "Child [%d] exits with status %d; restarting", p, s);
 127                         slave[i].pid = fork();
 128                         if (slave[i].pid == 0)
 129                         {
 130                                 dup2(slave[i].in, fileno(stdin));
 131                                 dup2(slave[i].out, fileno(stdout));
 132                                 execlp(o->shell, o->shell, NULL);
 133                         }
 134
 135                         char buffer[] = "\f\a\a\a";
 136                         if (write(slave[i].in, buffer, strlen(buffer)) <= 0)
 137                                 log_print(0, "Slave_loop", "Slave %d input closed", i);
 138                 }
 139                 else
 140                         --running;
 141         }
 142 }