apps/init/init.c

   1 /*
   2     meinOS - A unix-like x86 microkernel operating system
   3     Copyright (C) 2008  Janosch Gräf <janosch.graef@gmx.net>
   4
   5     This program is free software: you can redistribute it and/or modify
   6     it under the terms of the GNU General Public License as published by
   7     the Free Software Foundation, either version 3 of the License, or
   8     (at your option) any later version.
   9
  10     This program is distributed in the hope that it will be useful,
  11     but WITHOUT ANY WARRANTY; without even the implied warranty of
  12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13     GNU General Public License for more details.
  14
  15     You should have received a copy of the GNU General Public License
  16     along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17 */
  18
  19 #include <sys/types.h>
  20 #include <sys/stat.h>
  21 #include <limits.h>
  22 #include <signal.h>
  23 #include <stdio.h>
  24 #include <misc.h>
  25 #include <unistd.h>
  26 #include <proc.h>
  27 #include <rpc.h>
  28 #include <libgen.h>
  29
  30 #include "exe_elf.h"
  31 #include "init.conf.h"
  32
  33 static int sigusr1_count;
  34
  35 /**
  36  * SIGUSR1 Handler. Is called when process finishs initialzation
  37  *  @param sig Signal. MUST be SIGUSR1
  38  */
  39 static void sigusr1_handler(int sig) {
  40   sigusr1_count++;
  41 }
  42
  43 /**
  44  * Initializes Initialization ;)
  45  */
  46 static void init_init() {
  47   signal(SIGUSR1,sigusr1_handler);
  48 }
  49
  50 /**
  51  * Runs a program (Sends SIGCONT)
  52  *  @param name Name of program to run
  53  */
  54 static void init_run(const char *name) {
  55   pid_t pid = getpidbyname(name);
  56   sigusr1_count = 0;
  57   proc_run(pid);
  58 }
  59
  60 /**
  61  * Waits for a program to initialize
  62  *  @param name Name of program to wait for
  63  *  @return If waiting was successful or timeout occured
  64  */
  65 static int init_wait(const char *name) {
  66   useconds_t t = 0;
  67   const useconds_t timeout = 10000; // 10 seconds
  68   while (sigusr1_count==0 && t<timeout) {
  69     t += 10;
  70     usleep(10000);
  71   }
  72   return (t<timeout);
  73 }
  74
  75 typedef struct {
  76   int fh;
  77   void *data;
  78   enum {
  79     EXE_ELF
  80   } type;
  81 } exe_t;
  82
  83 static exe_t *exe_create(const char *file) {
  84   exe_t *exe = malloc(sizeof(exe_t*));
  85
  86   // try ELF
  87   exe->data = elf_create(file);
  88   if (exe->data!=NULL) {
  89     exe->type = EXE_ELF;
  90     return exe;
  91   }
  92   else elf_destroy((elf_t*)exe->data);
  93
  94   // not an executable
  95   free(exe);
  96   return NULL;
  97 }
  98
  99 static void *exe_load(exe_t *exe,pid_t pid) {
 100   if (exe->type==EXE_ELF) return elf_load((elf_t*)exe->data,pid);
 101   else return NULL;
 102 }
 103
 104 static void exe_destroy(exe_t *exe) {
 105   if (exe->type==EXE_ELF) elf_destroy((elf_t*)exe->data);
 106 }
 107
 108 static pid_t proc_fork(void *child_entry) {
 109   // Create process
 110
 111   char *name = getname(rpc_curpid);
 112   pid_t pid = proc_create(name,getuidbypid(rpc_curpid),getgidbypid(rpc_curpid),rpc_curpid);
 113
 114   if (pid!=-1) {
 115     // Copy userspace memory
 116     size_t num_pages,i;
 117     void **pages = proc_mempagelist(rpc_curpid,&num_pages);
 118
 119     if (pages!=NULL) {
 120       for (i=0;i<num_pages;i++) {
 121         int writable,swappable;
 122         void *srcp = proc_memget(rpc_curpid,pages[i],NULL,&writable,&swappable,NULL);
 123
 124         if (srcp!=NULL) {
 125           // Map parent's page to init
 126           void *srcv = proc_memmap(1,NULL,srcp,0,0,0);
 127
 128           // Allocate child's page in init's addrspace
 129           void *dstv = proc_memmap(1,NULL,NULL,1,0,0);
 130           void *dstp = mem_getphysaddr(dstv);
 131
 132           // Map child's page to child
 133           proc_memmap(pid,pages[i],dstp,writable,swappable,0);
 134
 135           // Copy
 136           memcpy(dstv,srcv,PAGE_SIZE);
 137
 138           proc_memunmap(1,srcv);
 139           proc_memunmap(1,dstv);
 140         }
 141         else proc_memmap(pid,pages[i],NULL,writable,swappable,0);
 142       }
 143     }
 144
 145     // Set entrypoint of child
 146     proc_jump(pid,child_entry);
 147   }
 148
 149   return pid;
 150 }
 151
 152 static int proc_exec(const char *file,int var) {
 153   dbgmsg("proc_exec(%s,%d)\n",file,var);
 154   // Change process
 155   char *_file = strdup(file);
 156   proc_setname(rpc_curpid,basename(_file));
 157   proc_setvar(rpc_curpid,var);
 158
 159   // Load executable
 160   exe_t *exe = exe_create(file);
 161   if (exe!=NULL) {
 162     // Remove old addrspace
 163     size_t num_pages,i;
 164     void **pages = proc_mempagelist(rpc_curpid,&num_pages);
 165     if (pages!=NULL) {
 166       for (i=0;i<num_pages;i++) proc_memfree(rpc_curpid,pages[i]);
 167     }
 168
 169     void *entrypoint = exe_load(exe,rpc_curpid);
 170
 171     if (entrypoint!=NULL) {
 172       proc_jump(rpc_curpid,entrypoint);
 173       proc_createstack(rpc_curpid);
 174     }
 175     else {
 176       dbgmsg("failed loading executable!");
 177       dbgmsg("TODO: destroy process\n");
 178       while (1);
 179     }
 180
 181     exe_destroy(exe);
 182     return 0;
 183   }
 184   else return errno;
 185 }
 186
 187 static void init_computer_shutdown() {
 188   pid_t child;
 189   while ((child = getchild(0))!=-1) kill(child,SIGKILL);
 190   exit(0);
 191 }
 192
 193 int main(int argc,char *argv[]) {
 194   size_t i;
 195
 196   init_init();
 197   for (i=0;INIT_PROGRAM(i);i++) {
 198     //dbgmsg("init: starting %s...",INIT_PROGRAM(i));
 199     init_run(INIT_PROGRAM(i));
 200
 201     if (!init_wait(INIT_PROGRAM(i))) {
 202       dbgmsg("init: %s does not respond. initialization failed!\n",init_programs[i]);
 203       return 1;
 204     }
 205     //dbgmsg("done\n");
 206
 207     if (strcmp(INIT_PROGRAM(i),"iso9660")==0) {
 208       // Initial mount of boot device
 209       vfs_mount(BOOT_FS,BOOT_MP,BOOT_DEV,BOOT_RO);
 210       sleep(1);
 211     }
 212   }
 213
 214   rpc_func(proc_fork,"i",sizeof(int));
 215   rpc_func(proc_exec,"$i",PATH_MAX+sizeof(int));
 216   rpc_func_create("computer_shutdown",init_computer_shutdown,"",0);
 217
 218   init_run(INIT2_PROGRAM);
 219
 220   rpc_mainloop(-1);
 221
 222   return 0;
 223 }