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-rw-r--r--lib/groupio.c438
1 files changed, 438 insertions, 0 deletions
diff --git a/lib/groupio.c b/lib/groupio.c
new file mode 100644
index 0000000..357a30e
--- /dev/null
+++ b/lib/groupio.c
@@ -0,0 +1,438 @@
+/*
+ * SPDX-FileCopyrightText: 1990 - 1994, Julianne Frances Haugh
+ * SPDX-FileCopyrightText: 1996 - 2000, Marek Michałkiewicz
+ * SPDX-FileCopyrightText: 2001 , Michał Moskal
+ * SPDX-FileCopyrightText: 2005 , Tomasz Kłoczko
+ * SPDX-FileCopyrightText: 2007 - 2010, Nicolas François
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <config.h>
+
+#ident "$Id$"
+
+#include <assert.h>
+#include <stdio.h>
+
+#include "prototypes.h"
+#include "defines.h"
+#include "commonio.h"
+#include "getdef.h"
+#include "groupio.h"
+
+static /*@null@*/struct commonio_entry *merge_group_entries (
+ /*@null@*/ /*@returned@*/struct commonio_entry *gr1,
+ /*@null@*/struct commonio_entry *gr2);
+static int split_groups (unsigned int max_members);
+static int group_open_hook (void);
+
+static /*@null@*/ /*@only@*/void *group_dup (const void *ent)
+{
+ const struct group *gr = ent;
+
+ return __gr_dup (gr);
+}
+
+static void group_free (/*@out@*/ /*@only@*/void *ent)
+{
+ struct group *gr = ent;
+
+ gr_free (gr);
+}
+
+static const char *group_getname (const void *ent)
+{
+ const struct group *gr = ent;
+
+ return gr->gr_name;
+}
+
+static void *group_parse (const char *line)
+{
+ return (void *) sgetgrent (line);
+}
+
+static int group_put (const void *ent, FILE * file)
+{
+ const struct group *gr = ent;
+
+ if ( (NULL == gr)
+ || (valid_field (gr->gr_name, ":\n") == -1)
+ || (valid_field (gr->gr_passwd, ":\n") == -1)
+ || (gr->gr_gid == (gid_t)-1)) {
+ return -1;
+ }
+
+ /* FIXME: fail also if gr->gr_mem == NULL ?*/
+ if (NULL != gr->gr_mem) {
+ size_t i;
+ for (i = 0; NULL != gr->gr_mem[i]; i++) {
+ if (valid_field (gr->gr_mem[i], ",:\n") == -1) {
+ return -1;
+ }
+ }
+ }
+
+ return (putgrent (gr, file) == -1) ? -1 : 0;
+}
+
+static int group_close_hook (void)
+{
+ unsigned int max_members = getdef_unum("MAX_MEMBERS_PER_GROUP", 0);
+
+ if (0 == max_members) {
+ return 1;
+ }
+
+ return split_groups (max_members);
+}
+
+static struct commonio_ops group_ops = {
+ group_dup,
+ group_free,
+ group_getname,
+ group_parse,
+ group_put,
+ fgetsx,
+ fputsx,
+ group_open_hook,
+ group_close_hook
+};
+
+static /*@owned@*/struct commonio_db group_db = {
+ GROUP_FILE, /* filename */
+ &group_ops, /* ops */
+ NULL, /* fp */
+#ifdef WITH_SELINUX
+ NULL, /* scontext */
+#endif
+ 0644, /* st_mode */
+ 0, /* st_uid */
+ 0, /* st_gid */
+ NULL, /* head */
+ NULL, /* tail */
+ NULL, /* cursor */
+ false, /* changed */
+ false, /* isopen */
+ false, /* locked */
+ false, /* readonly */
+ false /* setname */
+};
+
+int gr_setdbname (const char *filename)
+{
+ return commonio_setname (&group_db, filename);
+}
+
+/*@observer@*/const char *gr_dbname (void)
+{
+ return group_db.filename;
+}
+
+int gr_lock (void)
+{
+ return commonio_lock (&group_db);
+}
+
+int gr_open (int mode)
+{
+ return commonio_open (&group_db, mode);
+}
+
+/*@observer@*/ /*@null@*/const struct group *gr_locate (const char *name)
+{
+ return commonio_locate (&group_db, name);
+}
+
+/*@observer@*/ /*@null@*/const struct group *gr_locate_gid (gid_t gid)
+{
+ const struct group *grp;
+
+ gr_rewind ();
+ while ( ((grp = gr_next ()) != NULL)
+ && (grp->gr_gid != gid)) {
+ }
+
+ return grp;
+}
+
+int gr_update (const struct group *gr)
+{
+ return commonio_update (&group_db, (const void *) gr);
+}
+
+int gr_remove (const char *name)
+{
+ return commonio_remove (&group_db, name);
+}
+
+int gr_rewind (void)
+{
+ return commonio_rewind (&group_db);
+}
+
+/*@observer@*/ /*@null@*/const struct group *gr_next (void)
+{
+ return commonio_next (&group_db);
+}
+
+int gr_close (void)
+{
+ return commonio_close (&group_db);
+}
+
+int gr_unlock (void)
+{
+ return commonio_unlock (&group_db);
+}
+
+void __gr_set_changed (void)
+{
+ group_db.changed = true;
+}
+
+/*@dependent@*/ /*@null@*/struct commonio_entry *__gr_get_head (void)
+{
+ return group_db.head;
+}
+
+/*@observer@*/const struct commonio_db *__gr_get_db (void)
+{
+ return &group_db;
+}
+
+void __gr_del_entry (const struct commonio_entry *ent)
+{
+ commonio_del_entry (&group_db, ent);
+}
+
+static int gr_cmp (const void *p1, const void *p2)
+{
+ gid_t u1, u2;
+
+ if ((*(struct commonio_entry **) p1)->eptr == NULL) {
+ return 1;
+ }
+ if ((*(struct commonio_entry **) p2)->eptr == NULL) {
+ return -1;
+ }
+
+ u1 = ((struct group *) (*(struct commonio_entry **) p1)->eptr)->gr_gid;
+ u2 = ((struct group *) (*(struct commonio_entry **) p2)->eptr)->gr_gid;
+
+ if (u1 < u2) {
+ return -1;
+ } else if (u1 > u2) {
+ return 1;
+ } else {
+ return 0;
+ }
+}
+
+/* Sort entries by GID */
+int gr_sort ()
+{
+ return commonio_sort (&group_db, gr_cmp);
+}
+
+static int group_open_hook (void)
+{
+ unsigned int max_members = getdef_unum("MAX_MEMBERS_PER_GROUP", 0);
+ struct commonio_entry *gr1, *gr2;
+
+ if (0 == max_members) {
+ return 1;
+ }
+
+ for (gr1 = group_db.head; NULL != gr1; gr1 = gr1->next) {
+ for (gr2 = gr1->next; NULL != gr2; gr2 = gr2->next) {
+ struct group *g1 = (struct group *)gr1->eptr;
+ struct group *g2 = (struct group *)gr2->eptr;
+ if (NULL != g1 &&
+ NULL != g2 &&
+ 0 == strcmp (g1->gr_name, g2->gr_name) &&
+ 0 == strcmp (g1->gr_passwd, g2->gr_passwd) &&
+ g1->gr_gid == g2->gr_gid) {
+ /* Both group entries refer to the same
+ * group. It is a split group. Merge the
+ * members. */
+ gr1 = merge_group_entries (gr1, gr2);
+ if (NULL == gr1)
+ return 0;
+ /* Unlink gr2 */
+ if (NULL != gr2->next) {
+ gr2->next->prev = gr2->prev;
+ }
+ /* gr2 does not start with head */
+ assert (NULL != gr2->prev);
+ gr2->prev->next = gr2->next;
+ }
+ }
+ assert (NULL != gr1);
+ }
+
+ return 1;
+}
+
+/*
+ * Merge the list of members of the two group entries.
+ *
+ * The commonio_entry arguments shall be group entries.
+ *
+ * You should not merge the members of two groups if they don't have the
+ * same name, password and gid.
+ *
+ * It merge the members of the second entry in the first one, and return
+ * the modified first entry on success, or NULL on failure (with errno
+ * set).
+ */
+static /*@null@*/struct commonio_entry *merge_group_entries (
+ /*@null@*/ /*@returned@*/struct commonio_entry *gr1,
+ /*@null@*/struct commonio_entry *gr2)
+{
+ struct group *gptr1;
+ struct group *gptr2;
+ char **new_members;
+ size_t members = 0;
+ char *new_line;
+ size_t new_line_len, i;
+ if (NULL == gr2 || NULL == gr1) {
+ errno = EINVAL;
+ return NULL;
+ }
+
+ gptr1 = (struct group *)gr1->eptr;
+ gptr2 = (struct group *)gr2->eptr;
+ if (NULL == gptr2 || NULL == gptr1) {
+ errno = EINVAL;
+ return NULL;
+ }
+
+ /* Concatenate the 2 lines */
+ new_line_len = strlen (gr1->line) + strlen (gr2->line) +1;
+ new_line = (char *)malloc (new_line_len + 1);
+ if (NULL == new_line) {
+ errno = ENOMEM;
+ return NULL;
+ }
+ snprintf(new_line, new_line_len + 1, "%s\n%s", gr1->line, gr2->line);
+
+ /* Concatenate the 2 list of members */
+ for (i=0; NULL != gptr1->gr_mem[i]; i++);
+ members += i;
+ for (i=0; NULL != gptr2->gr_mem[i]; i++) {
+ char **pmember = gptr1->gr_mem;
+ while (NULL != *pmember) {
+ if (0 == strcmp(*pmember, gptr2->gr_mem[i])) {
+ break;
+ }
+ pmember++;
+ }
+ if (NULL == *pmember) {
+ members++;
+ }
+ }
+ new_members = (char **)calloc ( (members+1), sizeof(char*) );
+ if (NULL == new_members) {
+ free (new_line);
+ errno = ENOMEM;
+ return NULL;
+ }
+ for (i=0; NULL != gptr1->gr_mem[i]; i++) {
+ new_members[i] = gptr1->gr_mem[i];
+ }
+ /* NULL termination enforced by above calloc */
+
+ members = i;
+ for (i=0; NULL != gptr2->gr_mem[i]; i++) {
+ char **pmember = new_members;
+ while (NULL != *pmember) {
+ if (0 == strcmp(*pmember, gptr2->gr_mem[i])) {
+ break;
+ }
+ pmember++;
+ }
+ if (NULL == *pmember) {
+ new_members[members] = gptr2->gr_mem[i];
+ members++;
+ new_members[members] = NULL;
+ }
+ }
+
+ gr1->line = new_line;
+ gptr1->gr_mem = new_members;
+
+ return gr1;
+}
+
+/*
+ * Scan the group database and split the groups which have more members
+ * than specified, if this is the result from a current change.
+ *
+ * Return 0 on failure (errno set) and 1 on success.
+ */
+static int split_groups (unsigned int max_members)
+{
+ struct commonio_entry *gr;
+
+ for (gr = group_db.head; NULL != gr; gr = gr->next) {
+ struct group *gptr = (struct group *)gr->eptr;
+ struct commonio_entry *new;
+ struct group *new_gptr;
+ unsigned int members = 0;
+ unsigned int i;
+
+ /* Check if this group must be split */
+ if (!gr->changed) {
+ continue;
+ }
+ if (NULL == gptr) {
+ continue;
+ }
+ for (members = 0; NULL != gptr->gr_mem[members]; members++);
+ if (members <= max_members) {
+ continue;
+ }
+
+ new = (struct commonio_entry *) malloc (sizeof *new);
+ if (NULL == new) {
+ errno = ENOMEM;
+ return 0;
+ }
+ new->eptr = group_dup(gr->eptr);
+ if (NULL == new->eptr) {
+ free (new);
+ errno = ENOMEM;
+ return 0;
+ }
+ new_gptr = (struct group *)new->eptr;
+ new->line = NULL;
+ new->changed = true;
+
+ /* Enforce the maximum number of members on gptr */
+ for (i = max_members; NULL != gptr->gr_mem[i]; i++) {
+ free (gptr->gr_mem[i]);
+ gptr->gr_mem[i] = NULL;
+ }
+ /* Shift all the members */
+ /* The number of members in new_gptr will be check later */
+ for (i = 0; NULL != new_gptr->gr_mem[i + max_members]; i++) {
+ free (new_gptr->gr_mem[i]);
+ new_gptr->gr_mem[i] = new_gptr->gr_mem[i + max_members];
+ new_gptr->gr_mem[i + max_members] = NULL;
+ }
+ for (; NULL != new_gptr->gr_mem[i]; i++) {
+ free (new_gptr->gr_mem[i]);
+ new_gptr->gr_mem[i] = NULL;
+ }
+
+ /* insert the new entry in the list */
+ new->prev = gr;
+ new->next = gr->next;
+ gr->next = new;
+ }
+
+ return 1;
+}
+
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