nsz Git - musl/blob - src/passwd/getgr_r.c

   1 #include "pwf.h"
   2 #include <pthread.h>
   3
   4 #define FIX(x) (gr->gr_##x = gr->gr_##x-line+buf)
   5
   6 static int getgr_r(const char *name, gid_t gid, struct group *gr, char *buf, size_t size, struct group **res)
   7 {
   8         FILE *f;
   9         char *line = 0;
  10         size_t len = 0;
  11         char **mem = 0;
  12         size_t nmem = 0;
  13         int rv = 0;
  14         size_t i;
  15         int cs;
  16
  17         pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs);
  18
  19         f = fopen("/etc/group", "rb");
  20         if (!f) {
  21                 rv = errno;
  22                 goto done;
  23         }
  24
  25         *res = 0;
  26         while (__getgrent_a(f, gr, &line, &len, &mem, &nmem)) {
  27                 if (name && !strcmp(name, gr->gr_name)
  28                 || !name && gr->gr_gid == gid) {
  29                         if (size < len + nmem*sizeof(char *) + 32) {
  30                                 rv = ERANGE;
  31                                 break;
  32                         }
  33                         *res = gr;
  34                         buf += (16-(uintptr_t)buf)%16;
  35                         gr->gr_mem = (void *)buf;
  36                         buf += nmem*sizeof(char *);
  37                         memcpy(buf, line, len);
  38                         FIX(name);
  39                         FIX(passwd);
  40                         for (i=0; mem[i]; i++)
  41                                 gr->gr_mem[i] = mem[i]-line+buf;
  42                         gr->gr_mem[i] = 0;
  43                         break;
  44                 }
  45         }
  46         free(mem);
  47         free(line);
  48         fclose(f);
  49 done:
  50         pthread_setcancelstate(cs, 0);
  51         return rv;
  52 }
  53
  54 int getgrnam_r(const char *name, struct group *gr, char *buf, size_t size, struct group **res)
  55 {
  56         return getgr_r(name, 0, gr, buf, size, res);
  57 }
  58
  59 int getgrgid_r(gid_t gid, struct group *gr, char *buf, size_t size, struct group **res)
  60 {
  61         return getgr_r(0, gid, gr, buf, size, res);
  62 }