qemu-wrapper/qemu-wrapper.c

   1 #include <stdio.h>
   2 #include <stdlib.h>
   3 #include <xs.h>
   4 #include <string.h>
   5 #include <fcntl.h>
   6 #include <unistd.h>
   7 #include <sys/mount.h>
   8
   9 #include <dirent.h>
  10
  11 #define MAX_GUEST_CMDLINE 1024
  12 #define PARSE_ARGS(ARGS,START,QUOTE,END) \
  13     c = ARGS; \
  14     quote = 0; \
  15     while (*c) { \
  16         if (*c != ' ') { \
  17             START; \
  18             while (*c) { \
  19                 if (quote) { \
  20                     if (*c == quote) { \
  21                         quote = 0; \
  22                         QUOTE; \
  23                         continue; \
  24                     } \
  25                 } else if (*c == ' ') \
  26                     break; \
  27                 if (*c == '"' || *c == '\'') { \
  28                     quote = *c; \
  29                     QUOTE; \
  30                     continue; \
  31                 } \
  32                 c++; \
  33             } \
  34         } else { \
  35             END; \
  36             while (*c == ' ') \
  37                 c++; \
  38         } \
  39     } \
  40     if (quote) {\
  41         printf("Warning: unterminated quotation %c\n", quote); \
  42         quote = 0; \
  43     }
  44 #define PARSE_ARGS_COUNT(ARGS) PARSE_ARGS(ARGS, argc++, c++, )
  45 #define PARSE_ARGS_STORE(ARGS) PARSE_ARGS(ARGS, argv[argc++] = c, memmove(c, c + 1, strlen(c + 1) + 1), *c++ = 0)
  46
  47 struct xs_handle *xsh=NULL;
  48
  49 int xenbus_read_integer(const char *path)
  50 {
  51     char *buf;
  52     int t;
  53         unsigned int len;
  54
  55     buf = xs_read(xsh,XBT_NULL, path, &len);
  56     if (buf == NULL) {
  57                 printf("Failed to read %s.\n", path);
  58                 free(buf);
  59                 return -1;
  60     }
  61     sscanf(buf, "%d", &t);
  62     free(buf);
  63     return t;
  64 }
  65
  66 int main(void)
  67 {
  68         char *c, quote;
  69         char *domargs;
  70     int argc;
  71     char **argv;
  72     char *envp[] = { NULL };
  73     char *vm;
  74     char path[128];
  75     int domid,fd,i;
  76         unsigned int len;
  77         char cmdline[MAX_GUEST_CMDLINE];
  78
  79         DIR *dp;
  80         struct dirent *dirp;
  81
  82 #if 0
  83         /* read cmdline from /proc/cmdline  */
  84         fd=open("/proc/cmdline",O_RDONLY);
  85         if(fd<0){
  86                 printf("Cannot open /proc/cmdline\n");
  87                 exit(0);
  88         }
  89         if(read(fd,cmdline,MAX_GUEST_CMDLINE) < 0){
  90                 printf("Cannot read cmdline from /proc/cmdline\n");
  91                 exit(0);
  92         }
  93         close(fd);
  94         printf("cmdline(%s)\n",cmdline);
  95 #endif
  96
  97         mount("xenfs","/proc/xen","xenfs",MS_NODEV,"");
  98
  99         printf("printf /dev dir\n");
 100         if((dp=opendir("/dev")) == NULL)
 101         {
 102                 printf("there is no /dev dir\n");
 103                 exit(0);
 104         }
 105         while((dirp=readdir(dp)) != NULL)
 106                 printf("%s  ",dirp->d_name);
 107         closedir(dp);
 108         printf(" end\n");
 109
 110         xsh=xs_daemon_open();
 111         if(xsh==NULL){
 112                 printf("Cannot open xenstore handle\n");
 113                 exit(0);
 114         }
 115
 116     /* Fetch argc, argv from XenStore */
 117     domid = xenbus_read_integer("target");
 118     if (domid == -1) {
 119         printf("Couldn't read target\n");
 120         exit(0);
 121     }
 122
 123     snprintf(path, sizeof(path), "/local/domain/%d/vm", domid);
 124     vm = xs_read(xsh,XBT_NULL, path,&len);
 125     if (!len) {
 126         printf("Couldn't read vm path\n");
 127         exit(0);
 128     }
 129
 130     snprintf(path, sizeof(path), "%s/image/dmargs", vm);
 131     free(vm);
 132
 133     domargs = xs_read(xsh,XBT_NULL, path, &len);
 134     if (!len) {
 135         printf("stubdom args is empty\n");
 136         domargs = strdup("");
 137     }
 138
 139         xs_daemon_close(xsh);
 140
 141         argc = 1;
 142
 143 //      PARSE_ARGS_COUNT(cmdline);
 144         PARSE_ARGS_COUNT(domargs);
 145
 146         argv = alloca((argc + 3) * sizeof(char *));
 147     argv[0] = "main";
 148     argv[1] = "-M";
 149     argv[2] = "xenfv";
 150     argc = 3;
 151
 152 //    PARSE_ARGS_STORE(cmdline)
 153     PARSE_ARGS_STORE(domargs)
 154
 155     argv[argc] = NULL;
 156
 157     for (i = 0; i < argc; i++)
 158                 printf("\"%s\" ", argv[i]);
 159     printf("\n");
 160
 161         execve("/bin/qemu",argv,envp);
 162
 163         return 1;
 164 }