support/pwd.c

   1 /*
   2  * <pwd.h> wrapper functions.
   3  *
   4  * Authors:
   5  *   Jonathan Pryor (jonpryor@vt.edu)
   6  *
   7  * Copyright (C) 2004 Jonathan Pryor
   8  */
   9
  10 #include <pwd.h>
  11 #include <errno.h>
  12 #include <string.h>
  13 #include <stdio.h>
  14 #include <stdlib.h>
  15
  16 #include "mph.h"
  17
  18 G_BEGIN_DECLS
  19
  20 struct Mono_Posix_Syscall__Passwd {
  21         /* string */ char      *pw_name;
  22         /* string */ char      *pw_passwd;
  23         /* uid_t  */ mph_uid_t  pw_uid;
  24         /* gid_t  */ mph_gid_t  pw_gid;
  25         /* string */ char      *pw_gecos;
  26         /* string */ char      *pw_dir;
  27         /* string */ char      *pw_shell;
  28         /* string */ char      *_pw_buf_;
  29 };
  30
  31 /*
  32  * Copy the native `passwd' structure to it's managed representation.
  33  *
  34  * To minimize separate mallocs, all the strings are allocated within the same
  35  * memory block (stored in _pw_buf_).
  36  */
  37 static int
  38 copy_passwd (struct Mono_Posix_Syscall__Passwd *to, struct passwd *from)
  39 {
  40         enum {PW_NAME = 0, PW_PASSWD, PW_GECOS, PW_DIR, PW_SHELL, PW_LAST};
  41         size_t buflen, len[PW_LAST];
  42         /* bool */ unsigned char copy[PW_LAST] = {0};
  43         const char *source[PW_LAST];
  44         char **dest[PW_LAST];
  45         int i;
  46         char *cur;
  47
  48         to->pw_uid    = from->pw_uid;
  49         to->pw_gid    = from->pw_gid;
  50
  51         to->pw_name   = NULL;
  52         to->pw_passwd = NULL;
  53         to->pw_gecos  = NULL;
  54         to->pw_dir    = NULL;
  55         to->pw_shell  = NULL;
  56         to->_pw_buf_  = NULL;
  57
  58         source[PW_NAME]   = from->pw_name;
  59         source[PW_PASSWD] = from->pw_passwd;
  60         source[PW_GECOS]  = from->pw_gecos;
  61         source[PW_DIR]    = from->pw_dir;
  62         source[PW_SHELL]  = from->pw_shell;
  63
  64         dest[PW_NAME]   = &to->pw_name;
  65         dest[PW_PASSWD] = &to->pw_passwd;
  66         dest[PW_GECOS]  = &to->pw_gecos;
  67         dest[PW_DIR]    = &to->pw_dir;
  68         dest[PW_SHELL]  = &to->pw_shell;
  69
  70         buflen = PW_LAST;
  71
  72         /* over-rigorous checking for integer overflow */
  73         for (i = 0; i != PW_LAST; ++i) {
  74                 len[i] = strlen (source[i]);
  75                 if (len[i] < INT_MAX - buflen) {
  76                         buflen += len[i];
  77                         copy[i] = 1;
  78                 }
  79         }
  80
  81         cur = to->_pw_buf_ = (char*) malloc (buflen);
  82         if (cur == NULL) {
  83                 return -1;
  84         }
  85
  86         for (i = 0; i != PW_LAST; ++i) {
  87                 if (copy[i]) {
  88                         *dest[i] = strcpy (cur, source[i]);
  89                         cur += (len[i] + 1);
  90                 }
  91         }
  92
  93         return 0;
  94 }
  95
  96 gint32
  97 Mono_Posix_Syscall_getpwnam (const char *name, struct Mono_Posix_Syscall__Passwd *pwbuf)
  98 {
  99         struct passwd *pw;
 100
 101         if (pwbuf == NULL) {
 102                 errno = EFAULT;
 103                 return -1;
 104         }
 105
 106         pw = getpwnam (name);
 107         if (pw == NULL)
 108                 return -1;
 109
 110         if (copy_passwd (pwbuf, pw) == -1) {
 111                 errno = ENOMEM;
 112                 return -1;
 113         }
 114         return 0;
 115 }
 116
 117 gint32
 118 Mono_Posix_Syscall_getpwuid (mph_uid_t uid, struct Mono_Posix_Syscall__Passwd *pwbuf)
 119 {
 120         struct passwd *pw;
 121
 122         if (pwbuf == NULL) {
 123                 errno = EFAULT;
 124                 return -1;
 125         }
 126
 127         errno = 0;
 128         pw = getpwuid (uid);
 129         if (pw == NULL) {
 130                 return -1;
 131         }
 132
 133         if (copy_passwd (pwbuf, pw) == -1) {
 134                 errno = ENOMEM;
 135                 return -1;
 136         }
 137         return 0;
 138 }
 139
 140 #ifdef HAVE_GETPWNAM_R
 141 gint32
 142 Mono_Posix_Syscall_getpwnam_r (const char *name,
 143         struct Mono_Posix_Syscall__Passwd *pwbuf,
 144         struct passwd **pwbufp)
 145 {
 146         char *buf, *buf2;
 147         size_t buflen;
 148         int r;
 149         struct passwd _pwbuf;
 150
 151         if (pwbuf == NULL) {
 152                 errno = EFAULT;
 153                 return -1;
 154         }
 155
 156         buf = buf2 = NULL;
 157         buflen = 2;
 158
 159         do {
 160                 buf2 = realloc (buf, buflen *= 2);
 161                 if (buf2 == NULL) {
 162                         free (buf);
 163                         errno = ENOMEM;
 164                         return -1;
 165                 }
 166                 buf = buf2;
 167         } while ((r = getpwnam_r (name, &_pwbuf, buf, buflen, pwbufp)) &&
 168                         recheck_range (r));
 169
 170         if (r == 0 && copy_passwd (pwbuf, &_pwbuf) == -1)
 171                 r = errno = ENOMEM;
 172         free (buf);
 173
 174         return r;
 175 }
 176 #endif /* ndef HAVE_GETPWNAM_R */
 177
 178 #ifdef HAVE_GETPWUID_R
 179 gint32
 180 Mono_Posix_Syscall_getpwuid_r (mph_uid_t uid,
 181         struct Mono_Posix_Syscall__Passwd *pwbuf,
 182         struct passwd **pwbufp)
 183 {
 184         char *buf, *buf2;
 185         size_t buflen;
 186         int r;
 187         struct passwd _pwbuf;
 188
 189         if (pwbuf == NULL) {
 190                 errno = EFAULT;
 191                 return -1;
 192         }
 193
 194         buf = buf2 = NULL;
 195         buflen = 2;
 196
 197         do {
 198                 buf2 = realloc (buf, buflen *= 2);
 199                 if (buf2 == NULL) {
 200                         free (buf);
 201                         errno = ENOMEM;
 202                         return -1;
 203                 }
 204                 buf = buf2;
 205         } while ((r = getpwuid_r (uid, &_pwbuf, buf, buflen, pwbufp)) &&
 206                         recheck_range (r));
 207
 208         if (r == 0 && copy_passwd (pwbuf, &_pwbuf) == -1)
 209                 r = errno = ENOMEM;
 210         free (buf);
 211
 212         return r;
 213 }
 214 #endif /* ndef HAVE_GETPWUID_R */
 215
 216 gint32
 217 Mono_Posix_Syscall_getpwent (struct Mono_Posix_Syscall__Passwd *pwbuf)
 218 {
 219         struct passwd *pw;
 220
 221         if (pwbuf == NULL) {
 222                 errno = EFAULT;
 223                 return -1;
 224         }
 225
 226         pw = getpwent ();
 227         if (pw == NULL)
 228                 return -1;
 229
 230         if (copy_passwd (pwbuf, pw) == -1) {
 231                 errno = ENOMEM;
 232                 return -1;
 233         }
 234         return 0;
 235 }
 236
 237 #ifdef HAVE_FGETPWENT
 238 gint32
 239 Mono_Posix_Syscall_fgetpwent (FILE *stream, struct Mono_Posix_Syscall__Passwd *pwbuf)
 240 {
 241         struct passwd *pw;
 242
 243         if (pwbuf == NULL) {
 244                 errno = EFAULT;
 245                 return -1;
 246         }
 247
 248         pw = fgetpwent (stream);
 249         if (pw == NULL)
 250                 return -1;
 251
 252         if (copy_passwd (pwbuf, pw) == -1) {
 253                 errno = ENOMEM;
 254                 return -1;
 255         }
 256         return 0;
 257 }
 258 #endif /* ndef HAVE_FGETPWENT */
 259
 260 G_END_DECLS
 261
 262 /*
 263  * vim: noexpandtab
 264  */