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-rw-r--r--lib/commonio.c1276
1 files changed, 1276 insertions, 0 deletions
diff --git a/lib/commonio.c b/lib/commonio.c
new file mode 100644
index 0000000..9a02ce1
--- /dev/null
+++ b/lib/commonio.c
@@ -0,0 +1,1276 @@
+/*
+ * SPDX-FileCopyrightText: 1990 - 1994, Julianne Frances Haugh
+ * SPDX-FileCopyrightText: 1996 - 2001, Marek Michałkiewicz
+ * SPDX-FileCopyrightText: 2001 - 2006, Tomasz Kłoczko
+ * SPDX-FileCopyrightText: 2007 - 2011, Nicolas François
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <config.h>
+
+#ident "$Id$"
+
+#include "defines.h"
+#include <assert.h>
+#include <sys/stat.h>
+#include <stdlib.h>
+#include <limits.h>
+#include <utime.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <stdio.h>
+#include <signal.h>
+#include "nscd.h"
+#include "sssd.h"
+#ifdef WITH_TCB
+#include <tcb.h>
+#endif /* WITH_TCB */
+#include "prototypes.h"
+#include "commonio.h"
+#include "shadowlog_internal.h"
+
+/* local function prototypes */
+static int lrename (const char *, const char *);
+static int check_link_count (const char *file, bool log);
+static int do_lock_file (const char *file, const char *lock, bool log);
+static /*@null@*/ /*@dependent@*/FILE *fopen_set_perms (
+ const char *name,
+ const char *mode,
+ const struct stat *sb);
+static int create_backup (const char *, FILE *);
+static void free_linked_list (struct commonio_db *);
+static void add_one_entry (
+ struct commonio_db *db,
+ /*@owned@*/struct commonio_entry *p);
+static bool name_is_nis (const char *name);
+static int write_all (const struct commonio_db *);
+static /*@dependent@*/ /*@null@*/struct commonio_entry *find_entry_by_name (
+ struct commonio_db *,
+ const char *);
+static /*@dependent@*/ /*@null@*/struct commonio_entry *next_entry_by_name (
+ struct commonio_db *,
+ /*@null@*/struct commonio_entry *pos,
+ const char *);
+
+static int lock_count = 0;
+static bool nscd_need_reload = false;
+
+/*
+ * Simple rename(P) alternative that attempts to rename to symlink
+ * target.
+ */
+int lrename (const char *old, const char *new)
+{
+ int res;
+ char *r = NULL;
+
+#ifndef __GLIBC__
+ char resolved_path[PATH_MAX];
+#endif /* !__GLIBC__ */
+ struct stat sb;
+ if (lstat (new, &sb) == 0 && S_ISLNK (sb.st_mode)) {
+#ifdef __GLIBC__ /* now a POSIX.1-2008 feature */
+ r = realpath (new, NULL);
+#else /* !__GLIBC__ */
+ r = realpath (new, resolved_path);
+#endif /* !__GLIBC__ */
+ if (NULL == r) {
+ perror ("realpath in lrename()");
+ } else {
+ new = r;
+ }
+ }
+
+ res = rename (old, new);
+
+#ifdef __GLIBC__
+ free (r);
+#endif /* __GLIBC__ */
+
+ return res;
+}
+
+static int check_link_count (const char *file, bool log)
+{
+ struct stat sb;
+
+ if (stat (file, &sb) != 0) {
+ if (log) {
+ (void) fprintf (shadow_logfd,
+ "%s: %s file stat error: %s\n",
+ shadow_progname, file, strerror (errno));
+ }
+ return 0;
+ }
+
+ if (sb.st_nlink != 2) {
+ if (log) {
+ (void) fprintf (shadow_logfd,
+ "%s: %s: lock file already used (nlink: %u)\n",
+ shadow_progname, file, sb.st_nlink);
+ }
+ return 0;
+ }
+
+ return 1;
+}
+
+
+static int do_lock_file (const char *file, const char *lock, bool log)
+{
+ int fd;
+ pid_t pid;
+ ssize_t len;
+ int retval;
+ char buf[32];
+
+ fd = open (file, O_CREAT | O_TRUNC | O_WRONLY, 0600);
+ if (-1 == fd) {
+ if (log) {
+ (void) fprintf (shadow_logfd,
+ "%s: %s: %s\n",
+ shadow_progname, file, strerror (errno));
+ }
+ return 0;
+ }
+
+ pid = getpid ();
+ snprintf (buf, sizeof buf, "%lu", (unsigned long) pid);
+ len = (ssize_t) strlen (buf) + 1;
+ if (write (fd, buf, (size_t) len) != len) {
+ if (log) {
+ (void) fprintf (shadow_logfd,
+ "%s: %s file write error: %s\n",
+ shadow_progname, file, strerror (errno));
+ }
+ (void) close (fd);
+ unlink (file);
+ return 0;
+ }
+ if (fdatasync (fd) == -1) {
+ if (log) {
+ (void) fprintf (shadow_logfd,
+ "%s: %s file sync error: %s\n",
+ shadow_progname, file, strerror (errno));
+ }
+ (void) close (fd);
+ unlink (file);
+ return 0;
+ }
+ close (fd);
+
+ if (link (file, lock) == 0) {
+ retval = check_link_count (file, log);
+ unlink (file);
+ return retval;
+ }
+
+ fd = open (lock, O_RDWR);
+ if (-1 == fd) {
+ if (log) {
+ (void) fprintf (shadow_logfd,
+ "%s: %s: %s\n",
+ shadow_progname, lock, strerror (errno));
+ }
+ unlink (file);
+ errno = EINVAL;
+ return 0;
+ }
+ len = read (fd, buf, sizeof (buf) - 1);
+ close (fd);
+ if (len <= 0) {
+ if (log) {
+ (void) fprintf (shadow_logfd,
+ "%s: existing lock file %s without a PID\n",
+ shadow_progname, lock);
+ }
+ unlink (file);
+ errno = EINVAL;
+ return 0;
+ }
+ buf[len] = '\0';
+ if (get_pid (buf, &pid) == 0) {
+ if (log) {
+ (void) fprintf (shadow_logfd,
+ "%s: existing lock file %s with an invalid PID '%s'\n",
+ shadow_progname, lock, buf);
+ }
+ unlink (file);
+ errno = EINVAL;
+ return 0;
+ }
+ if (kill (pid, 0) == 0) {
+ if (log) {
+ (void) fprintf (shadow_logfd,
+ "%s: lock %s already used by PID %lu\n",
+ shadow_progname, lock, (unsigned long) pid);
+ }
+ unlink (file);
+ errno = EEXIST;
+ return 0;
+ }
+ if (unlink (lock) != 0) {
+ if (log) {
+ (void) fprintf (shadow_logfd,
+ "%s: cannot get lock %s: %s\n",
+ shadow_progname, lock, strerror (errno));
+ }
+ unlink (file);
+ return 0;
+ }
+
+ retval = 0;
+ if (link (file, lock) == 0) {
+ retval = check_link_count (file, log);
+ } else {
+ if (log) {
+ (void) fprintf (shadow_logfd,
+ "%s: cannot get lock %s: %s\n",
+ shadow_progname, lock, strerror (errno));
+ }
+ }
+
+ unlink (file);
+ return retval;
+}
+
+
+static /*@null@*/ /*@dependent@*/FILE *fopen_set_perms (
+ const char *name,
+ const char *mode,
+ const struct stat *sb)
+{
+ FILE *fp;
+ mode_t mask;
+
+ mask = umask (0777);
+ fp = fopen (name, mode);
+ (void) umask (mask);
+ if (NULL == fp) {
+ return NULL;
+ }
+
+#ifdef HAVE_FCHOWN
+ if (fchown (fileno (fp), sb->st_uid, sb->st_gid) != 0) {
+ goto fail;
+ }
+#else /* !HAVE_FCHOWN */
+ if (chown (name, sb->st_mode) != 0) {
+ goto fail;
+ }
+#endif /* !HAVE_FCHOWN */
+
+#ifdef HAVE_FCHMOD
+ if (fchmod (fileno (fp), sb->st_mode & 0664) != 0) {
+ goto fail;
+ }
+#else /* !HAVE_FCHMOD */
+ if (chmod (name, sb->st_mode & 0664) != 0) {
+ goto fail;
+ }
+#endif /* !HAVE_FCHMOD */
+ return fp;
+
+ fail:
+ (void) fclose (fp);
+ /* fopen_set_perms is used for intermediate files */
+ (void) unlink (name);
+ return NULL;
+}
+
+
+static int create_backup (const char *backup, FILE * fp)
+{
+ struct stat sb;
+ struct utimbuf ub;
+ FILE *bkfp;
+ int c;
+
+ if (fstat (fileno (fp), &sb) != 0) {
+ return -1;
+ }
+
+ bkfp = fopen_set_perms (backup, "w", &sb);
+ if (NULL == bkfp) {
+ return -1;
+ }
+
+ /* TODO: faster copy, not one-char-at-a-time. --marekm */
+ c = 0;
+ if (fseek (fp, 0, SEEK_SET) == 0) {
+ while ((c = getc (fp)) != EOF) {
+ if (putc (c, bkfp) == EOF) {
+ break;
+ }
+ }
+ }
+ if ((c != EOF) || (ferror (fp) != 0) || (fflush (bkfp) != 0)) {
+ (void) fclose (bkfp);
+ /* FIXME: unlink the backup file? */
+ return -1;
+ }
+ if (fsync (fileno (bkfp)) != 0) {
+ (void) fclose (bkfp);
+ /* FIXME: unlink the backup file? */
+ return -1;
+ }
+ if (fclose (bkfp) != 0) {
+ /* FIXME: unlink the backup file? */
+ return -1;
+ }
+
+ ub.actime = sb.st_atime;
+ ub.modtime = sb.st_mtime;
+ (void) utime (backup, &ub);
+ return 0;
+}
+
+
+static void free_linked_list (struct commonio_db *db)
+{
+ struct commonio_entry *p;
+
+ while (NULL != db->head) {
+ p = db->head;
+ db->head = p->next;
+
+ free (p->line);
+
+ if (NULL != p->eptr) {
+ db->ops->free (p->eptr);
+ }
+
+ free (p);
+ }
+ db->tail = NULL;
+}
+
+
+int commonio_setname (struct commonio_db *db, const char *name)
+{
+ snprintf (db->filename, sizeof (db->filename), "%s", name);
+ db->setname = true;
+ return 1;
+}
+
+
+bool commonio_present (const struct commonio_db *db)
+{
+ return (access (db->filename, F_OK) == 0);
+}
+
+
+int commonio_lock_nowait (struct commonio_db *db, bool log)
+{
+ char* file = NULL;
+ char* lock = NULL;
+ size_t lock_file_len;
+ size_t file_len;
+ int err = 0;
+
+ if (db->locked) {
+ return 1;
+ }
+ file_len = strlen(db->filename) + 11;/* %lu max size */
+ lock_file_len = strlen(db->filename) + 6; /* sizeof ".lock" */
+ file = (char*)malloc(file_len);
+ if (file == NULL) {
+ goto cleanup_ENOMEM;
+ }
+ lock = (char*)malloc(lock_file_len);
+ if (lock == NULL) {
+ goto cleanup_ENOMEM;
+ }
+ snprintf (file, file_len, "%s.%lu",
+ db->filename, (unsigned long) getpid ());
+ snprintf (lock, lock_file_len, "%s.lock", db->filename);
+ if (do_lock_file (file, lock, log) != 0) {
+ db->locked = true;
+ lock_count++;
+ err = 1;
+ }
+cleanup_ENOMEM:
+ free(file);
+ free(lock);
+ return err;
+}
+
+
+int commonio_lock (struct commonio_db *db)
+{
+ int i;
+
+#ifdef HAVE_LCKPWDF
+ /*
+ * Only if the system libc has a real lckpwdf() - the one from
+ * lockpw.c calls us and would cause infinite recursion!
+ * It is also not used with the prefix option.
+ */
+ if (!db->setname) {
+ /*
+ * Call lckpwdf() on the first lock.
+ * If it succeeds, call *_lock() only once
+ * (no retries, it should always succeed).
+ */
+ if (0 == lock_count) {
+ if (lckpwdf () == -1) {
+ if (geteuid () != 0) {
+ (void) fprintf (shadow_logfd,
+ "%s: Permission denied.\n",
+ shadow_progname);
+ }
+ return 0; /* failure */
+ }
+ }
+
+ if (commonio_lock_nowait (db, true) != 0) {
+ return 1; /* success */
+ }
+
+ ulckpwdf ();
+ return 0; /* failure */
+ }
+#endif /* !HAVE_LCKPWDF */
+
+ /*
+ * lckpwdf() not used - do it the old way.
+ */
+#ifndef LOCK_TRIES
+#define LOCK_TRIES 15
+#endif
+
+#ifndef LOCK_SLEEP
+#define LOCK_SLEEP 1
+#endif
+ for (i = 0; i < LOCK_TRIES; i++) {
+ if (i > 0) {
+ sleep (LOCK_SLEEP); /* delay between retries */
+ }
+ if (commonio_lock_nowait (db, i==LOCK_TRIES-1) != 0) {
+ return 1; /* success */
+ }
+ /* no unnecessary retries on "permission denied" errors */
+ if (geteuid () != 0) {
+ (void) fprintf (shadow_logfd, "%s: Permission denied.\n",
+ shadow_progname);
+ return 0;
+ }
+ }
+ return 0; /* failure */
+}
+
+static void dec_lock_count (void)
+{
+ if (lock_count > 0) {
+ lock_count--;
+ if (lock_count == 0) {
+ /* Tell nscd when lock count goes to zero,
+ if any of the files were changed. */
+ if (nscd_need_reload) {
+ nscd_flush_cache ("passwd");
+ nscd_flush_cache ("group");
+ sssd_flush_cache (SSSD_DB_PASSWD | SSSD_DB_GROUP);
+ nscd_need_reload = false;
+ }
+#ifdef HAVE_LCKPWDF
+ ulckpwdf ();
+#endif /* HAVE_LCKPWDF */
+ }
+ }
+}
+
+
+int commonio_unlock (struct commonio_db *db)
+{
+ char lock[1024];
+
+ if (db->isopen) {
+ db->readonly = true;
+ if (commonio_close (db) == 0) {
+ if (db->locked) {
+ dec_lock_count ();
+ }
+ return 0;
+ }
+ }
+ if (db->locked) {
+ /*
+ * Unlock in reverse order: remove the lock file,
+ * then call ulckpwdf() (if used) on last unlock.
+ */
+ db->locked = false;
+ snprintf (lock, sizeof lock, "%s.lock", db->filename);
+ unlink (lock);
+ dec_lock_count ();
+ return 1;
+ }
+ return 0;
+}
+
+
+/*
+ * Add an entry at the end.
+ *
+ * defines p->next, p->prev
+ * (unfortunately, owned special are not supported)
+ */
+static void add_one_entry (struct commonio_db *db,
+ /*@owned@*/struct commonio_entry *p)
+{
+ /*@-mustfreeonly@*/
+ p->next = NULL;
+ p->prev = db->tail;
+ /*@=mustfreeonly@*/
+ if (NULL == db->head) {
+ db->head = p;
+ }
+ if (NULL != db->tail) {
+ db->tail->next = p;
+ }
+ db->tail = p;
+}
+
+
+static bool name_is_nis (const char *name)
+{
+ return (('+' == name[0]) || ('-' == name[0]));
+}
+
+
+/*
+ * New entries are inserted before the first NIS entry. Order is preserved
+ * when db is written out.
+ */
+#ifndef KEEP_NIS_AT_END
+#define KEEP_NIS_AT_END 1
+#endif
+
+#if KEEP_NIS_AT_END
+static void add_one_entry_nis (struct commonio_db *db,
+ /*@owned@*/struct commonio_entry *newp);
+
+/*
+ * Insert an entry between the regular entries, and the NIS entries.
+ *
+ * defines newp->next, newp->prev
+ * (unfortunately, owned special are not supported)
+ */
+static void add_one_entry_nis (struct commonio_db *db,
+ /*@owned@*/struct commonio_entry *newp)
+{
+ struct commonio_entry *p;
+
+ for (p = db->head; NULL != p; p = p->next) {
+ if (name_is_nis (p->eptr ? db->ops->getname (p->eptr)
+ : p->line)) {
+ /*@-mustfreeonly@*/
+ newp->next = p;
+ newp->prev = p->prev;
+ /*@=mustfreeonly@*/
+ if (NULL != p->prev) {
+ p->prev->next = newp;
+ } else {
+ db->head = newp;
+ }
+ p->prev = newp;
+ return;
+ }
+ }
+ add_one_entry (db, newp);
+}
+#endif /* KEEP_NIS_AT_END */
+
+/* Initial buffer size, as well as increment if not sufficient
+ (for reading very long lines in group files). */
+#define BUFLEN 4096
+
+int commonio_open (struct commonio_db *db, int mode)
+{
+ char *buf;
+ char *cp;
+ char *line;
+ struct commonio_entry *p;
+ void *eptr = NULL;
+ int flags = mode;
+ size_t buflen;
+ int fd;
+ int saved_errno;
+
+ mode &= ~O_CREAT;
+
+ if ( db->isopen
+ || ( (O_RDONLY != mode)
+ && (O_RDWR != mode))) {
+ errno = EINVAL;
+ return 0;
+ }
+ db->readonly = (mode == O_RDONLY);
+ if (!db->readonly && !db->locked) {
+ errno = EACCES;
+ return 0;
+ }
+
+ db->head = NULL;
+ db->tail = NULL;
+ db->cursor = NULL;
+ db->changed = false;
+
+ fd = open (db->filename,
+ (db->readonly ? O_RDONLY : O_RDWR)
+ | O_NOCTTY | O_NONBLOCK | O_NOFOLLOW);
+ saved_errno = errno;
+ db->fp = NULL;
+ if (fd >= 0) {
+#ifdef WITH_TCB
+ if (tcb_is_suspect (fd) != 0) {
+ (void) close (fd);
+ errno = EINVAL;
+ return 0;
+ }
+#endif /* WITH_TCB */
+ db->fp = fdopen (fd, db->readonly ? "r" : "r+");
+ saved_errno = errno;
+ if (NULL == db->fp) {
+ (void) close (fd);
+ }
+ }
+ errno = saved_errno;
+
+ /*
+ * If O_CREAT was specified and the file didn't exist, it will be
+ * created by commonio_close(). We have no entries to read yet. --marekm
+ */
+ if (NULL == db->fp) {
+ if (((flags & O_CREAT) != 0) && (ENOENT == errno)) {
+ db->isopen = true;
+ return 1;
+ }
+ return 0;
+ }
+
+ /* Do not inherit fd in spawned processes (e.g. nscd) */
+ fcntl (fileno (db->fp), F_SETFD, FD_CLOEXEC);
+
+ buflen = BUFLEN;
+ buf = (char *) malloc (buflen);
+ if (NULL == buf) {
+ goto cleanup_ENOMEM;
+ }
+
+ while (db->ops->fgets (buf, (int) buflen, db->fp) == buf) {
+ while ( ((cp = strrchr (buf, '\n')) == NULL)
+ && (feof (db->fp) == 0)) {
+ size_t len;
+
+ buflen += BUFLEN;
+ cp = (char *) realloc (buf, buflen);
+ if (NULL == cp) {
+ goto cleanup_buf;
+ }
+ buf = cp;
+ len = strlen (buf);
+ if (db->ops->fgets (buf + len,
+ (int) (buflen - len),
+ db->fp) == NULL) {
+ goto cleanup_buf;
+ }
+ }
+ cp = strrchr (buf, '\n');
+ if (NULL != cp) {
+ *cp = '\0';
+ }
+
+ line = strdup (buf);
+ if (NULL == line) {
+ goto cleanup_buf;
+ }
+
+ if (name_is_nis (line)) {
+ eptr = NULL;
+ } else {
+ eptr = db->ops->parse (line);
+ if (NULL != eptr) {
+ eptr = db->ops->dup (eptr);
+ if (NULL == eptr) {
+ goto cleanup_line;
+ }
+ }
+ }
+
+ p = (struct commonio_entry *) malloc (sizeof *p);
+ if (NULL == p) {
+ goto cleanup_entry;
+ }
+
+ p->eptr = eptr;
+ p->line = line;
+ p->changed = false;
+
+ add_one_entry (db, p);
+ }
+
+ free (buf);
+
+ if (ferror (db->fp) != 0) {
+ goto cleanup_errno;
+ }
+
+ if ((NULL != db->ops->open_hook) && (db->ops->open_hook () == 0)) {
+ goto cleanup_errno;
+ }
+
+ db->isopen = true;
+ return 1;
+
+ cleanup_entry:
+ if (NULL != eptr) {
+ db->ops->free (eptr);
+ }
+ cleanup_line:
+ free (line);
+ cleanup_buf:
+ free (buf);
+ cleanup_ENOMEM:
+ errno = ENOMEM;
+ cleanup_errno:
+ saved_errno = errno;
+ free_linked_list (db);
+ fclose (db->fp);
+ db->fp = NULL;
+ errno = saved_errno;
+ return 0;
+}
+
+/*
+ * Sort given db according to cmp function (usually compares uids)
+ */
+int
+commonio_sort (struct commonio_db *db, int (*cmp) (const void *, const void *))
+{
+ struct commonio_entry **entries, *ptr;
+ size_t n = 0, i;
+#if KEEP_NIS_AT_END
+ struct commonio_entry *nis = NULL;
+#endif
+
+ for (ptr = db->head;
+ (NULL != ptr)
+#if KEEP_NIS_AT_END
+ && ((NULL == ptr->line)
+ || (('+' != ptr->line[0])
+ && ('-' != ptr->line[0])))
+#endif
+ ;
+ ptr = ptr->next) {
+ n++;
+ }
+#if KEEP_NIS_AT_END
+ if (NULL != ptr) {
+ nis = ptr;
+ }
+#endif
+
+ if (n <= 1) {
+ return 0;
+ }
+
+ entries = malloc (n * sizeof (struct commonio_entry *));
+ if (entries == NULL) {
+ return -1;
+ }
+
+ n = 0;
+ for (ptr = db->head;
+#if KEEP_NIS_AT_END
+ nis != ptr;
+#else
+ NULL != ptr;
+#endif
+/*@ -nullderef @*/
+ ptr = ptr->next
+/*@ +nullderef @*/
+ ) {
+ entries[n] = ptr;
+ n++;
+ }
+ qsort (entries, n, sizeof (struct commonio_entry *), cmp);
+
+ /* Take care of the head and tail separately */
+ db->head = entries[0];
+ n--;
+#if KEEP_NIS_AT_END
+ if (NULL == nis)
+#endif
+ {
+ db->tail = entries[n];
+ }
+ db->head->prev = NULL;
+ db->head->next = entries[1];
+ entries[n]->prev = entries[n - 1];
+#if KEEP_NIS_AT_END
+ entries[n]->next = nis;
+#else
+ entries[n]->next = NULL;
+#endif
+
+ /* Now other elements have prev and next entries */
+ for (i = 1; i < n; i++) {
+ entries[i]->prev = entries[i - 1];
+ entries[i]->next = entries[i + 1];
+ }
+
+ free (entries);
+ db->changed = true;
+
+ return 0;
+}
+
+/*
+ * Sort entries in db according to order in another.
+ */
+int commonio_sort_wrt (struct commonio_db *shadow,
+ const struct commonio_db *passwd)
+{
+ struct commonio_entry *head = NULL, *pw_ptr, *spw_ptr;
+ const char *name;
+
+ if ((NULL == shadow) || (NULL == shadow->head)) {
+ return 0;
+ }
+
+ for (pw_ptr = passwd->head; NULL != pw_ptr; pw_ptr = pw_ptr->next) {
+ if (NULL == pw_ptr->eptr) {
+ continue;
+ }
+ name = passwd->ops->getname (pw_ptr->eptr);
+ for (spw_ptr = shadow->head;
+ NULL != spw_ptr;
+ spw_ptr = spw_ptr->next) {
+ if (NULL == spw_ptr->eptr) {
+ continue;
+ }
+ if (strcmp (name, shadow->ops->getname (spw_ptr->eptr))
+ == 0) {
+ break;
+ }
+ }
+ if (NULL == spw_ptr) {
+ continue;
+ }
+ commonio_del_entry (shadow, spw_ptr);
+ spw_ptr->next = head;
+ head = spw_ptr;
+ }
+
+ for (spw_ptr = head; NULL != spw_ptr; spw_ptr = head) {
+ head = head->next;
+
+ if (NULL != shadow->head) {
+ shadow->head->prev = spw_ptr;
+ }
+ spw_ptr->next = shadow->head;
+ shadow->head = spw_ptr;
+ }
+
+ shadow->head->prev = NULL;
+ shadow->changed = true;
+
+ return 0;
+}
+
+/*
+ * write_all - Write the database to its file.
+ *
+ * It returns 0 if all the entries could be written correctly.
+ */
+static int write_all (const struct commonio_db *db)
+ /*@requires notnull db->fp@*/
+{
+ const struct commonio_entry *p;
+ void *eptr;
+
+ for (p = db->head; NULL != p; p = p->next) {
+ if (p->changed) {
+ eptr = p->eptr;
+ assert (NULL != eptr);
+ if (db->ops->put (eptr, db->fp) != 0) {
+ return -1;
+ }
+ } else if (NULL != p->line) {
+ if (db->ops->fputs (p->line, db->fp) == EOF) {
+ return -1;
+ }
+ if (putc ('\n', db->fp) == EOF) {
+ return -1;
+ }
+ }
+ }
+ return 0;
+}
+
+
+int commonio_close (struct commonio_db *db)
+{
+ char buf[1024];
+ int errors = 0;
+ struct stat sb;
+
+ if (!db->isopen) {
+ errno = EINVAL;
+ return 0;
+ }
+ db->isopen = false;
+
+ if (!db->changed || db->readonly) {
+ if (NULL != db->fp) {
+ (void) fclose (db->fp);
+ db->fp = NULL;
+ }
+ goto success;
+ }
+
+ if ((NULL != db->ops->close_hook) && (db->ops->close_hook () == 0)) {
+ goto fail;
+ }
+
+ memzero (&sb, sizeof sb);
+ if (NULL != db->fp) {
+ if (fstat (fileno (db->fp), &sb) != 0) {
+ (void) fclose (db->fp);
+ db->fp = NULL;
+ goto fail;
+ }
+
+ /*
+ * Create backup file.
+ */
+ snprintf (buf, sizeof buf, "%s-", db->filename);
+
+#ifdef WITH_SELINUX
+ if (set_selinux_file_context (db->filename, S_IFREG) != 0) {
+ errors++;
+ }
+#endif
+ if (create_backup (buf, db->fp) != 0) {
+ errors++;
+ }
+
+ if (fclose (db->fp) != 0) {
+ errors++;
+ }
+
+#ifdef WITH_SELINUX
+ if (reset_selinux_file_context () != 0) {
+ errors++;
+ }
+#endif
+ if (errors != 0) {
+ db->fp = NULL;
+ goto fail;
+ }
+ } else {
+ /*
+ * Default permissions for new [g]shadow files.
+ */
+ sb.st_mode = db->st_mode;
+ sb.st_uid = db->st_uid;
+ sb.st_gid = db->st_gid;
+ }
+
+ snprintf (buf, sizeof buf, "%s+", db->filename);
+
+#ifdef WITH_SELINUX
+ if (set_selinux_file_context (db->filename, S_IFREG) != 0) {
+ errors++;
+ }
+#endif
+
+ db->fp = fopen_set_perms (buf, "w", &sb);
+ if (NULL == db->fp) {
+ goto fail;
+ }
+
+ if (write_all (db) != 0) {
+ errors++;
+ }
+
+ if (fflush (db->fp) != 0) {
+ errors++;
+ }
+#ifdef HAVE_FSYNC
+ if (fsync (fileno (db->fp)) != 0) {
+ errors++;
+ }
+#else /* !HAVE_FSYNC */
+ sync ();
+#endif /* !HAVE_FSYNC */
+ if (fclose (db->fp) != 0) {
+ errors++;
+ }
+
+ db->fp = NULL;
+
+ if (errors != 0) {
+ unlink (buf);
+ goto fail;
+ }
+
+ if (lrename (buf, db->filename) != 0) {
+ goto fail;
+ }
+
+#ifdef WITH_SELINUX
+ if (reset_selinux_file_context () != 0) {
+ goto fail;
+ }
+#endif
+
+ nscd_need_reload = true;
+ goto success;
+ fail:
+ errors++;
+ success:
+
+ free_linked_list (db);
+ return errors == 0;
+}
+
+static /*@dependent@*/ /*@null@*/struct commonio_entry *next_entry_by_name (
+ struct commonio_db *db,
+ /*@null@*/struct commonio_entry *pos,
+ const char *name)
+{
+ struct commonio_entry *p;
+ void *ep;
+
+ if (NULL == pos) {
+ return NULL;
+ }
+
+ for (p = pos; NULL != p; p = p->next) {
+ ep = p->eptr;
+ if ( (NULL != ep)
+ && (strcmp (db->ops->getname (ep), name) == 0)) {
+ break;
+ }
+ }
+ return p;
+}
+
+static /*@dependent@*/ /*@null@*/struct commonio_entry *find_entry_by_name (
+ struct commonio_db *db,
+ const char *name)
+{
+ return next_entry_by_name (db, db->head, name);
+}
+
+
+int commonio_update (struct commonio_db *db, const void *eptr)
+{
+ struct commonio_entry *p;
+ void *nentry;
+
+ if (!db->isopen || db->readonly) {
+ errno = EINVAL;
+ return 0;
+ }
+ nentry = db->ops->dup (eptr);
+ if (NULL == nentry) {
+ errno = ENOMEM;
+ return 0;
+ }
+ p = find_entry_by_name (db, db->ops->getname (eptr));
+ if (NULL != p) {
+ if (next_entry_by_name (db, p->next, db->ops->getname (eptr)) != NULL) {
+ fprintf (shadow_logfd, _("Multiple entries named '%s' in %s. Please fix this with pwck or grpck.\n"), db->ops->getname (eptr), db->filename);
+ db->ops->free (nentry);
+ return 0;
+ }
+ db->ops->free (p->eptr);
+ p->eptr = nentry;
+ p->changed = true;
+ db->cursor = p;
+
+ db->changed = true;
+ return 1;
+ }
+ /* not found, new entry */
+ p = (struct commonio_entry *) malloc (sizeof *p);
+ if (NULL == p) {
+ db->ops->free (nentry);
+ errno = ENOMEM;
+ return 0;
+ }
+
+ p->eptr = nentry;
+ p->line = NULL;
+ p->changed = true;
+
+#if KEEP_NIS_AT_END
+ add_one_entry_nis (db, p);
+#else /* !KEEP_NIS_AT_END */
+ add_one_entry (db, p);
+#endif /* !KEEP_NIS_AT_END */
+
+ db->changed = true;
+ return 1;
+}
+
+#ifdef ENABLE_SUBIDS
+int commonio_append (struct commonio_db *db, const void *eptr)
+{
+ struct commonio_entry *p;
+ void *nentry;
+
+ if (!db->isopen || db->readonly) {
+ errno = EINVAL;
+ return 0;
+ }
+ nentry = db->ops->dup (eptr);
+ if (NULL == nentry) {
+ errno = ENOMEM;
+ return 0;
+ }
+ /* new entry */
+ p = (struct commonio_entry *) malloc (sizeof *p);
+ if (NULL == p) {
+ db->ops->free (nentry);
+ errno = ENOMEM;
+ return 0;
+ }
+
+ p->eptr = nentry;
+ p->line = NULL;
+ p->changed = true;
+ add_one_entry (db, p);
+
+ db->changed = true;
+ return 1;
+}
+#endif /* ENABLE_SUBIDS */
+
+void commonio_del_entry (struct commonio_db *db, const struct commonio_entry *p)
+{
+ if (p == db->cursor) {
+ db->cursor = p->next;
+ }
+
+ if (NULL != p->prev) {
+ p->prev->next = p->next;
+ } else {
+ db->head = p->next;
+ }
+
+ if (NULL != p->next) {
+ p->next->prev = p->prev;
+ } else {
+ db->tail = p->prev;
+ }
+
+ db->changed = true;
+}
+
+/*
+ * commonio_remove - Remove the entry of the given name from the database.
+ */
+int commonio_remove (struct commonio_db *db, const char *name)
+{
+ struct commonio_entry *p;
+
+ if (!db->isopen || db->readonly) {
+ errno = EINVAL;
+ return 0;
+ }
+ p = find_entry_by_name (db, name);
+ if (NULL == p) {
+ errno = ENOENT;
+ return 0;
+ }
+ if (next_entry_by_name (db, p->next, name) != NULL) {
+ fprintf (shadow_logfd, _("Multiple entries named '%s' in %s. Please fix this with pwck or grpck.\n"), name, db->filename);
+ return 0;
+ }
+
+ commonio_del_entry (db, p);
+
+ free (p->line);
+
+ if (NULL != p->eptr) {
+ db->ops->free (p->eptr);
+ }
+
+ return 1;
+}
+
+/*
+ * commonio_locate - Find the first entry with the specified name in
+ * the database.
+ *
+ * If found, it returns the entry and set the cursor of the database to
+ * that entry.
+ *
+ * Otherwise, it returns NULL.
+ */
+/*@observer@*/ /*@null@*/const void *commonio_locate (struct commonio_db *db, const char *name)
+{
+ struct commonio_entry *p;
+
+ if (!db->isopen) {
+ errno = EINVAL;
+ return NULL;
+ }
+ p = find_entry_by_name (db, name);
+ if (NULL == p) {
+ errno = ENOENT;
+ return NULL;
+ }
+ db->cursor = p;
+ return p->eptr;
+}
+
+/*
+ * commonio_rewind - Restore the database cursor to the first entry.
+ *
+ * It returns 0 on error, 1 on success.
+ */
+int commonio_rewind (struct commonio_db *db)
+{
+ if (!db->isopen) {
+ errno = EINVAL;
+ return 0;
+ }
+ db->cursor = NULL;
+ return 1;
+}
+
+/*
+ * commonio_next - Return the next entry of the specified database
+ *
+ * It returns the next entry, or NULL if no other entries could be found.
+ */
+/*@observer@*/ /*@null@*/const void *commonio_next (struct commonio_db *db)
+{
+ void *eptr;
+
+ if (!db->isopen) {
+ errno = EINVAL;
+ return 0;
+ }
+ if (NULL == db->cursor) {
+ db->cursor = db->head;
+ } else {
+ db->cursor = db->cursor->next;
+ }
+
+ while (NULL != db->cursor) {
+ eptr = db->cursor->eptr;
+ if (NULL != eptr) {
+ return eptr;
+ }
+
+ db->cursor = db->cursor->next;
+ }
+ return NULL;
+}
+
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-04 05:14:03 +0000