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-rw-r--r--uidlist.c621
1 files changed, 621 insertions, 0 deletions
diff --git a/uidlist.c b/uidlist.c
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index 0000000..99a3467
--- /dev/null
+++ b/uidlist.c
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+/*
+ * Handle the mapping of uid/gid and user/group names between systems.
+ *
+ * Copyright (C) 1996 Andrew Tridgell
+ * Copyright (C) 1996 Paul Mackerras
+ * Copyright (C) 2004-2022 Wayne Davison
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, visit the http://fsf.org website.
+ */
+
+/* If the source username/group does not exist on the target then use
+ * the numeric IDs. Never do any mapping for uid=0 or gid=0 as these
+ * are special. */
+
+#include "rsync.h"
+#include "ifuncs.h"
+#include "itypes.h"
+#include "io.h"
+
+extern int am_root;
+extern int preserve_uid;
+extern int preserve_gid;
+extern int preserve_acls;
+extern int numeric_ids;
+extern int xmit_id0_names;
+extern pid_t namecvt_pid;
+extern gid_t our_gid;
+extern char *usermap;
+extern char *groupmap;
+
+#ifdef HAVE_GETGROUPS
+# ifndef GETGROUPS_T
+# define GETGROUPS_T gid_t
+# endif
+#endif
+
+#define NFLAGS_WILD_NAME_MATCH (1<<0)
+#define NFLAGS_NAME_MATCH (1<<1)
+
+union name_or_id {
+ const char *name;
+ id_t max_id;
+};
+
+struct idlist {
+ struct idlist *next;
+ union name_or_id u;
+ id_t id, id2;
+ uint16 flags;
+};
+
+static struct idlist *uidlist, *uidmap;
+static struct idlist *gidlist, *gidmap;
+
+static inline int id_eq_uid(id_t id, uid_t uid)
+{
+ return id == (id_t)uid;
+}
+
+static inline int id_eq_gid(id_t id, gid_t gid)
+{
+ return id == (id_t)gid;
+}
+
+static id_t id_parse(const char *num_str)
+{
+ id_t tmp, num = 0;
+ const char *cp = num_str;
+
+ while (*cp) {
+ if (!isDigit(cp)) {
+ invalid_num:
+ rprintf(FERROR, "Invalid ID number: %s\n", num_str);
+ exit_cleanup(RERR_SYNTAX);
+ }
+ tmp = num * 10 + *cp++ - '0';
+ if (tmp < num)
+ goto invalid_num;
+ num = tmp;
+ }
+
+ return num;
+}
+
+static struct idlist *add_to_list(struct idlist **root, id_t id, union name_or_id noiu,
+ id_t id2, uint16 flags)
+{
+ struct idlist *node = new(struct idlist);
+ node->next = *root;
+ node->u = noiu;
+ node->id = id;
+ node->id2 = id2;
+ node->flags = flags;
+ *root = node;
+ return node;
+}
+
+/* turn a uid into a user name */
+const char *uid_to_user(uid_t uid)
+{
+ const char *name = NULL;
+
+ if (namecvt_pid) {
+ id_t id = uid;
+ namecvt_call("uid", &name, &id);
+ } else {
+ struct passwd *pass = getpwuid(uid);
+ if (pass)
+ name = strdup(pass->pw_name);
+ }
+
+ return name;
+}
+
+/* turn a gid into a group name */
+const char *gid_to_group(gid_t gid)
+{
+ const char *name = NULL;
+
+ if (namecvt_pid) {
+ id_t id = gid;
+ namecvt_call("gid", &name, &id);
+ } else {
+ struct group *grp = getgrgid(gid);
+ if (grp)
+ name = strdup(grp->gr_name);
+ }
+
+ return name;
+}
+
+/* Parse a user name or (optionally) a number into a uid */
+int user_to_uid(const char *name, uid_t *uid_p, BOOL num_ok)
+{
+ if (!name || !*name)
+ return 0;
+
+ if (num_ok && name[strspn(name, "0123456789")] == '\0') {
+ *uid_p = id_parse(name);
+ return 1;
+ }
+
+ if (namecvt_pid) {
+ id_t id;
+ if (!namecvt_call("usr", &name, &id))
+ return 0;
+ *uid_p = id;
+ } else {
+ struct passwd *pass = getpwnam(name);
+ if (!pass)
+ return 0;
+ *uid_p = pass->pw_uid;
+ }
+
+ return 1;
+}
+
+/* Parse a group name or (optionally) a number into a gid */
+int group_to_gid(const char *name, gid_t *gid_p, BOOL num_ok)
+{
+ if (!name || !*name)
+ return 0;
+
+ if (num_ok && name[strspn(name, "0123456789")] == '\0') {
+ *gid_p = id_parse(name);
+ return 1;
+ }
+
+ if (namecvt_pid) {
+ id_t id;
+ if (!namecvt_call("grp", &name, &id))
+ return 0;
+ *gid_p = id;
+ } else {
+ struct group *grp = getgrnam(name);
+ if (!grp)
+ return 0;
+ *gid_p = grp->gr_gid;
+ }
+
+ return 1;
+}
+
+static int is_in_group(gid_t gid)
+{
+#ifdef HAVE_GETGROUPS
+ static gid_t last_in;
+ static int ngroups = -2, last_out = -1;
+ static GETGROUPS_T *gidset;
+ int n;
+
+ if (gid == last_in && last_out >= 0)
+ return last_out;
+ if (ngroups < -1) {
+ if ((ngroups = getgroups(0, NULL)) < 0)
+ ngroups = 0;
+ gidset = new_array(GETGROUPS_T, ngroups+1);
+ if (ngroups > 0)
+ ngroups = getgroups(ngroups, gidset);
+ /* The default gid might not be in the list on some systems. */
+ for (n = 0; n < ngroups; n++) {
+ if ((gid_t)gidset[n] == our_gid)
+ break;
+ }
+ if (n == ngroups)
+ gidset[ngroups++] = our_gid;
+ if (DEBUG_GTE(OWN, 2)) {
+ int pos;
+ char *gidbuf = new_array(char, ngroups*21+32);
+ pos = snprintf(gidbuf, 32, "process has %d gid%s: ", ngroups, ngroups == 1? "" : "s");
+ for (n = 0; n < ngroups; n++) {
+ pos += snprintf(gidbuf+pos, 21, " %d", (int)gidset[n]);
+ }
+ rprintf(FINFO, "%s\n", gidbuf);
+ free(gidbuf);
+ }
+ }
+
+ last_in = gid;
+ for (n = 0; n < ngroups; n++) {
+ if ((gid_t)gidset[n] == gid)
+ return last_out = 1;
+ }
+ return last_out = 0;
+
+#else
+ return gid == our_gid;
+#endif
+}
+
+/* Add a uid/gid to its list of ids. Only called on receiving side. */
+static struct idlist *recv_add_id(struct idlist **idlist_ptr, struct idlist *idmap,
+ id_t id, const char *name)
+{
+ struct idlist *node;
+ union name_or_id noiu;
+ int flag;
+ id_t id2;
+
+ noiu.name = name; /* ensure that add_to_list() gets the raw value. */
+ if (!name)
+ name = "";
+
+ for (node = idmap; node; node = node->next) {
+ if (node->flags & NFLAGS_WILD_NAME_MATCH) {
+ if (!wildmatch(node->u.name, name))
+ continue;
+ } else if (node->flags & NFLAGS_NAME_MATCH) {
+ if (strcmp(node->u.name, name) != 0)
+ continue;
+ } else if (node->u.max_id) {
+ if (id < node->id || id > node->u.max_id)
+ continue;
+ } else {
+ if (node->id != id)
+ continue;
+ }
+ break;
+ }
+ if (node)
+ id2 = node->id2;
+ else if (*name && id) {
+ if (idlist_ptr == &uidlist) {
+ uid_t uid;
+ id2 = user_to_uid(name, &uid, False) ? (id_t)uid : id;
+ } else {
+ gid_t gid;
+ id2 = group_to_gid(name, &gid, False) ? (id_t)gid : id;
+ }
+ } else
+ id2 = id;
+
+ flag = idlist_ptr == &gidlist && !am_root && !is_in_group(id2) ? FLAG_SKIP_GROUP : 0;
+ node = add_to_list(idlist_ptr, id, noiu, id2, flag);
+
+ if (DEBUG_GTE(OWN, 2)) {
+ rprintf(FINFO, "%sid %u(%s) maps to %u\n",
+ idlist_ptr == &uidlist ? "u" : "g",
+ (unsigned)id, name, (unsigned)id2);
+ }
+
+ return node;
+}
+
+/* this function is a definite candidate for a faster algorithm */
+uid_t match_uid(uid_t uid)
+{
+ static struct idlist *last = NULL;
+ struct idlist *list;
+
+ if (last && id_eq_uid(last->id, uid))
+ return last->id2;
+
+ for (list = uidlist; list; list = list->next) {
+ if (id_eq_uid(list->id, uid))
+ break;
+ }
+
+ if (!list)
+ list = recv_add_id(&uidlist, uidmap, uid, NULL);
+ last = list;
+
+ return list->id2;
+}
+
+gid_t match_gid(gid_t gid, uint16 *flags_ptr)
+{
+ static struct idlist *last = NULL;
+ struct idlist *list;
+
+ if (last && id_eq_gid(last->id, gid))
+ list = last;
+ else {
+ for (list = gidlist; list; list = list->next) {
+ if (id_eq_gid(list->id, gid))
+ break;
+ }
+ if (!list)
+ list = recv_add_id(&gidlist, gidmap, gid, NULL);
+ last = list;
+ }
+
+ if (flags_ptr && list->flags & FLAG_SKIP_GROUP)
+ *flags_ptr |= FLAG_SKIP_GROUP;
+ return list->id2;
+}
+
+/* Add a uid to the list of uids. Only called on sending side. */
+const char *add_uid(uid_t uid)
+{
+ struct idlist *list;
+ struct idlist *node;
+ union name_or_id noiu;
+
+ for (list = uidlist; list; list = list->next) {
+ if (id_eq_uid(list->id, uid))
+ return NULL;
+ }
+
+ noiu.name = uid_to_user(uid);
+ node = add_to_list(&uidlist, uid, noiu, 0, 0);
+ return node->u.name;
+}
+
+/* Add a gid to the list of gids. Only called on sending side. */
+const char *add_gid(gid_t gid)
+{
+ struct idlist *list;
+ struct idlist *node;
+ union name_or_id noiu;
+
+ for (list = gidlist; list; list = list->next) {
+ if (id_eq_gid(list->id, gid))
+ return NULL;
+ }
+
+ noiu.name = gid_to_group(gid);
+ node = add_to_list(&gidlist, gid, noiu, 0, 0);
+ return node->u.name;
+}
+
+static void send_one_name(int f, id_t id, const char *name)
+{
+ int len;
+
+ if (!name)
+ name = "";
+ if ((len = strlen(name)) > 255) /* Impossible? */
+ len = 255;
+
+ write_varint30(f, id);
+ write_byte(f, len);
+ if (len)
+ write_buf(f, name, len);
+}
+
+static void send_one_list(int f, struct idlist *idlist, int usernames)
+{
+ struct idlist *list;
+
+ /* we send sequences of id/byte-len/name */
+ for (list = idlist; list; list = list->next) {
+ if (list->id && list->u.name)
+ send_one_name(f, list->id, list->u.name);
+ }
+
+ /* Terminate the uid list with 0 (which was excluded above).
+ * A modern rsync also sends the name of id 0. */
+ if (xmit_id0_names)
+ send_one_name(f, 0, usernames ? uid_to_user(0) : gid_to_group(0));
+ else
+ write_varint30(f, 0);
+}
+
+/* send a complete uid/gid mapping to the peer */
+void send_id_lists(int f)
+{
+ if (preserve_uid || preserve_acls)
+ send_one_list(f, uidlist, 1);
+
+ if (preserve_gid || preserve_acls)
+ send_one_list(f, gidlist, 0);
+}
+
+uid_t recv_user_name(int f, uid_t uid)
+{
+ struct idlist *node;
+ int len = read_byte(f);
+ char *name;
+
+ if (len) {
+ name = new_array(char, len+1);
+ read_sbuf(f, name, len);
+ if (numeric_ids < 0) {
+ free(name);
+ name = NULL;
+ }
+ } else
+ name = NULL;
+
+ node = recv_add_id(&uidlist, uidmap, uid, name); /* node keeps name's memory */
+ return node->id2;
+}
+
+gid_t recv_group_name(int f, gid_t gid, uint16 *flags_ptr)
+{
+ struct idlist *node;
+ int len = read_byte(f);
+ char *name;
+
+ if (len) {
+ name = new_array(char, len+1);
+ read_sbuf(f, name, len);
+ if (numeric_ids < 0) {
+ free(name);
+ name = NULL;
+ }
+ } else
+ name = NULL;
+
+ node = recv_add_id(&gidlist, gidmap, gid, name); /* node keeps name's memory */
+ if (flags_ptr && node->flags & FLAG_SKIP_GROUP)
+ *flags_ptr |= FLAG_SKIP_GROUP;
+ return node->id2;
+}
+
+/* recv a complete uid/gid mapping from the peer and map the uid/gid
+ * in the file list to local names */
+void recv_id_list(int f, struct file_list *flist)
+{
+ id_t id;
+ int i;
+
+ if ((preserve_uid || preserve_acls) && numeric_ids <= 0) {
+ /* read the uid list */
+ while ((id = read_varint30(f)) != 0)
+ recv_user_name(f, id);
+ if (xmit_id0_names)
+ recv_user_name(f, 0);
+ }
+
+ if ((preserve_gid || preserve_acls) && numeric_ids <= 0) {
+ /* read the gid list */
+ while ((id = read_varint30(f)) != 0)
+ recv_group_name(f, id, NULL);
+ if (xmit_id0_names)
+ recv_group_name(f, 0, NULL);
+ }
+
+ /* Now convert all the uids/gids from sender values to our values. */
+#ifdef SUPPORT_ACLS
+ if (preserve_acls && (!numeric_ids || usermap || groupmap))
+ match_acl_ids();
+#endif
+ if (am_root && preserve_uid && (!numeric_ids || usermap)) {
+ for (i = 0; i < flist->used; i++)
+ F_OWNER(flist->files[i]) = match_uid(F_OWNER(flist->files[i]));
+ }
+ if (preserve_gid && (!am_root || !numeric_ids || groupmap)) {
+ for (i = 0; i < flist->used; i++) {
+ F_GROUP(flist->files[i]) = match_gid(F_GROUP(flist->files[i]), &flist->files[i]->flags);
+ }
+ }
+}
+
+void parse_name_map(char *map, BOOL usernames)
+{
+ struct idlist **idmap_ptr = usernames ? &uidmap : &gidmap;
+ struct idlist **idlist_ptr = usernames ? &uidlist : &gidlist;
+ char *colon, *cp = map + strlen(map);
+ union name_or_id noiu;
+ id_t id1;
+ uint16 flags;
+
+ /* Parse the list in reverse, so the order in the struct is right. */
+ while (1) {
+ while (cp > map && cp[-1] != ',') cp--;
+ if (!(colon = strchr(cp, ':'))) {
+ rprintf(FERROR, "No colon found in --%smap: %s\n",
+ usernames ? "user" : "group", cp);
+ exit_cleanup(RERR_SYNTAX);
+ }
+ if (!colon[1]) {
+ rprintf(FERROR, "No name found after colon --%smap: %s\n",
+ usernames ? "user" : "group", cp);
+ exit_cleanup(RERR_SYNTAX);
+ }
+ *colon = '\0';
+
+ if (isDigit(cp)) {
+ char *dash = strchr(cp, '-');
+ if (strspn(cp, "0123456789-") != (size_t)(colon - cp)
+ || (dash && (!dash[1] || strchr(dash+1, '-')))) {
+ rprintf(FERROR, "Invalid number in --%smap: %s\n",
+ usernames ? "user" : "group", cp);
+ exit_cleanup(RERR_SYNTAX);
+ }
+ if (dash) {
+ *dash = '\0';
+ noiu.max_id = id_parse(dash+1);
+ } else
+ noiu.max_id = 0;
+ flags = 0;
+ id1 = id_parse(cp);
+ if (dash)
+ *dash = '-';
+ } else if (strpbrk(cp, "*[?")) {
+ flags = NFLAGS_WILD_NAME_MATCH;
+ noiu.name = cp;
+ id1 = 0;
+ } else {
+ flags = NFLAGS_NAME_MATCH;
+ noiu.name = cp;
+ id1 = 0;
+ }
+
+ if (usernames) {
+ uid_t uid;
+ if (user_to_uid(colon+1, &uid, True))
+ add_to_list(idmap_ptr, id1, noiu, uid, flags);
+ else {
+ rprintf(FERROR, "Unknown --usermap name on receiver: %s\n", colon+1);
+ }
+ } else {
+ gid_t gid;
+ if (group_to_gid(colon+1, &gid, True))
+ add_to_list(idmap_ptr, id1, noiu, gid, flags);
+ else {
+ rprintf(FERROR, "Unknown --groupmap name on receiver: %s\n", colon+1);
+ }
+ }
+
+ if (cp == map)
+ break;
+
+ *--cp = '\0'; /* replace comma */
+ }
+
+ /* If the sender isn't going to xmit the id0 name, we assume it's "root". */
+ if (!xmit_id0_names)
+ recv_add_id(idlist_ptr, *idmap_ptr, 0, numeric_ids ? NULL : "root");
+}
+
+#ifdef HAVE_GETGROUPLIST
+const char *getallgroups(uid_t uid, item_list *gid_list)
+{
+ struct passwd *pw;
+ gid_t *gid_array;
+ int size;
+
+ if ((pw = getpwuid(uid)) == NULL)
+ return "getpwuid failed";
+
+ gid_list->count = 0; /* We're overwriting any items in the list */
+ (void)EXPAND_ITEM_LIST(gid_list, gid_t, 32);
+ size = gid_list->malloced;
+
+ /* Get all the process's groups, with the pw_gid group first. */
+ if (getgrouplist(pw->pw_name, pw->pw_gid, gid_list->items, &size) < 0) {
+ if (size > (int)gid_list->malloced) {
+ gid_list->count = gid_list->malloced;
+ (void)EXPAND_ITEM_LIST(gid_list, gid_t, size);
+ if (getgrouplist(pw->pw_name, pw->pw_gid, gid_list->items, &size) < 0)
+ size = -1;
+ } else
+ size = -1;
+ if (size < 0)
+ return "getgrouplist failed";
+ }
+ gid_list->count = size;
+ gid_array = gid_list->items;
+
+ /* Paranoia: is the default group not first in the list? */
+ if (gid_array[0] != pw->pw_gid) {
+ int j;
+ for (j = 1; j < size; j++) {
+ if (gid_array[j] == pw->pw_gid)
+ break;
+ }
+ if (j == size) { /* The default group wasn't found! */
+ (void)EXPAND_ITEM_LIST(gid_list, gid_t, size+1);
+ gid_array = gid_list->items;
+ }
+ gid_array[j] = gid_array[0];
+ gid_array[0] = pw->pw_gid;
+ }
+
+ return NULL;
+}
+#endif
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