apps/init/procfs.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 <fuse.h>
  22 #include <llist.h>
  23 #include <stdlib.h>
  24 #include <path.h>
  25 #include <proc.h>
  26 #include <stdio.h>
  27
  28 #include "init.h"
  29
  30 #define PROCFS_NAME       "procfs"
  31 #define PROCFS_MOUNTPOINT "/proc"
  32
  33 typedef struct procfs_path_S procfs_path_t;
  34
  35 typedef struct {
  36   pid_t pid;
  37   char *exe;
  38   char *name;
  39   uid_t uid;
  40   gid_t gid;
  41 } procfs_proc_t;
  42
  43 typedef enum {
  44   PROCFS_FILE,
  45   PROCFS_DIR,
  46   PROCFS_SYMLINK
  47 } procfs_ftype_t;
  48
  49 typedef struct {
  50   const char *name;
  51   procfs_ftype_t ftype;
  52   struct {
  53     int (*cb_read)(procfs_path_t *path,char *buf,size_t size,off_t offset);
  54     int (*cb_write)(procfs_path_t *path,const char *buf,size_t size,off_t offset);
  55   } file;
  56   struct {
  57     int (*cb_readdir)(procfs_path_t *path,void *buf,fuse_fill_dir_t filler,off_t offset);
  58   } dir;
  59   struct {
  60   } symlink;
  61 } procfs_file_t;
  62
  63 struct procfs_path_S {
  64   pid_t pid;
  65   procfs_proc_t *proc;
  66   procfs_file_t *file;
  67   const char *subfile;
  68   int isdir;
  69 };
  70
  71 static int procfs_loginuid_read(procfs_path_t *path,char *buf,size_t size,off_t offset);
  72 static int procfs_mem_read(procfs_path_t *path,char *buf,size_t size,off_t offset);
  73 static int procfs_mem_write(procfs_path_t *path,const char *buf,size_t size,off_t offset);
  74 static procfs_file_t procfs_files[] = {
  75   { .name = "cwd", .ftype = PROCFS_SYMLINK },
  76   { .name = "exe", .ftype = PROCFS_SYMLINK },
  77   { .name = "loginuid", .ftype = PROCFS_FILE, .file = { .cb_read = procfs_loginuid_read } },
  78   { .name = "mem", .ftype = PROCFS_FILE, .file = { .cb_read = procfs_mem_read, .cb_write = procfs_mem_write } },
  79   { .name = NULL }
  80 };
  81
  82 static llist_t procfs_processes;
  83
  84 static int procfs_loginuid_read(procfs_path_t *path,char *buf,size_t size,off_t offset) {
  85   return 0;
  86 }
  87
  88 static int procfs_mem_read(procfs_path_t *path,char *buf,size_t size,off_t offset) {
  89   return 0;
  90 }
  91
  92 static int procfs_mem_write(procfs_path_t *path,const char *buf,size_t size,off_t offset) {
  93   return 0;
  94 }
  95
  96 static procfs_proc_t *procfs_proc_find(pid_t pid) {
  97   size_t i;
  98   procfs_proc_t *proc;
  99   for (i=0;(proc = llist_get(procfs_processes,i));i++) {
 100     if (proc->pid==pid) return proc;
 101   }
 102   return NULL;
 103 }
 104
 105 int procfs_proc_new(pid_t pid,const char *name,const char *exe) {
 106   procfs_proc_t *proc = malloc(sizeof(procfs_proc_t));
 107   proc->pid = pid;
 108   proc->uid = getuidbypid(pid);
 109   proc->gid = getgidbypid(pid);
 110   if (name==NULL) proc->name = getname(pid);
 111   else proc->name = strdup(name);
 112   if (exe==NULL) proc->exe = NULL;
 113   else proc->exe = strdup(exe);
 114   llist_push(procfs_processes,proc);
 115   return 0;
 116 }
 117
 118 int procfs_proc_update(pid_t pid,const char *name,const char *exe) {
 119   procfs_proc_t *proc = procfs_proc_find(pid);
 120   if (proc!=NULL) {
 121     if (name!=NULL) {
 122       free(proc->name);
 123       proc->name = strdup(name);
 124     }
 125     if (exe!=NULL) {
 126       free(proc->exe);
 127       proc->exe = strdup(exe);
 128     }
 129     return 0;
 130   }
 131   else return -1;
 132 }
 133
 134 static void procfs_parse_path(const char *strpath,procfs_path_t *path) {
 135   path_t *tpath = path_parse(strpath);
 136   path_reject_dots(tpath);
 137
 138   memset(path,0,sizeof(procfs_path_t));
 139   path->isdir = 1;
 140   if (tpath->num_parts>0) {
 141     if (strcmp(tpath->parts[0],"self")==0) {
 142       path->pid = fuse_current_context->pid;
 143     }
 144     else {
 145       path->pid = strtoul(tpath->parts[0],NULL,10);
 146     }
 147     path->proc = procfs_proc_find(path->pid);
 148     //path->isdir = 1;
 149   }
 150   if (tpath->num_parts>1) {
 151     size_t i;
 152     for (i=0;procfs_files[i].name!=NULL;i++) {
 153       if (strcmp(tpath->parts[1],procfs_files[i].name)==0) {
 154         path->file = procfs_files+i;
 155         path->isdir = (path->file->ftype==PROCFS_DIR);
 156       }
 157     }
 158   }
 159   if (tpath->num_parts>2) {
 160     static char subfile_buf[256];
 161     strncpy(subfile_buf,tpath->parts[2],256);
 162     path->subfile = subfile_buf;
 163     path->isdir = 0;
 164   }
 165
 166   path_destroy(tpath);
 167 }
 168
 169 static int procfs_open(const char *strpath,struct fuse_file_info *fi) {
 170   procfs_path_t path;
 171
 172   if (path.pid!=0 && path.proc!=NULL) return -ENOENT;
 173   else if (path.isdir) return -EISDIR;
 174   else return 0;
 175 }
 176
 177 static int procfs_close(const char *path,struct fuse_file_info *fi) {
 178   return 0;
 179 }
 180
 181 static int procfs_read(const char *strpath,char *buf,size_t count,off_t offset,struct fuse_file_info *fi) {
 182   procfs_path_t path;
 183   procfs_parse_path(strpath,&path);
 184
 185   if (path.pid!=0 && path.proc!=NULL) return -ENOENT;
 186   else if (path.isdir) return -EISDIR;
 187   else {
 188     if (path.file->file.cb_read!=NULL) return path.file->file.cb_read(&path,buf,count,offset);
 189     else return -ENOSYS;
 190   }
 191 }
 192
 193 static int procfs_write(const char *strpath,const char *buf,size_t count,off_t offset,struct fuse_file_info *fi) {
 194   procfs_path_t path;
 195   procfs_parse_path(strpath,&path);
 196
 197   if (path.pid!=0 && path.proc!=NULL) return -ENOENT;
 198   else if (path.isdir) return -EISDIR;
 199   else {
 200     if (path.file->file.cb_write!=NULL) return path.file->file.cb_write(&path,buf,count,offset);
 201     else return -ENOSYS;
 202   }
 203 }
 204
 205 static int procfs_readdir(const char *strpath,void *buf,fuse_fill_dir_t filler,off_t offset,struct fuse_file_info *fi) {
 206   procfs_path_t path;
 207   procfs_parse_path(strpath,&path);
 208
 209   if (!path.isdir) return -ENOTDIR;
 210   else if (path.pid==0) {
 211     // list all processes
 212     size_t i;
 213     procfs_proc_t *proc;
 214     struct stat stbuf = {
 215       /// @todo correct permissions
 216       .st_mode = S_IFDIR|0777,
 217     };
 218     for (i=0;(proc = llist_get(procfs_processes,i));i++) {
 219       char str_pid[16];
 220       snprintf(str_pid,16,"%d",proc->pid);
 221       stbuf.st_uid = proc->uid;
 222       stbuf.st_gid = proc->gid;
 223       filler(buf,str_pid,&stbuf,0);
 224     }
 225     return 0;
 226   }
 227   else if (path.proc!=NULL) return -ENOENT;
 228   else {
 229     if (path.file->dir.cb_readdir!=NULL) return path.file->dir.cb_readdir(&path,buf,filler,offset);
 230     else return -ENOSYS;
 231   }
 232 }
 233
 234 static int procfs_getattr(const char *strpath,struct stat *stbuf) {
 235   procfs_path_t path;
 236   procfs_parse_path(strpath,&path);
 237
 238   memset(stbuf,0,sizeof(struct stat));
 239
 240   if (path.file!=NULL) {
 241     if (path.file->ftype==PROCFS_DIR) stbuf->st_mode = S_IFDIR;
 242     else if (path.file->ftype==PROCFS_SYMLINK) stbuf->st_mode = S_IFLNK;
 243     else stbuf->st_mode = S_IFREG;
 244   }
 245   else stbuf->st_mode = S_IFDIR;
 246
 247   /// @todo correct permissions
 248   stbuf->st_mode |= 0777;
 249
 250   return 0;
 251 }
 252
 253 int procfs_init(pid_t *grub_modules) {
 254   size_t i;
 255   pid_t pid;
 256
 257   procfs_processes = llist_create();
 258
 259   // put init itself in process list
 260   procfs_proc_new(1,"init",NULL);
 261
 262   // put GRUB modules in process list
 263   for (i=0;(pid = grub_modules[i])!=0;i++) {
 264     procfs_proc_new(pid,NULL,NULL);
 265   }
 266
 267   return 0;
 268 }
 269
 270 int procfs_run(void) {
 271   // start FUSE
 272   struct fuse_operations devfs_oper = {
 273     .open = procfs_open,
 274     .release = procfs_close,
 275     .read = procfs_read,
 276     .write = procfs_write,
 277     .readdir = procfs_readdir,
 278     .getattr = procfs_getattr
 279   };
 280
 281   // fake argc/argv
 282   int fake_argc = 2;
 283   char *fake_argv[2] = { PROCFS_NAME,PROCFS_MOUNTPOINT };
 284   fuse_main(fake_argc,fake_argv,&devfs_oper,NULL);
 285
 286   return 0;
 287 }