upstream: use users-groups-by-id@openssh.com sftp-server extension

(when available) to fill in user/group names for directory listings.
Implement a client-side cache of see uid/gid=>user/group names. ok markus@

OpenBSD-Commit-ID: f239aeeadfa925a37ceee36ee8b256b8ccf4466e

4 files changed, 278 insertions, 5 deletions

diff --git a/Makefile.in b/Makefile.in
index 778c66cf..5dde2baa 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -153,7 +153,7 @@ SSHKEYSCAN_OBJS=ssh-keyscan.o $(SKOBJS)
 
 SFTPSERVER_OBJS=sftp-common.o sftp-server.o sftp-server-main.o
 
-SFTP_OBJS=	sftp.o progressmeter.o $(SFTP_CLIENT_OBJS)
+SFTP_OBJS=	sftp.o sftp-usergroup.o progressmeter.o $(SFTP_CLIENT_OBJS)
 
 MANPAGES	= moduli.5.out scp.1.out ssh-add.1.out ssh-agent.1.out ssh-keygen.1.out ssh-keyscan.1.out ssh.1.out sshd.8.out sftp-server.8.out sftp.1.out ssh-keysign.8.out ssh-pkcs11-helper.8.out ssh-sk-helper.8.out sshd_config.5.out ssh_config.5.out
 MANPAGES_IN	= moduli.5 scp.1 ssh-add.1 ssh-agent.1 ssh-keygen.1 ssh-keyscan.1 ssh.1 sshd.8 sftp-server.8 sftp.1 ssh-keysign.8 ssh-pkcs11-helper.8 ssh-sk-helper.8 sshd_config.5 ssh_config.5
diff --git a/sftp-usergroup.c b/sftp-usergroup.c
new file mode 100644
index 00000000..fa06fd0a
--- /dev/null
+++ b/sftp-usergroup.c
@@ -0,0 +1,240 @@
+/*
+ * 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 <glob.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);
+}
+
diff --git a/sftp-usergroup.h b/sftp-usergroup.h
new file mode 100644
index 00000000..2711faf3
--- /dev/null
+++ b/sftp-usergroup.h
@@ -0,0 +1,25 @@
+/*
+ * 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 */
+
+/* Lookup uids/gids and populate cache */
+void get_remote_user_groups_from_glob(struct sftp_conn *conn, glob_t *g);
+void get_remote_user_groups_from_dirents(struct sftp_conn *conn, SFTP_DIRENT **d);
+
+/* Return user/group name from cache or NULL if not found */
+const char *ruser_name(uid_t uid);
+const char *rgroup_name(uid_t gid);
diff --git a/sftp.c b/sftp.c
index 2d1186ac..c3c347e0 100644
--- a/sftp.c
+++ b/sftp.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: sftp.c,v 1.221 2022/09/19 10:41:58 djm Exp $ */
+/* $OpenBSD: sftp.c,v 1.222 2022/09/19 10:46:00 djm Exp $ */
 /*
  * Copyright (c) 2001-2004 Damien Miller <djm@openbsd.org>
  *
@@ -68,6 +68,7 @@ typedef void EditLine;
 #include "sshbuf.h"
 #include "sftp-common.h"
 #include "sftp-client.h"
+#include "sftp-usergroup.h"
 
 /* File to read commands from */
 FILE* infile;
@@ -871,6 +872,7 @@ do_ls_dir(struct sftp_conn *conn, const char *path,
 		qsort(d, n, sizeof(*d), sdirent_comp);
 	}
 
+	get_remote_user_groups_from_dirents(conn, d);
 	for (n = 0; d[n] != NULL && !interrupted; n++) {
 		char *tmp, *fname;
 
@@ -882,14 +884,17 @@ do_ls_dir(struct sftp_conn *conn, const char *path,
 		free(tmp);
 
 		if (lflag & LS_LONG_VIEW) {
-			if (lflag & (LS_NUMERIC_VIEW|LS_SI_UNITS)) {
+			if ((lflag & (LS_NUMERIC_VIEW|LS_SI_UNITS)) != 0 ||
+			    can_get_users_groups_by_id(conn)) {
 				char *lname;
 				struct stat sb;
 
 				memset(&sb, 0, sizeof(sb));
 				attrib_to_stat(&d[n]->a, &sb);
 				lname = ls_file(fname, &sb, 1,
-				    (lflag & LS_SI_UNITS), NULL, NULL);
+				    (lflag & LS_SI_UNITS),
+				    ruser_name(sb.st_uid),
+				    rgroup_name(sb.st_gid));
 				mprintf("%s\n", lname);
 				free(lname);
 			} else
@@ -1017,6 +1022,7 @@ do_globbed_ls(struct sftp_conn *conn, const char *path,
 		sort_glob = NULL;
 	}
 
+	get_remote_user_groups_from_glob(conn, &g);
 	for (j = 0; j < nentries && !interrupted; j++) {
 		i = indices[j];
 		fname = path_strip(g.gl_pathv[i], strip_path);
@@ -1026,7 +1032,9 @@ do_globbed_ls(struct sftp_conn *conn, const char *path,
 				continue;
 			}
 			lname = ls_file(fname, g.gl_statv[i], 1,
-			    (lflag & LS_SI_UNITS), NULL, NULL);
+			    (lflag & LS_SI_UNITS),
+			    ruser_name(g.gl_statv[i]->st_uid),
+			    rgroup_name(g.gl_statv[i]->st_gid));
 			mprintf("%s\n", lname);
 			free(lname);
 		} else {