/* grp.cc Copyright 1996, 1997, 1998, 2000 Cygnus Solutions. Original stubs by Jason Molenda of Cygnus Support, crash@cygnus.com First implementation by Gunther Ebert, gunther.ebert@ixos-leipzig.de This file is part of Cygwin. This software is a copyrighted work licensed under the terms of the Cygwin license. Please consult the file "CYGWIN_LICENSE" for details. */ #include "winsup.h" #include #include #include #include #include "sync.h" #include "sigproc.h" #include "pinfo.h" #include "cygheap.h" #include "cygerrno.h" #include "security.h" /* Read /etc/group only once for better performance. This is done on the first call that needs information from it. */ #define MAX_DOMAIN_NAME 100 static NO_COPY const char *etc_group = "/etc/group"; static struct group *group_buf = NULL; /* group contents in memory */ static int curr_lines = 0; static int max_lines = 0; /* Position in the group cache */ #ifdef _MT_SAFE #define grp_pos _reent_winsup()->_grp_pos #else static int grp_pos = 0; #endif /* Set to 1 when /etc/group has been read in by read_etc_group (). */ /* Functions in this file need to check the value of group_in_memory_p and read in the group file if it isn't set. */ /* FIXME: This should be static but this is called in uinfo_init outside this file */ int group_in_memory_p = 0; static int parse_grp (struct group &grp, const char *line) { int len = strlen(line); char *newline = (char *) malloc (len + 1); (void) memcpy (newline, line, len + 1); if (newline[--len] == '\n') newline[len] = '\0'; char *dp = strchr (newline, ':'); if (!dp) return 0; *dp++ = '\0'; grp.gr_name = newline; grp.gr_passwd = dp; dp = strchr (grp.gr_passwd, ':'); if (dp) { *dp++ = '\0'; if (!strlen (grp.gr_passwd)) grp.gr_passwd = NULL; grp.gr_gid = strtol (dp, NULL, 10); dp = strchr (dp, ':'); if (dp) { if (*++dp) { int i = 0; char *cp; for (cp = dp; (cp = strchr (cp, ',')) != NULL; ++cp) ++i; char **namearray = (char **) calloc (i + 2, sizeof (char *)); if (namearray) { i = 0; for (cp = dp; (cp = strchr (dp, ',')) != NULL; dp = cp + 1) { *cp = '\0'; namearray[i++] = dp; } namearray[i++] = dp; namearray[i] = NULL; } grp.gr_mem = namearray; } else grp.gr_mem = (char **) calloc (1, sizeof (char *)); return 1; } } return 0; } /* Read one line from /etc/group into the group cache */ static void add_grp_line (const char *line) { if (curr_lines == max_lines) { max_lines += 10; group_buf = (struct group *) realloc (group_buf, max_lines * sizeof (struct group)); } if (parse_grp (group_buf[curr_lines], line)) curr_lines++; } extern PSID get_admin_sid (); /* Cygwin internal */ /* Read in /etc/group and save contents in the group cache */ /* This sets group_in_memory_p to 1 so functions in this file can tell that /etc/group has been read in */ /* FIXME: should be static but this is called in uinfo_init outside this file */ void read_etc_group () { extern int group_sem; char linebuf [200]; char group_name [MAX_USER_NAME]; DWORD group_name_len = MAX_USER_NAME; strncpy (group_name, "Administrators", sizeof (group_name)); ++group_sem; FILE *f = fopen (etc_group, "rt"); --group_sem; if (f) { while (fgets (linebuf, sizeof (linebuf), f) != NULL) { if (strlen (linebuf)) add_grp_line (linebuf); } fclose (f); } else /* /etc/group doesn't exist -- create default one in memory */ { char domain_name [MAX_DOMAIN_NAME]; DWORD domain_name_len = MAX_DOMAIN_NAME; SID_NAME_USE acType; debug_printf ("Emulating /etc/group"); if (! LookupAccountSidA (NULL , get_admin_sid () , group_name, &group_name_len, domain_name, &domain_name_len, &acType)) { strcpy (group_name, "unknown"); debug_printf ("Failed to get local admins group name. %E"); } snprintf (linebuf, sizeof (linebuf), "%s::%u:\n", group_name, DEFAULT_GID); add_grp_line (linebuf); } group_in_memory_p = 1; } extern "C" struct group * getgrgid (gid_t gid) { struct group * default_grp = NULL; if (!group_in_memory_p) read_etc_group(); for (int i = 0; i < curr_lines; i++) { if (group_buf[i].gr_gid == DEFAULT_GID) default_grp = group_buf + i; if (group_buf[i].gr_gid == gid) return group_buf + i; } return default_grp; } extern "C" struct group * getgrnam (const char *name) { if (!group_in_memory_p) read_etc_group(); for (int i = 0; i < curr_lines; i++) if (strcasematch (group_buf[i].gr_name, name)) return group_buf + i; /* Didn't find requested group */ return NULL; } extern "C" void endgrent() { grp_pos = 0; } extern "C" struct group * getgrent() { if (!group_in_memory_p) read_etc_group(); if (grp_pos < curr_lines) return group_buf + grp_pos++; return NULL; } extern "C" void setgrent () { grp_pos = 0; } int getgroups (int gidsetsize, gid_t *grouplist, gid_t gid, const char *username) { HANDLE hToken = NULL; char buf[4096]; DWORD size; int cnt = 0; if (!group_in_memory_p) read_etc_group(); if (allow_ntsec && OpenProcessToken (hMainProc, TOKEN_QUERY, &hToken) && GetTokenInformation (hToken, TokenGroups, buf, 4096, &size)) { TOKEN_GROUPS *groups = (TOKEN_GROUPS *) buf; char ssid[256]; for (DWORD pg = 0; pg < groups->GroupCount; ++pg) { convert_sid_to_string_sid (groups->Groups[pg].Sid, ssid); for (int gg = 0; gg < curr_lines; ++gg) { if (!strcmp (group_buf[gg].gr_passwd, ssid)) { if (cnt < gidsetsize) grouplist[cnt] = group_buf[gg].gr_gid; ++cnt; if (gidsetsize && cnt > gidsetsize) goto error; break; } } } CloseHandle (hToken); return cnt; } else { for (int i = 0; i < curr_lines; ++i) if (gid == group_buf[i].gr_gid) { if (cnt < gidsetsize) grouplist[cnt] = group_buf[i].gr_gid; ++cnt; if (gidsetsize && cnt > gidsetsize) goto error; } else if (group_buf[i].gr_mem) for (int gi = 0; group_buf[i].gr_mem[gi]; ++gi) if (strcasematch (username, group_buf[i].gr_mem[gi])) { if (cnt < gidsetsize) grouplist[cnt] = group_buf[i].gr_gid; ++cnt; if (gidsetsize && cnt > gidsetsize) goto error; } return cnt; } error: set_errno (EINVAL); return -1; } extern "C" int getgroups (int gidsetsize, gid_t *grouplist) { return getgroups (gidsetsize, grouplist, myself->gid, cygheap->user.name ()); } extern "C" int initgroups (const char *, gid_t) { return 0; }