AcessNative/libacess-native.so_src/main.c

   1 /*
   2  */
   3 #include <stdarg.h>
   4 #include <stdlib.h>
   5 #include <stdio.h>
   6 #include <string.h>
   7 #include <unistd.h>
   8 #include <stdbool.h>
   9 #include "common.h"
  10 #include <stdint.h>
  11 #include "../ld-acess_src/exports.h"
  12
  13 extern int      gbSyscallDebugEnabled;
  14
  15 #ifdef __WINDOWS__
  16 int DllMain(void)
  17 {
  18         fprintf(stderr, "TODO: Windows libacessnative setup\n");
  19         return 0;
  20 }
  21
  22 #endif
  23
  24 #ifdef __linux__
  25 int __attribute__ ((constructor(102))) libacessnative_init(int argc, char *argv[], char **envp);
  26
  27 const char *getenv_p(char **envp, const char *name)
  28 {
  29         size_t  namelen = strlen(name);
  30         for(; *envp; envp ++)
  31         {
  32                 if( strncmp(*envp, name, namelen) != 0 )
  33                         continue ;
  34                 if( (*envp)[namelen] != '=' )
  35                         continue ;
  36                 return (*envp)+namelen+1;
  37         }
  38         return 0;
  39 }
  40
  41 int libacessnative_init(int argc, char *argv[], char **envp)
  42 {
  43         Request_Preinit();
  44
  45         //gbSyscallDebugEnabled = 1;
  46
  47         const char *preopens = getenv_p(envp, ENV_VAR_PREOPENS);
  48         printf("preopens = %s\n", preopens);
  49         if( preopens )
  50         {
  51                  int    exp_fd = 0;
  52                 while( *preopens )
  53                 {
  54                         const char *splitter = strchr(preopens, ':');
  55                         size_t  len;
  56                         if( !splitter ) {
  57                                 len = strlen(preopens);
  58                         }
  59                         else {
  60                                 len = splitter - preopens;
  61                         }
  62                         char path[len+1];
  63                         memcpy(path, preopens, len);
  64                         path[len] = 0;
  65                         int fd = acess__SysOpen(path, 6);       // WRITE,READ,no EXEC
  66                         if( fd == -1 ) {
  67                                 fprintf(stderr, "Unable to preopen '%s' errno=%i\n", path, acess__errno);
  68                                 exit(1);
  69                         }
  70                         if( fd != exp_fd ) {
  71                                 //  Oh... this is bad
  72                                 fprintf(stderr, "Pre-opening '%s' resulted in an incorrect FD (expected %i, got %i)",
  73                                         path, exp_fd, fd);
  74                                 exit(1);
  75                         }
  76                         exp_fd += 1;
  77
  78                         if( !splitter )
  79                                 break;
  80                         preopens = splitter + 1;
  81                 }
  82         }
  83
  84 //      if( !getenv(ENV_VAR_KEY)
  85
  86         return 0;
  87 }
  88 #endif
  89
  90 int acessnative_spawn(const char *Binary, int SyscallID, const char * const * argv, const char * const * envp)
  91 {
  92          int    envc = 0;
  93         while( envp && envp[envc++] )
  94                 envc ++;
  95
  96         // Set environment variables for libacess-native
  97         // > ACESSNATIVE_KEY=`newID`
  98         size_t keystr_len = snprintf(NULL, 0, "%s=%i", ENV_VAR_KEY, SyscallID);
  99         char keystr[keystr_len+1];
 100         snprintf(keystr, keystr_len+1, "%s=%i", ENV_VAR_KEY, SyscallID);
 101         bool    bKeyHit = false;
 102
 103         const char *newenv[envc+2+1];
 104          int    i = 0;
 105         for( ; envp && envp[i]; i ++ )
 106         {
 107                 const char      *ev = envp[i];
 108                 if( strncmp(ev, ENV_VAR_KEY"=", sizeof(ENV_VAR_KEY"=")) == 0 ) {
 109                         ev = keystr;
 110                         bKeyHit = true;
 111                 }
 112                 newenv[i] = ev;
 113         }
 114         if( !bKeyHit )
 115                 newenv[i++] = keystr;
 116         newenv[i++] = getenv("LD_LIBRARY_PATH") - (sizeof("LD_LIBRARY_PATH=")-1);       // VERY hacky
 117         newenv[i] = NULL;
 118
 119         // TODO: Detect native_spawn failing
 120         return native_spawn(Binary, argv, newenv);
 121 }
 122
 123 void Debug(const char *format, ...)
 124 {
 125         va_list args;
 126         printf("Debug: ");
 127         va_start(args, format);
 128         vfprintf(stdout, format, args);
 129         va_end(args);
 130         printf("\n");
 131 }
 132
 133 void Warning(const char *format, ...)
 134 {
 135         va_list args;
 136         printf("Warning: ");
 137         va_start(args, format);
 138         vfprintf(stdout, format, args);
 139         va_end(args);
 140         printf("\n");
 141 }
 142