diff options
Diffstat (limited to 'nss/nss_compat/compat-grp.c')
| -rw-r--r-- | nss/nss_compat/compat-grp.c | 682 |
1 files changed, 682 insertions, 0 deletions
diff --git a/nss/nss_compat/compat-grp.c b/nss/nss_compat/compat-grp.c new file mode 100644 index 0000000000..4d51fc95ed --- /dev/null +++ b/nss/nss_compat/compat-grp.c @@ -0,0 +1,682 @@ +/* Copyright (C) 1996-2017 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Thorsten Kukuk <kukuk@suse.de>, 1996. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library 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 + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <http://www.gnu.org/licenses/>. */ + +#include <ctype.h> +#include <errno.h> +#include <fcntl.h> +#include <grp.h> +#include <nss.h> +#include <nsswitch.h> +#include <stdio_ext.h> +#include <string.h> +#include <libc-lock.h> +#include <kernel-features.h> + +static service_user *ni; +static enum nss_status (*nss_setgrent) (int stayopen); +static enum nss_status (*nss_getgrnam_r) (const char *name, + struct group * grp, char *buffer, + size_t buflen, int *errnop); +static enum nss_status (*nss_getgrgid_r) (gid_t gid, struct group * grp, + char *buffer, size_t buflen, + int *errnop); +static enum nss_status (*nss_getgrent_r) (struct group * grp, char *buffer, + size_t buflen, int *errnop); +static enum nss_status (*nss_endgrent) (void); + +/* Get the declaration of the parser function. */ +#define ENTNAME grent +#define STRUCTURE group +#define EXTERN_PARSER +#include <nss/nss_files/files-parse.c> + +/* Structure for remembering -group members ... */ +#define BLACKLIST_INITIAL_SIZE 512 +#define BLACKLIST_INCREMENT 256 +struct blacklist_t +{ + char *data; + int current; + int size; +}; + +struct ent_t +{ + bool files; + enum nss_status setent_status; + FILE *stream; + struct blacklist_t blacklist; +}; +typedef struct ent_t ent_t; + +static ent_t ext_ent = { true, NSS_STATUS_SUCCESS, NULL, { NULL, 0, 0 }}; + +/* Protect global state against multiple changers. */ +__libc_lock_define_initialized (static, lock) + +/* Prototypes for local functions. */ +static void blacklist_store_name (const char *, ent_t *); +static bool in_blacklist (const char *, int, ent_t *); + +/* Initialize the NSS interface/functions. The calling function must + hold the lock. */ +static void +init_nss_interface (void) +{ + if (__nss_database_lookup ("group_compat", NULL, "nis", &ni) >= 0) + { + nss_setgrent = __nss_lookup_function (ni, "setgrent"); + nss_getgrnam_r = __nss_lookup_function (ni, "getgrnam_r"); + nss_getgrgid_r = __nss_lookup_function (ni, "getgrgid_r"); + nss_getgrent_r = __nss_lookup_function (ni, "getgrent_r"); + nss_endgrent = __nss_lookup_function (ni, "endgrent"); + } +} + +static enum nss_status +internal_setgrent (ent_t *ent, int stayopen, int needent) +{ + enum nss_status status = NSS_STATUS_SUCCESS; + + ent->files = true; + + if (ent->blacklist.data != NULL) + { + ent->blacklist.current = 1; + ent->blacklist.data[0] = '|'; + ent->blacklist.data[1] = '\0'; + } + else + ent->blacklist.current = 0; + + if (ent->stream == NULL) + { + ent->stream = fopen ("/etc/group", "rme"); + + if (ent->stream == NULL) + status = errno == EAGAIN ? NSS_STATUS_TRYAGAIN : NSS_STATUS_UNAVAIL; + else + /* We take care of locking ourself. */ + __fsetlocking (ent->stream, FSETLOCKING_BYCALLER); + } + else + rewind (ent->stream); + + if (needent && status == NSS_STATUS_SUCCESS && nss_setgrent) + ent->setent_status = nss_setgrent (stayopen); + + return status; +} + + +enum nss_status +_nss_compat_setgrent (int stayopen) +{ + enum nss_status result; + + __libc_lock_lock (lock); + + if (ni == NULL) + init_nss_interface (); + + result = internal_setgrent (&ext_ent, stayopen, 1); + + __libc_lock_unlock (lock); + + return result; +} + + +static enum nss_status +internal_endgrent (ent_t *ent) +{ + if (ent->stream != NULL) + { + fclose (ent->stream); + ent->stream = NULL; + } + + if (ent->blacklist.data != NULL) + { + ent->blacklist.current = 1; + ent->blacklist.data[0] = '|'; + ent->blacklist.data[1] = '\0'; + } + else + ent->blacklist.current = 0; + + return NSS_STATUS_SUCCESS; +} + +enum nss_status +_nss_compat_endgrent (void) +{ + enum nss_status result; + + __libc_lock_lock (lock); + + if (nss_endgrent) + nss_endgrent (); + + result = internal_endgrent (&ext_ent); + + __libc_lock_unlock (lock); + + return result; +} + +/* get the next group from NSS (+ entry) */ +static enum nss_status +getgrent_next_nss (struct group *result, ent_t *ent, char *buffer, + size_t buflen, int *errnop) +{ + if (!nss_getgrent_r) + return NSS_STATUS_UNAVAIL; + + /* If the setgrent call failed, say so. */ + if (ent->setent_status != NSS_STATUS_SUCCESS) + return ent->setent_status; + + do + { + enum nss_status status; + + if ((status = nss_getgrent_r (result, buffer, buflen, errnop)) != + NSS_STATUS_SUCCESS) + return status; + } + while (in_blacklist (result->gr_name, strlen (result->gr_name), ent)); + + return NSS_STATUS_SUCCESS; +} + +/* This function handle the +group entrys in /etc/group */ +static enum nss_status +getgrnam_plusgroup (const char *name, struct group *result, ent_t *ent, + char *buffer, size_t buflen, int *errnop) +{ + if (!nss_getgrnam_r) + return NSS_STATUS_UNAVAIL; + + enum nss_status status = nss_getgrnam_r (name, result, buffer, buflen, + errnop); + if (status != NSS_STATUS_SUCCESS) + return status; + + if (in_blacklist (result->gr_name, strlen (result->gr_name), ent)) + return NSS_STATUS_NOTFOUND; + + /* We found the entry. */ + return NSS_STATUS_SUCCESS; +} + +static enum nss_status +getgrent_next_file (struct group *result, ent_t *ent, + char *buffer, size_t buflen, int *errnop) +{ + struct parser_data *data = (void *) buffer; + while (1) + { + fpos_t pos; + int parse_res = 0; + char *p; + + do + { + /* We need at least 3 characters for one line. */ + if (__glibc_unlikely (buflen < 3)) + { + erange: + *errnop = ERANGE; + return NSS_STATUS_TRYAGAIN; + } + + fgetpos (ent->stream, &pos); + buffer[buflen - 1] = '\xff'; + p = fgets_unlocked (buffer, buflen, ent->stream); + if (p == NULL && feof_unlocked (ent->stream)) + return NSS_STATUS_NOTFOUND; + + if (p == NULL || __builtin_expect (buffer[buflen - 1] != '\xff', 0)) + { + erange_reset: + fsetpos (ent->stream, &pos); + goto erange; + } + + /* Terminate the line for any case. */ + buffer[buflen - 1] = '\0'; + + /* Skip leading blanks. */ + while (isspace (*p)) + ++p; + } + while (*p == '\0' || *p == '#' || /* Ignore empty and comment lines. */ + /* Parse the line. If it is invalid, loop to + get the next line of the file to parse. */ + !(parse_res = _nss_files_parse_grent (p, result, data, buflen, + errnop))); + + if (__glibc_unlikely (parse_res == -1)) + /* The parser ran out of space. */ + goto erange_reset; + + if (result->gr_name[0] != '+' && result->gr_name[0] != '-') + /* This is a real entry. */ + break; + + /* -group */ + if (result->gr_name[0] == '-' && result->gr_name[1] != '\0' + && result->gr_name[1] != '@') + { + blacklist_store_name (&result->gr_name[1], ent); + continue; + } + + /* +group */ + if (result->gr_name[0] == '+' && result->gr_name[1] != '\0' + && result->gr_name[1] != '@') + { + size_t len = strlen (result->gr_name); + char buf[len]; + enum nss_status status; + + /* Store the group in the blacklist for the "+" at the end of + /etc/group */ + memcpy (buf, &result->gr_name[1], len); + status = getgrnam_plusgroup (&result->gr_name[1], result, ent, + buffer, buflen, errnop); + blacklist_store_name (buf, ent); + if (status == NSS_STATUS_SUCCESS) /* We found the entry. */ + break; + else if (status == NSS_STATUS_RETURN /* We couldn't parse the entry*/ + || status == NSS_STATUS_NOTFOUND) /* No group in NIS */ + continue; + else + { + if (status == NSS_STATUS_TRYAGAIN) + /* The parser ran out of space. */ + goto erange_reset; + + return status; + } + } + + /* +:... */ + if (result->gr_name[0] == '+' && result->gr_name[1] == '\0') + { + ent->files = false; + + return getgrent_next_nss (result, ent, buffer, buflen, errnop); + } + } + + return NSS_STATUS_SUCCESS; +} + + +enum nss_status +_nss_compat_getgrent_r (struct group *grp, char *buffer, size_t buflen, + int *errnop) +{ + enum nss_status result = NSS_STATUS_SUCCESS; + + __libc_lock_lock (lock); + + /* Be prepared that the setgrent function was not called before. */ + if (ni == NULL) + init_nss_interface (); + + if (ext_ent.stream == NULL) + result = internal_setgrent (&ext_ent, 1, 1); + + if (result == NSS_STATUS_SUCCESS) + { + if (ext_ent.files) + result = getgrent_next_file (grp, &ext_ent, buffer, buflen, errnop); + else + result = getgrent_next_nss (grp, &ext_ent, buffer, buflen, errnop); + } + __libc_lock_unlock (lock); + + return result; +} + +/* Searches in /etc/group and the NIS/NIS+ map for a special group */ +static enum nss_status +internal_getgrnam_r (const char *name, struct group *result, ent_t *ent, + char *buffer, size_t buflen, int *errnop) +{ + struct parser_data *data = (void *) buffer; + while (1) + { + fpos_t pos; + int parse_res = 0; + char *p; + + do + { + /* We need at least 3 characters for one line. */ + if (__glibc_unlikely (buflen < 3)) + { + erange: + *errnop = ERANGE; + return NSS_STATUS_TRYAGAIN; + } + + fgetpos (ent->stream, &pos); + buffer[buflen - 1] = '\xff'; + p = fgets_unlocked (buffer, buflen, ent->stream); + if (p == NULL && feof_unlocked (ent->stream)) + return NSS_STATUS_NOTFOUND; + + if (p == NULL || __builtin_expect (buffer[buflen - 1] != '\xff', 0)) + { + erange_reset: + fsetpos (ent->stream, &pos); + goto erange; + } + + /* Terminate the line for any case. */ + buffer[buflen - 1] = '\0'; + + /* Skip leading blanks. */ + while (isspace (*p)) + ++p; + } + while (*p == '\0' || *p == '#' || /* Ignore empty and comment lines. */ + /* Parse the line. If it is invalid, loop to + get the next line of the file to parse. */ + !(parse_res = _nss_files_parse_grent (p, result, data, buflen, + errnop))); + + if (__glibc_unlikely (parse_res == -1)) + /* The parser ran out of space. */ + goto erange_reset; + + /* This is a real entry. */ + if (result->gr_name[0] != '+' && result->gr_name[0] != '-') + { + if (strcmp (result->gr_name, name) == 0) + return NSS_STATUS_SUCCESS; + else + continue; + } + + /* -group */ + if (result->gr_name[0] == '-' && result->gr_name[1] != '\0') + { + if (strcmp (&result->gr_name[1], name) == 0) + return NSS_STATUS_NOTFOUND; + else + continue; + } + + /* +group */ + if (result->gr_name[0] == '+' && result->gr_name[1] != '\0') + { + if (strcmp (name, &result->gr_name[1]) == 0) + { + enum nss_status status; + + status = getgrnam_plusgroup (name, result, ent, + buffer, buflen, errnop); + if (status == NSS_STATUS_RETURN) + /* We couldn't parse the entry */ + continue; + else + return status; + } + } + /* +:... */ + if (result->gr_name[0] == '+' && result->gr_name[1] == '\0') + { + enum nss_status status; + + status = getgrnam_plusgroup (name, result, ent, + buffer, buflen, errnop); + if (status == NSS_STATUS_RETURN) + /* We couldn't parse the entry */ + continue; + else + return status; + } + } + + return NSS_STATUS_SUCCESS; +} + +enum nss_status +_nss_compat_getgrnam_r (const char *name, struct group *grp, + char *buffer, size_t buflen, int *errnop) +{ + ent_t ent = { true, NSS_STATUS_SUCCESS, NULL, { NULL, 0, 0 }}; + enum nss_status result; + + if (name[0] == '-' || name[0] == '+') + return NSS_STATUS_NOTFOUND; + + __libc_lock_lock (lock); + + if (ni == NULL) + init_nss_interface (); + + __libc_lock_unlock (lock); + + result = internal_setgrent (&ent, 0, 0); + + if (result == NSS_STATUS_SUCCESS) + result = internal_getgrnam_r (name, grp, &ent, buffer, buflen, errnop); + + internal_endgrent (&ent); + + return result; +} + +/* Searches in /etc/group and the NIS/NIS+ map for a special group id */ +static enum nss_status +internal_getgrgid_r (gid_t gid, struct group *result, ent_t *ent, + char *buffer, size_t buflen, int *errnop) +{ + struct parser_data *data = (void *) buffer; + while (1) + { + fpos_t pos; + int parse_res = 0; + char *p; + + do + { + /* We need at least 3 characters for one line. */ + if (__glibc_unlikely (buflen < 3)) + { + erange: + *errnop = ERANGE; + return NSS_STATUS_TRYAGAIN; + } + + fgetpos (ent->stream, &pos); + buffer[buflen - 1] = '\xff'; + p = fgets_unlocked (buffer, buflen, ent->stream); + if (p == NULL && feof_unlocked (ent->stream)) + return NSS_STATUS_NOTFOUND; + + if (p == NULL || __builtin_expect (buffer[buflen - 1] != '\xff', 0)) + { + erange_reset: + fsetpos (ent->stream, &pos); + goto erange; + } + + /* Terminate the line for any case. */ + buffer[buflen - 1] = '\0'; + + /* Skip leading blanks. */ + while (isspace (*p)) + ++p; + } + while (*p == '\0' || *p == '#' || /* Ignore empty and comment lines. */ + /* Parse the line. If it is invalid, loop to + get the next line of the file to parse. */ + !(parse_res = _nss_files_parse_grent (p, result, data, buflen, + errnop))); + + if (__glibc_unlikely (parse_res == -1)) + /* The parser ran out of space. */ + goto erange_reset; + + /* This is a real entry. */ + if (result->gr_name[0] != '+' && result->gr_name[0] != '-') + { + if (result->gr_gid == gid) + return NSS_STATUS_SUCCESS; + else + continue; + } + + /* -group */ + if (result->gr_name[0] == '-' && result->gr_name[1] != '\0') + { + blacklist_store_name (&result->gr_name[1], ent); + continue; + } + + /* +group */ + if (result->gr_name[0] == '+' && result->gr_name[1] != '\0') + { + /* Yes, no +1, see the memcpy call below. */ + size_t len = strlen (result->gr_name); + char buf[len]; + enum nss_status status; + + /* Store the group in the blacklist for the "+" at the end of + /etc/group */ + memcpy (buf, &result->gr_name[1], len); + status = getgrnam_plusgroup (&result->gr_name[1], result, ent, + buffer, buflen, errnop); + blacklist_store_name (buf, ent); + if (status == NSS_STATUS_SUCCESS && result->gr_gid == gid) + break; + else + continue; + } + /* +:... */ + if (result->gr_name[0] == '+' && result->gr_name[1] == '\0') + { + if (!nss_getgrgid_r) + return NSS_STATUS_UNAVAIL; + + enum nss_status status = nss_getgrgid_r (gid, result, buffer, buflen, + errnop); + if (status == NSS_STATUS_RETURN) /* We couldn't parse the entry */ + return NSS_STATUS_NOTFOUND; + else + return status; + } + } + + return NSS_STATUS_SUCCESS; +} + +enum nss_status +_nss_compat_getgrgid_r (gid_t gid, struct group *grp, + char *buffer, size_t buflen, int *errnop) +{ + ent_t ent = { true, NSS_STATUS_SUCCESS, NULL, { NULL, 0, 0 }}; + enum nss_status result; + + __libc_lock_lock (lock); + + if (ni == NULL) + init_nss_interface (); + + __libc_lock_unlock (lock); + + result = internal_setgrent (&ent, 0, 0); + + if (result == NSS_STATUS_SUCCESS) + result = internal_getgrgid_r (gid, grp, &ent, buffer, buflen, errnop); + + internal_endgrent (&ent); + + return result; +} + + +/* Support routines for remembering -@netgroup and -user entries. + The names are stored in a single string with `|' as separator. */ +static void +blacklist_store_name (const char *name, ent_t *ent) +{ + int namelen = strlen (name); + char *tmp; + + /* first call, setup cache */ + if (ent->blacklist.size == 0) + { + ent->blacklist.size = MAX (BLACKLIST_INITIAL_SIZE, 2 * namelen); + ent->blacklist.data = malloc (ent->blacklist.size); + if (ent->blacklist.data == NULL) + return; + ent->blacklist.data[0] = '|'; + ent->blacklist.data[1] = '\0'; + ent->blacklist.current = 1; + } + else + { + if (in_blacklist (name, namelen, ent)) + return; /* no duplicates */ + + if (ent->blacklist.current + namelen + 1 >= ent->blacklist.size) + { + ent->blacklist.size += MAX (BLACKLIST_INCREMENT, 2 * namelen); + tmp = realloc (ent->blacklist.data, ent->blacklist.size); + if (tmp == NULL) + { + free (ent->blacklist.data); + ent->blacklist.size = 0; + return; + } + ent->blacklist.data = tmp; + } + } + + tmp = stpcpy (ent->blacklist.data + ent->blacklist.current, name); + *tmp++ = '|'; + *tmp = '\0'; + ent->blacklist.current += namelen + 1; + + return; +} + +/* Return whether ent->blacklist contains name. */ +static bool +in_blacklist (const char *name, int namelen, ent_t *ent) +{ + char buf[namelen + 3]; + char *cp; + + if (ent->blacklist.data == NULL) + return false; + + buf[0] = '|'; + cp = stpcpy (&buf[1], name); + *cp++ = '|'; + *cp = '\0'; + return strstr (ent->blacklist.data, buf) != NULL; +} |