lib/syscall-legacy.hc

   1 // $Id: syscall-legacy.hc,v 1.1.4.6 2004/02/05 03:52:45 ensc Exp $ --*- c -*--
   2
   3 // Copyright (C) 2003 Enrico Scholz <enrico.scholz@informatik.tu-chemnitz.de>
   4 // based on syscall.cc by Jacques Gelinas
   5 //
   6 // This program is free software; you can redistribute it and/or modify
   7 // it under the terms of the GNU General Public License as published by
   8 // the Free Software Foundation; either version 2, or (at your option)
   9 // any later version.
  10 //
  11 // This program is distributed in the hope that it will be useful,
  12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 // GNU General Public License for more details.
  15 //
  16 // You should have received a copy of the GNU General Public License
  17 // along with this program; if not, write to the Free Software
  18 // Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  19
  20 /*
  21         This tells the system call number for new_s_context and set_ipv4root
  22         using /proc/self/status. This helps until the vserver project is
  23         included officially in the kernel (and has its own syscall).
  24
  25         We rely on /proc/self/status to find the syscall number.
  26
  27         If it is not there, we rely on adm/unistd.h.
  28
  29         If this file does not have those system calls (not a patched kernel source)
  30         we rely on static values in this file.
  31 */
  32 #include "safechroot-internal.hc"
  33
  34 #include <stdio.h>
  35 #include <string.h>
  36 #include <stdlib.h>
  37 #include <errno.h>
  38 #include <syscall.h>
  39 #include <asm/unistd.h>
  40
  41 // Here is the trick. We keep a copy of the define, then undef it
  42 // and then later, we try to locate the value reading /proc/self/status
  43 // If this fails, we have the old preserved copy.
  44 static int def_NR_set_ipv4root = 274;
  45 #undef __NR_set_ipv4root
  46
  47 static int __NR_set_ipv4root_rev0;
  48 static int __NR_set_ipv4root_rev1;
  49 static int __NR_set_ipv4root_rev2;
  50 static int __NR_set_ipv4root_rev3;
  51 static int rev_ipv4root=0;
  52
  53 #ifdef ENSC_SYSCALL_TRADITIONAL
  54 inline static int
  55 set_ipv4root_rev0(unsigned long ip)
  56 {
  57   return syscall(__NR_set_ipv4root_rev0, ip);
  58 }
  59
  60 inline static int
  61 set_ipv4root_rev1(unsigned long ip, unsigned long bcast)
  62 {
  63   return syscall(__NR_set_ipv4root_rev1, ip, bcast);
  64 }
  65
  66 inline static int
  67 set_ipv4root_rev2(unsigned long *ip, int nb, unsigned long bcast)
  68 {
  69   return syscall(__NR_set_ipv4root_rev2, ip, nb, bcast);
  70 }
  71
  72 inline static int
  73 set_ipv4root_rev3(unsigned long *ip, int nb, unsigned long bcast, unsigned long * mask)
  74 {
  75   return syscall(__NR_set_ipv4root_rev3, ip, nb, bcast, mask);
  76 }
  77
  78 #else
  79 inline static _syscall1(int, set_ipv4root_rev0, unsigned long, ip)
  80 inline static _syscall2(int, set_ipv4root_rev1, unsigned long, ip, unsigned long, bcast)
  81 inline static _syscall3(int, set_ipv4root_rev2, unsigned long *, ip, int, nb, unsigned long, bcast)
  82 inline static _syscall4(int, set_ipv4root_rev3, unsigned long *, ip, int, nb, unsigned long, bcast, unsigned long *, mask)
  83 #endif
  84
  85 static int def_NR_new_s_context = 273;
  86 #undef __NR_new_s_context
  87 static int __NR_new_s_context_rev0;
  88   //static int __NR_new_s_context_rev1;
  89 static int rev_s_context=0;
  90
  91 #ifdef ENSC_SYSCALL_TRADITIONAL
  92 inline static int
  93 new_s_context_rev0(int newctx, int remove_cap, int flags)
  94 {
  95   return syscall(__NR_new_s_context_rev0, newctx, remove_cap, flags);
  96 }
  97 #else
  98 inline static _syscall3(int, new_s_context_rev0, int, newctx, int, remove_cap, int, flags)
  99     //static _syscall4(int, new_s_context_rev1, int, nbctx, int *, ctxs, int, remove_cap, int, flags)
 100 #endif
 101
 102 #if 0
 103 #undef __NR_set_ctxlimit
 104 static int __NR_set_ctxlimit=-1;
 105 static int rev_set_ctxlimit=-1;
 106
 107 static _syscall2 (int, set_ctxlimit, int, resource, long, limit)
 108 #endif
 109
 110 static void init()
 111 {
 112         static int is_init = 0;
 113         if (!is_init){
 114                 FILE *fin = fopen ("/proc/self/status","r");
 115                 __NR_set_ipv4root_rev0 = def_NR_set_ipv4root;
 116                 __NR_set_ipv4root_rev1 = def_NR_set_ipv4root;
 117                 __NR_set_ipv4root_rev2 = def_NR_set_ipv4root;
 118                 __NR_set_ipv4root_rev3 = def_NR_set_ipv4root;
 119                 __NR_new_s_context_rev0 = def_NR_new_s_context;
 120                   //__NR_new_s_context_rev1 = def_NR_new_s_context;
 121                 if (fin != NULL){
 122                         char line[100];
 123                         while (fgets(line,sizeof(line)-1,fin)!=NULL){
 124                                 int num;
 125                                 char title[100],rev[100];
 126                                 rev[0] = '\0';
 127                                 if (sscanf(line,"%s %d %s",title,&num,rev)>=2){
 128                                         if (strcmp(title,"__NR_set_ipv4root:")==0){
 129                                                 __NR_set_ipv4root_rev0 = num;
 130                                                 __NR_set_ipv4root_rev1 = num;
 131                                                 __NR_set_ipv4root_rev2 = num;
 132                                                 __NR_set_ipv4root_rev3 = num;
 133                                                 if (strncmp(rev,"rev",3)==0){
 134                                                         rev_ipv4root = atoi(rev+3);
 135                                                 }
 136 #if 0
 137                                         }else if (strcmp(title,"__NR_set_ctxlimit:")==0){
 138                                                 __NR_set_ctxlimit = num;
 139                                                 if (strncmp(rev,"rev",3)==0){
 140                                                         rev_set_ctxlimit = atoi(rev+3);
 141                                                 }
 142 #endif
 143                                         }else if (strcmp(title,"__NR_new_s_context:")==0){
 144                                                 __NR_new_s_context_rev0 = num;
 145                                                   //__NR_new_s_context_rev1 = num;
 146                                                 if (strncmp(rev,"rev",3)==0){
 147                                                         rev_s_context = atoi(rev+3);
 148                                                 }
 149                                         }
 150                                 }
 151                         }
 152                         fclose (fin);
 153                 }
 154                 is_init = 1;
 155         }
 156 }
 157
 158 void vc_init_legacy()
 159 {
 160         init();
 161 }
 162
 163 static ALWAYSINLINE int
 164 vc_new_s_context_legacy(int ctx, int remove_cap, int flags)
 165 {
 166         int ret = -1;
 167         init();
 168         if (rev_s_context == 0){
 169                 return new_s_context_rev0(ctx, remove_cap, flags);
 170         }else{
 171                 errno = -ENOSYS;
 172                 ret   = -1;
 173         }
 174         return ret;
 175 }
 176
 177 static ALWAYSINLINE int
 178 vc_set_ipv4root_legacy_internal (
 179         unsigned long ip[],
 180         int nb,
 181         unsigned long bcast,
 182         unsigned long mask[])
 183 {
 184         init();
 185         if (rev_ipv4root == 0){
 186                 if (nb > 1){
 187                         fprintf (stderr,"set_ipv4root: Several IP number specified, but this kernel only supports one. Ignored\n");
 188                 }
 189                 return set_ipv4root_rev0 (ip[0]);
 190         }else if (rev_ipv4root == 1){
 191                 if (nb > 1){
 192                         fprintf (stderr,"set_ipv4root: Several IP number specified, but this kernel only supports one. Ignored\n");
 193                 }
 194                 return set_ipv4root_rev1 (ip[0],bcast);
 195         }else if (rev_ipv4root == 2){
 196                 return set_ipv4root_rev2 (ip,nb,bcast);
 197         }else if (rev_ipv4root == 3){
 198                 return set_ipv4root_rev3 (ip,nb,bcast,mask);
 199         }
 200         errno = EINVAL;
 201         return -1;
 202 }
 203
 204 static ALWAYSINLINE int
 205 vc_set_ipv4root_legacy(uint32_t  bcast, size_t nb, struct vc_ip_mask_pair const *ips)
 206 {
 207   unsigned long ip[nb];
 208   unsigned long mask[nb];
 209   size_t                i;
 210
 211   for (i=0; i<nb; ++i) {
 212     ip[i]   = ips[i].ip;
 213     mask[i] = ips[i].mask;
 214   }
 215
 216   return vc_set_ipv4root_legacy_internal(ip, nb, bcast, mask);
 217 }