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Diffstat (limited to '')
| -rw-r--r-- | sftp-usergroup.c | 239 |
1 files changed, 239 insertions, 0 deletions
diff --git a/sftp-usergroup.c b/sftp-usergroup.c new file mode 100644 index 0000000..083930a --- /dev/null +++ b/sftp-usergroup.c @@ -0,0 +1,239 @@ +/* + * Copyright (c) 2022 Damien Miller <djm@mindrot.org> + * + * Permission to use, copy, modify, and distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + */ + +/* sftp client user/group lookup and caching */ + +#include "includes.h" + +#include <sys/types.h> +#include <openbsd-compat/sys-tree.h> + +#include <stdlib.h> +#include <stdarg.h> +#include <string.h> + +#include "log.h" +#include "xmalloc.h" + +#include "sftp-common.h" +#include "sftp-client.h" +#include "sftp-usergroup.h" + +/* Tree of id, name */ +struct idname { + u_int id; + char *name; + RB_ENTRY(idname) entry; + /* XXX implement bounded cache as TAILQ */ +}; +static int +idname_cmp(struct idname *a, struct idname *b) +{ + if (a->id == b->id) + return 0; + return a->id > b->id ? 1 : -1; +} +RB_HEAD(idname_tree, idname); +RB_GENERATE_STATIC(idname_tree, idname, entry, idname_cmp) + +static struct idname_tree user_idname = RB_INITIALIZER(&user_idname); +static struct idname_tree group_idname = RB_INITIALIZER(&group_idname); + +static void +idname_free(struct idname *idname) +{ + if (idname == NULL) + return; + free(idname->name); + free(idname); +} + +static void +idname_enter(struct idname_tree *tree, u_int id, const char *name) +{ + struct idname *idname; + + if ((idname = xcalloc(1, sizeof(*idname))) == NULL) + fatal_f("alloc"); + idname->id = id; + idname->name = xstrdup(name); + if (RB_INSERT(idname_tree, tree, idname) != NULL) + idname_free(idname); +} + +static const char * +idname_lookup(struct idname_tree *tree, u_int id) +{ + struct idname idname, *found; + + memset(&idname, 0, sizeof(idname)); + idname.id = id; + if ((found = RB_FIND(idname_tree, tree, &idname)) != NULL) + return found->name; + return NULL; +} + +static void +freenames(char **names, u_int nnames) +{ + u_int i; + + if (names == NULL) + return; + for (i = 0; i < nnames; i++) + free(names[i]); + free(names); +} + +static void +lookup_and_record(struct sftp_conn *conn, + u_int *uids, u_int nuids, u_int *gids, u_int ngids) +{ + int r; + u_int i; + char **usernames = NULL, **groupnames = NULL; + + if ((r = do_get_users_groups_by_id(conn, uids, nuids, gids, ngids, + &usernames, &groupnames)) != 0) { + debug_fr(r, "do_get_users_groups_by_id"); + return; + } + for (i = 0; i < nuids; i++) { + if (usernames[i] == NULL) { + debug3_f("uid %u not resolved", uids[i]); + continue; + } + debug3_f("record uid %u => \"%s\"", uids[i], usernames[i]); + idname_enter(&user_idname, uids[i], usernames[i]); + } + for (i = 0; i < ngids; i++) { + if (groupnames[i] == NULL) { + debug3_f("gid %u not resolved", gids[i]); + continue; + } + debug3_f("record gid %u => \"%s\"", gids[i], groupnames[i]); + idname_enter(&group_idname, gids[i], groupnames[i]); + } + freenames(usernames, nuids); + freenames(groupnames, ngids); +} + +static int +has_id(u_int id, u_int *ids, u_int nids) +{ + u_int i; + + if (nids == 0) + return 0; + + /* XXX O(N^2) */ + for (i = 0; i < nids; i++) { + if (ids[i] == id) + break; + } + return i < nids; +} + +static void +collect_ids_from_glob(glob_t *g, int user, u_int **idsp, u_int *nidsp) +{ + u_int id, i, n = 0, *ids = NULL; + + for (i = 0; g->gl_pathv[i] != NULL; i++) { + if (user) { + if (ruser_name(g->gl_statv[i]->st_uid) != NULL) + continue; /* Already seen */ + id = (u_int)g->gl_statv[i]->st_uid; + } else { + if (rgroup_name(g->gl_statv[i]->st_gid) != NULL) + continue; /* Already seen */ + id = (u_int)g->gl_statv[i]->st_gid; + } + if (has_id(id, ids, n)) + continue; + ids = xrecallocarray(ids, n, n + 1, sizeof(*ids)); + ids[n++] = id; + } + *idsp = ids; + *nidsp = n; +} + +void +get_remote_user_groups_from_glob(struct sftp_conn *conn, glob_t *g) +{ + u_int *uids = NULL, nuids = 0, *gids = NULL, ngids = 0; + + if (!can_get_users_groups_by_id(conn)) + return; + + collect_ids_from_glob(g, 1, &uids, &nuids); + collect_ids_from_glob(g, 0, &gids, &ngids); + lookup_and_record(conn, uids, nuids, gids, ngids); + free(uids); + free(gids); +} + +static void +collect_ids_from_dirents(SFTP_DIRENT **d, int user, u_int **idsp, u_int *nidsp) +{ + u_int id, i, n = 0, *ids = NULL; + + for (i = 0; d[i] != NULL; i++) { + if (user) { + if (ruser_name((uid_t)(d[i]->a.uid)) != NULL) + continue; /* Already seen */ + id = d[i]->a.uid; + } else { + if (rgroup_name((gid_t)(d[i]->a.gid)) != NULL) + continue; /* Already seen */ + id = d[i]->a.gid; + } + if (has_id(id, ids, n)) + continue; + ids = xrecallocarray(ids, n, n + 1, sizeof(*ids)); + ids[n++] = id; + } + *idsp = ids; + *nidsp = n; +} + +void +get_remote_user_groups_from_dirents(struct sftp_conn *conn, SFTP_DIRENT **d) +{ + u_int *uids = NULL, nuids = 0, *gids = NULL, ngids = 0; + + if (!can_get_users_groups_by_id(conn)) + return; + + collect_ids_from_dirents(d, 1, &uids, &nuids); + collect_ids_from_dirents(d, 0, &gids, &ngids); + lookup_and_record(conn, uids, nuids, gids, ngids); + free(uids); + free(gids); +} + +const char * +ruser_name(uid_t uid) +{ + return idname_lookup(&user_idname, (u_int)uid); +} + +const char * +rgroup_name(uid_t gid) +{ + return idname_lookup(&group_idname, (u_int)gid); +} + |