diff options
Diffstat (limited to 'lib/groupio.c')
-rw-r--r-- | lib/groupio.c | 438 |
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; +} + |