common/promiscuous.c

   1 /*
   2  Copyright (C) 2014-2017 Cédric Schieli
   3
   4  This program is free software; you can redistribute it and/or
   5  modify it under the terms of the GNU Lesser General Public License
   6  as published by the Free Software Foundation; either version 2.1
   7  of the License, or (at your option) any later version.
   8
   9  This program is distributed in the hope that it will be useful,
  10  but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  GNU Lesser General Public License for more details.
  13
  14  You should have received a copy of the GNU General Public License
  15  along with this program; if not, write to the Free Software
  16  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  17
  18 */
  19
  20 #ifndef WIN32
  21 #include <stdlib.h>
  22 #include <unistd.h>
  23 #include <errno.h>
  24 #include <sys/types.h>
  25 #include <sys/stat.h>
  26 #include <fcntl.h>
  27 #include <grp.h>
  28 #ifdef __APPLE__
  29 #include <AvailabilityMacros.h>
  30 #endif
  31 #include "JackError.h"
  32 #endif
  33
  34
  35 int
  36 jack_group2gid(const char* group)
  37 {
  38 #ifdef WIN32
  39     return -1;
  40 #else
  41     size_t buflen;
  42     char *buf;
  43     int ret;
  44     struct group grp;
  45     struct group *result;
  46
  47     if (!group || !*group)
  48         return -1;
  49
  50     ret = strtol(group, &buf, 10);
  51     if (!*buf)
  52         return ret;
  53
  54 /* MacOSX only defines _SC_GETGR_R_SIZE_MAX starting from 10.4 */
  55 #if defined(__APPLE__) && MAC_OS_X_VERSION_MIN_REQUIRED < MAC_OS_X_VERSION_10_4
  56     buflen = 4096;
  57 #else
  58     buflen = sysconf(_SC_GETGR_R_SIZE_MAX);
  59     if (buflen == -1)
  60         buflen = 4096;
  61 #endif
  62     buf = (char*)malloc(buflen);
  63
  64     while (buf && ((ret = getgrnam_r(group, &grp, buf, buflen, &result)) == ERANGE)) {
  65         buflen *= 2;
  66         buf = (char*)realloc(buf, buflen);
  67     }
  68     if (!buf)
  69         return -1;
  70     free(buf);
  71     if (ret || !result)
  72         return -1;
  73     return grp.gr_gid;
  74 #endif
  75 }
  76
  77 #ifndef WIN32
  78 int
  79 jack_promiscuous_perms(int fd, const char* path, gid_t gid)
  80 {
  81         mode_t mode = S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH;
  82         if (gid >= 0) {
  83                 if (((fd < 0) ? chown(path, -1, gid) : fchown(fd, -1, gid)) < 0) {
  84                         jack_log("Cannot chgrp %s: %s. Falling back to permissive perms.", path, strerror(errno));
  85                 } else {
  86                         mode = S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP;
  87                 }
  88         }
  89         if (((fd < 0) ? chmod(path, mode) : fchmod(fd, mode)) < 0) {
  90                 jack_log("Cannot chmod %s: %s. Falling back to default (umask) perms.", path, strerror(errno));
  91                 return -1;
  92         }
  93         return 0;
  94 }
  95 #endif