diff options
Diffstat (limited to 'src/userinfo.c')
| -rw-r--r-- | src/userinfo.c | 177 |
1 files changed, 177 insertions, 0 deletions
diff --git a/src/userinfo.c b/src/userinfo.c new file mode 100644 index 0000000..df0b6e6 --- /dev/null +++ b/src/userinfo.c @@ -0,0 +1,177 @@ +/* + Copyright 2006,2007,2008 Martin Pärtel <martin.partel@gmail.com> + + This file is part of bindfs. + + bindfs is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 2 of the License, or + (at your option) any later version. + + bindfs is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with bindfs. If not, see <http://www.gnu.org/licenses/>. +*/ + +#include "userinfo.h" +#include <stdlib.h> +#include <string.h> +#include <errno.h> + + +int user_uid(const char *username, uid_t *ret) +{ + struct passwd pwbuf, *pwbufp = NULL; + char *buf; + size_t buflen; + int res; + + uid_t uid; + char *endptr; + + /* Check whether the string is a numerical UID */ + uid = strtol(username, &endptr, 10); + if (*endptr == '\0') { + buflen = 1024; + buf = malloc(buflen); + res = getpwuid_r(uid, &pwbuf, buf, buflen, &pwbufp); + if (res != 0) { + if (res != ERANGE) { /* don't care if buffer was too small */ + free(buf); + return 0; + } + } + free(buf); + *ret = uid; + return 1; + } + + /* Process user name */ + buflen = 1024; + buf = malloc(buflen); + + res = getpwnam_r(username, &pwbuf, buf, buflen, &pwbufp); + while(res == ERANGE) { + buflen *= 2; + buf = realloc(buf, buflen); + res = getpwnam_r(username, &pwbuf, buf, buflen, &pwbufp); + } + + if (pwbufp == NULL) { + free(buf); + return 0; + } + + *ret = pwbuf.pw_uid; + free(buf); + return 1; +} + + +int group_gid(const char *groupname, gid_t *ret) +{ + struct group gbuf, *gbufp = NULL; + char *buf; + size_t buflen; + int res; + + gid_t gid; + char *endptr; + + /* Check whether the string is a numerical GID */ + gid = strtol(groupname, &endptr, 10); + if (*endptr == '\0') { + buflen = 1024; + buf = malloc(buflen); + res = getgrgid_r(gid, &gbuf, buf, buflen, &gbufp); + if (res != 0) { + if (res != ERANGE) { /* don't care if buffer was too small */ + free(buf); + return 0; + } + } + free(buf); + *ret = gid; + return 1; + } + + /* Process group name */ + buflen = 1024; + buf = malloc(buflen); + + res = getgrnam_r(groupname, &gbuf, buf, buflen, &gbufp); + while(res == ERANGE) { + buflen *= 2; + buf = realloc(buf, buflen); + res = getgrnam_r(groupname, &gbuf, buf, buflen, &gbufp); + } + + if (gbufp == NULL) { + free(buf); + return 0; + } + + *ret = gbuf.gr_gid; + free(buf); + return 1; +} + + +int user_belongs_to_group(uid_t uid, gid_t gid) +{ + struct passwd pwbuf, *pwbufp = NULL; + struct group grbuf, *grbufp = NULL; + char *buf; + size_t buflen; + + int member; + uid_t member_uid; + + int res; + + buflen = 1024; + buf = malloc(buflen); + + res = getpwuid_r(uid, &pwbuf, buf, buflen, &pwbufp); + while(res == ERANGE) { + buflen *= 2; + buf = realloc(buf, buflen); + res = getpwuid_r(uid, &pwbuf, buf, buflen, &pwbufp); + } + + if (pwbufp == NULL) + goto no; + + if (gid == pwbuf.pw_gid) + goto yes; + + /* we reuse the same buf because we don't need the passwd info any more */ + res = getgrgid_r(gid, &grbuf, buf, buflen, &grbufp); + while(res == ERANGE) { + buflen *= 2; + buf = realloc(buf, buflen); + res = getgrgid_r(gid, &grbuf, buf, buflen, &grbufp); + } + + if (grbufp == NULL) + goto no; + + for (member = 0; grbuf.gr_mem[member] != NULL; ++member) { + if (user_uid(grbuf.gr_mem[member], &member_uid)) + if (member_uid == uid) + goto yes; + } + + goto no; + +yes: + free(buf); + return 1; +no: + free(buf); + return 0; +} |