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Diffstat (limited to 'nss/nss_files/files-alias.c')
-rw-r--r--nss/nss_files/files-alias.c424
1 files changed, 424 insertions, 0 deletions
diff --git a/nss/nss_files/files-alias.c b/nss/nss_files/files-alias.c
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index 0000000000..c6ef49c621
--- /dev/null
+++ b/nss/nss_files/files-alias.c
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+/* Mail alias file parser in nss_files module.
+ Copyright (C) 1996 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+ Contributed by Ulrich Drepper <drepper@cygnus.com>, 1996.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Library General Public License as
+ published by the Free Software Foundation; either version 2 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
+ Library General Public License for more details.
+
+ You should have received a copy of the GNU Library General Public
+ License along with the GNU C Library; see the file COPYING.LIB. If not,
+ write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ Boston, MA 02111-1307, USA. */
+
+#include <aliases.h>
+#include <ctype.h>
+#include <libc-lock.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+
+#include "nsswitch.h"
+
+/* Locks the static variables in this file. */
+__libc_lock_define_initialized (static, lock)
+
+/* Maintenance of the shared stream open on the database file. */
+
+static FILE *stream;
+static fpos_t position;
+static enum { none, getent, getby } last_use;
+
+
+static enum nss_status
+internal_setent (void)
+{
+ enum nss_status status = NSS_STATUS_SUCCESS;
+
+ if (stream == NULL)
+ {
+ stream = fopen ("/etc/aliases", "r");
+
+ if (stream == NULL)
+ status = NSS_STATUS_UNAVAIL;
+ }
+ else
+ rewind (stream);
+
+ return status;
+}
+
+
+/* Thread-safe, exported version of that. */
+enum nss_status
+_nss_files_setaliasent (void)
+{
+ enum nss_status status;
+
+ __libc_lock_lock (lock);
+
+ status = internal_setent ();
+
+ if (status == NSS_STATUS_SUCCESS && fgetpos (stream, &position) < 0)
+ {
+ fclose (stream);
+ stream = NULL;
+ status = NSS_STATUS_UNAVAIL;
+ }
+
+ last_use = getent;
+
+ __libc_lock_unlock (lock);
+
+ return status;
+}
+
+
+/* Close the database file. */
+static void
+internal_endent (void)
+{
+ if (stream != NULL)
+ {
+ fclose (stream);
+ stream = NULL;
+ }
+}
+
+
+/* Thread-safe, exported version of that. */
+enum nss_status
+_nss_files_endaliasent (void)
+{
+ __libc_lock_lock (lock);
+
+ internal_endent ();
+
+ __libc_lock_unlock (lock);
+
+ return NSS_STATUS_SUCCESS;
+}
+
+/* Parsing the database file into `struct aliasent' data structures. */
+static enum nss_status
+get_next_alias (const char *match, struct aliasent *result,
+ char *buffer, size_t buflen)
+{
+ enum nss_status status = NSS_STATUS_NOTFOUND;
+ int ignore = 0;
+
+ result->alias_members_len = 0;
+
+ while (1)
+ {
+ /* Now we are ready to process the input. We have to read a
+ line and all its continuations and construct the array of
+ string pointers. This pointers and the names itself have to
+ be placed in BUFFER. */
+ char *first_unused = buffer;
+ size_t room_left = buflen - (buflen % __alignof__ (char *));
+ char *line;
+
+ /* Read the first line. It must contain the alias name and
+ possibly some alias names. */
+ first_unused[room_left - 1] = '\0';
+ line = fgets (first_unused, room_left, stream);
+ if (line == NULL)
+ /* Nothing to read. */
+ break;
+ else if (first_unused[room_left - 1] != '\0')
+ {
+ /* The line is too long for our buffer. */
+ no_more_room:
+ __set_errno (ERANGE);
+ status = NSS_STATUS_TRYAGAIN;
+ break;
+ }
+ else
+ {
+ char *cp;
+
+ /* If we are in IGNORE mode and the first character in the
+ line is a white space we ignore the line and start
+ reading the next. */
+ if (ignore && isspace (first_unused))
+ continue;
+
+ /* Terminate the line for any case. */
+ cp = strpbrk (first_unused, "#\n");
+ if (cp != NULL)
+ *cp = '\0';
+
+ /* Skip leading blanks. */
+ while (isspace (*line))
+ ++line;
+
+ result->alias_name = first_unused;
+ while (*line != '\0' && *line != ':')
+ *first_unused++ = *line++;
+ if (*line == '\0' || result->alias_name == first_unused)
+ /* No valid name. Ignore the line. */
+ continue;
+
+ *first_unused++ = '\0';
+ if (room_left < (size_t) (first_unused - result->alias_name))
+ goto no_more_room;
+ room_left -= first_unused - result->alias_name;
+ ++line;
+
+ /* When we search for a specific alias we can avoid all the
+ difficult parts and compare now with the name we are
+ looking for. If it does not match we simply ignore all
+ lines until the next line containing the start of a new
+ alias is found. */
+ ignore = match != NULL && strcmp (result->alias_name, match) == 0;
+
+ while (! ignore)
+ {
+ while (isspace (*line))
+ ++line;
+
+ cp = first_unused;
+ while (*line != '\0' && *line != ',')
+ *first_unused++ = *line++;
+
+ if (first_unused != cp)
+ {
+ if (*line != '\0')
+ {
+ /* OK, we can have a regular entry or an include
+ request. */
+ *first_unused++ = '\0';
+ ++line;
+ }
+ else
+ ++first_unused;
+
+
+ if (strncmp (cp, ":include:", 9) != 0)
+ {
+ if (room_left < (first_unused - cp) + sizeof (char *))
+ goto no_more_room;
+ room_left -= (first_unused - cp) + sizeof (char *);
+
+ ++result->alias_members_len;
+ }
+ else
+ {
+ /* Oh well, we have to read the addressed file. */
+ FILE *listfile;
+ char *old_line = NULL;
+
+ first_unused = cp;
+
+ listfile = fopen (&cp[9], "r");
+ /* If the file does not exist we simply ignore
+ the statement. */
+ if (listfile != NULL
+ && (old_line = strdup (line)) != NULL)
+ {
+ while (! feof (listfile))
+ {
+ first_unused[room_left - 1] = '\0';
+ line = fgets (first_unused, room_left, listfile);
+ if (line == NULL)
+ break;
+ if (first_unused[room_left - 1] != '\0')
+ {
+ free (old_line);
+ goto no_more_room;
+ }
+
+ /* Parse the line. */
+ cp = strpbrk (line, "#\n");
+ if (cp != NULL)
+ *cp = '\0';
+
+ do
+ {
+ while (isspace (*line))
+ ++line;
+
+ cp = first_unused;
+ while (*line != '\0' && *line != ',')
+ *first_unused++ = *line++;
+
+ if (*line != '\0')
+ ++line;
+
+ if (first_unused != cp)
+ {
+ *first_unused++ = '\0';
+ if (room_left < ((first_unused - cp)
+ + __alignof__ (char *)))
+ {
+ free (old_line);
+ goto no_more_room;
+ }
+ room_left -= ((first_unused - cp)
+ + __alignof__ (char *));
+ ++result->alias_members_len;
+ }
+ }
+ while (*line != '\0');
+ }
+ fclose (listfile);
+
+ first_unused[room_left - 1] = '\0';
+ strncpy (first_unused, old_line, room_left);
+
+ if (old_line != NULL)
+ free (old_line);
+
+ if (first_unused[room_left - 1] != '\0')
+ goto no_more_room;
+ }
+ }
+ }
+
+ if (*line == '\0')
+ {
+ /* Get the next line. But we must be careful. We
+ must not read the whole line at once since it
+ might belong to the current alias. Simply read
+ the first character. If it is a white space we
+ have a continuation line. Otherwise it is the
+ beginning of a new alias and we can push back the
+ just read character. */
+ int ch;
+
+ first_unused[room_left - 1] = '\0';
+ line = first_unused;
+ ch = fgetc (stream);
+ if (ch == EOF || !isspace (ch))
+ {
+ size_t cnt;
+
+ /* Now prepare the return. Provide string
+ pointers for the currently selected aliases. */
+ if (ch != EOF)
+ ungetc (ch, stream);
+
+ /* Adjust the pointer so it is aligned for
+ storing pointers. */
+ first_unused += __alignof__ (char *) - 1;
+ first_unused -= ((first_unused - (char *) 0)
+ % __alignof__ (char *));
+ result->alias_members = (char **) first_unused;
+
+ /* Compute addresses of alias entry strings. */
+ cp = result->alias_name;
+ for (cnt = 0; cnt < result->alias_members_len; ++cnt)
+ {
+ cp = strchr (cp, '\0') + 1;
+ result->alias_members[cnt] = cp;
+ }
+
+ status = (result->alias_members_len == 0
+ ? NSS_STATUS_RETURN : NSS_STATUS_SUCCESS);
+ break;
+ }
+
+ /* The just read character is a white space and so
+ can be ignored. */
+ cp = strpbrk (line, "#\n");
+ if (cp != NULL)
+ *cp = '\0';
+ }
+ }
+ }
+
+ if (status != NSS_STATUS_NOTFOUND)
+ /* We read something. In any case break here. */
+ break;
+ }
+
+ return status;
+}
+
+
+enum nss_status
+_nss_files_getaliasent_r (struct aliasent *result, char *buffer, size_t buflen)
+{
+ /* Return next entry in host file. */
+ enum nss_status status = NSS_STATUS_SUCCESS;
+
+ __libc_lock_lock (lock);
+
+ /* Be prepared that the set*ent function was not called before. */
+ if (stream == NULL)
+ status = internal_setent ();
+
+ if (status == NSS_STATUS_SUCCESS)
+ {
+ /* If the last use was not by the getent function we need the
+ position the stream. */
+ if (last_use != getent)
+ if (fsetpos (stream, &position) < 0)
+ status = NSS_STATUS_UNAVAIL;
+ else
+ last_use = getent;
+
+ if (status == NSS_STATUS_SUCCESS)
+ {
+ result->alias_local = 1;
+
+ /* Read lines until we get a definite result. */
+ do
+ status = get_next_alias (NULL, result, buffer, buflen);
+ while (status == NSS_STATUS_RETURN);
+
+ /* If we successfully read an entry remember this position. */
+ if (status == NSS_STATUS_SUCCESS)
+ fgetpos (stream, &position);
+ else
+ last_use = none;
+ }
+ }
+
+ __libc_lock_unlock (lock);
+
+ return status;
+}
+
+
+enum nss_status
+_nss_files_getaliasbyname_r (const char *name, struct aliasent *result,
+ char *buffer, size_t buflen)
+{
+ /* Return next entry in host file. */
+ enum nss_status status = NSS_STATUS_SUCCESS;
+
+ if (name == NULL)
+ {
+ __set_errno (EINVAL);
+ return NSS_STATUS_UNAVAIL;
+ }
+
+ __libc_lock_lock (lock);
+
+ /* Open the stream or rest it. */
+ status = internal_setent ();
+ last_use = getby;
+
+ if (status == NSS_STATUS_SUCCESS)
+ {
+ result->alias_local = 1;
+
+ /* Read lines until we get a definite result. */
+ do
+ status = get_next_alias (name, result, buffer, buflen);
+ while (status == NSS_STATUS_RETURN);
+ }
+
+ __libc_lock_unlock (lock);
+
+ return status;
+}
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