diff mbox series

[v2,12/13] tools/xenstore: use generic accounting for remaining quotas

Message ID 20230120100028.11142-13-jgross@suse.com (mailing list archive)
State Superseded
Headers show
Series tools/xenstore: rework internal accounting | expand

Commit Message

Jürgen Groß Jan. 20, 2023, 10 a.m. UTC
The maxrequests, node size, number of node permissions, and path length
quota are a little bit special, as they are either active in
transactions only (maxrequests), or they are just per item instead of
count values. Nevertheless being able to know the maximum number of
those quota related values per domain would be beneficial, so add them
to the generic accounting.

The per domain value will never show current numbers other than zero,
but the maximum number seen can be gathered the same way as the number
of nodes during a transaction.

To be able to use the const qualifier for a new function switch
domain_is_unprivileged() to take a const pointer, too.

Signed-off-by: Juergen Gross <jgross@suse.com>
---
 tools/xenstore/xenstored_core.c        | 14 ++++-----
 tools/xenstore/xenstored_core.h        |  2 +-
 tools/xenstore/xenstored_domain.c      | 39 ++++++++++++++++++++------
 tools/xenstore/xenstored_domain.h      |  6 ++++
 tools/xenstore/xenstored_transaction.c |  4 +--
 tools/xenstore/xenstored_watch.c       |  2 +-
 6 files changed, 48 insertions(+), 19 deletions(-)
diff mbox series

Patch

diff --git a/tools/xenstore/xenstored_core.c b/tools/xenstore/xenstored_core.c
index 5b85b69eb2..c34de5ca3a 100644
--- a/tools/xenstore/xenstored_core.c
+++ b/tools/xenstore/xenstored_core.c
@@ -799,8 +799,8 @@  int write_node_raw(struct connection *conn, TDB_DATA *key, struct node *node,
 		+ node->perms.num * sizeof(node->perms.p[0])
 		+ node->datalen + node->childlen;
 
-	if (!no_quota_check && domain_is_unprivileged(conn) &&
-	    data.dsize >= quota_max_entry_size) {
+	if (domain_max_chk(conn, ACC_NODESZ, data.dsize, quota_max_entry_size)
+	    && !no_quota_check) {
 		errno = ENOSPC;
 		return errno;
 	}
@@ -1168,7 +1168,7 @@  static bool valid_chars(const char *node)
 		       "0123456789-/_@") == strlen(node));
 }
 
-bool is_valid_nodename(const char *node)
+bool is_valid_nodename(const struct connection *conn, const char *node)
 {
 	int local_off = 0;
 	unsigned int domid;
@@ -1188,7 +1188,8 @@  bool is_valid_nodename(const char *node)
 	if (sscanf(node, "/local/domain/%5u/%n", &domid, &local_off) != 1)
 		local_off = 0;
 
-	if (strlen(node) > local_off + quota_max_path_len)
+	if (domain_max_chk(conn, ACC_PATHLEN, strlen(node) - local_off,
+			   quota_max_path_len))
 		return false;
 
 	return valid_chars(node);
@@ -1250,7 +1251,7 @@  static struct node *get_node_canonicalized(struct connection *conn,
 	*canonical_name = canonicalize(conn, ctx, name);
 	if (!*canonical_name)
 		return NULL;
-	if (!is_valid_nodename(*canonical_name)) {
+	if (!is_valid_nodename(conn, *canonical_name)) {
 		errno = EINVAL;
 		return NULL;
 	}
@@ -1775,8 +1776,7 @@  static int do_set_perms(const void *ctx, struct connection *conn,
 		return EINVAL;
 
 	perms.num--;
-	if (domain_is_unprivileged(conn) &&
-	    perms.num > quota_nb_perms_per_node)
+	if (domain_max_chk(conn, ACC_NPERM, perms.num, quota_nb_perms_per_node))
 		return ENOSPC;
 
 	permstr = in->buffer + strlen(in->buffer) + 1;
diff --git a/tools/xenstore/xenstored_core.h b/tools/xenstore/xenstored_core.h
index 6465105b4d..0140c25880 100644
--- a/tools/xenstore/xenstored_core.h
+++ b/tools/xenstore/xenstored_core.h
@@ -258,7 +258,7 @@  void check_store(void);
 void corrupt(struct connection *conn, const char *fmt, ...);
 
 /* Is this a valid node name? */
-bool is_valid_nodename(const char *node);
+bool is_valid_nodename(const struct connection *conn, const char *node);
 
 /* Get name of parent node. */
 char *get_parent(const void *ctx, const char *node);
diff --git a/tools/xenstore/xenstored_domain.c b/tools/xenstore/xenstored_domain.c
index 91695b6313..f431076505 100644
--- a/tools/xenstore/xenstored_domain.c
+++ b/tools/xenstore/xenstored_domain.c
@@ -431,7 +431,7 @@  int domain_get_quota(const void *ctx, struct connection *conn,
 		return ENOMEM;
 
 #define ent(t, e) \
-	resp = talloc_asprintf_append(resp, "%-16s: %8u (max: %8u\n", #t, \
+	resp = talloc_asprintf_append(resp, "%-17s: %8u (max: %8u\n", #t, \
 				      d->acc[e].val, d->acc[e].max); \
 	if (!resp) return ENOMEM
 
@@ -440,6 +440,7 @@  int domain_get_quota(const void *ctx, struct connection *conn,
 	ent(transactions, ACC_TRANS);
 	ent(outstanding, ACC_OUTST);
 	ent(memory, ACC_MEM);
+	ent(transaction-nodes, ACC_TRANSNODES);
 
 #undef ent
 
@@ -457,7 +458,7 @@  int domain_max_global_acc(const void *ctx, struct connection *conn)
 		return ENOMEM;
 
 #define ent(t, e) \
-	resp = talloc_asprintf_append(resp, "%-16s: %8u\n", #t,   \
+	resp = talloc_asprintf_append(resp, "%-17s: %8u\n", #t,   \
 				      acc_global_max[e]);         \
 	if (!resp) return ENOMEM
 
@@ -466,6 +467,7 @@  int domain_max_global_acc(const void *ctx, struct connection *conn)
 	ent(transactions, ACC_TRANS);
 	ent(outstanding, ACC_OUTST);
 	ent(memory, ACC_MEM);
+	ent(transaction-nodes, ACC_TRANSNODES);
 
 #undef ent
 
@@ -1080,13 +1082,23 @@  int domain_adjust_node_perms(struct node *node)
 	return 0;
 }
 
+static void domain_acc_chk_max(struct domain *d, enum accitem what,
+			       unsigned int val, unsigned int domid)
+{
+	assert(what < ARRAY_SIZE(d->acc));
+	assert(what < ARRAY_SIZE(acc_global_max));
+
+	if (val > d->acc[what].max)
+		d->acc[what].max = val;
+	if (val > acc_global_max[what] && domid_is_unprivileged(domid))
+		acc_global_max[what] = val;
+}
+
 static int domain_acc_add_chk(struct domain *d, enum accitem what, int add,
 			      unsigned int domid)
 {
 	unsigned int val;
 
-	assert(what < ARRAY_SIZE(d->acc));
-
 	if ((add < 0 && -add > d->acc[what].val) ||
 	    (d->acc[what].val + add) > INT_MAX) {
 		/*
@@ -1100,10 +1112,7 @@  static int domain_acc_add_chk(struct domain *d, enum accitem what, int add,
 	}
 
 	val = d->acc[what].val + add;
-	if (val > d->acc[what].max)
-		d->acc[what].max = val;
-	if (val > acc_global_max[what] && domid_is_unprivileged(domid))
-		acc_global_max[what] = val;
+	domain_acc_chk_max(d, what, val, domid);
 
 	return val;
 }
@@ -1219,6 +1228,20 @@  void domain_reset_global_acc(void)
 	hashtable_iterate(domhash, domain_reset_global_acc_sub, NULL);
 }
 
+bool domain_max_chk(const struct connection *conn, enum accitem what,
+		    unsigned int val, unsigned int quota)
+{
+	if (!conn || !conn->domain)
+		return false;
+
+	if (domain_is_unprivileged(conn) && val > quota)
+		return true;
+
+	domain_acc_chk_max(conn->domain, what, val, conn->id);
+
+	return false;
+}
+
 int domain_nbentry_inc(struct connection *conn, unsigned int domid)
 {
 	return (domain_acc_add(conn, domid, ACC_NODES, 1, false) < 0)
diff --git a/tools/xenstore/xenstored_domain.h b/tools/xenstore/xenstored_domain.h
index 162e7dc0d0..ff341dd8bf 100644
--- a/tools/xenstore/xenstored_domain.h
+++ b/tools/xenstore/xenstored_domain.h
@@ -27,6 +27,10 @@  enum accitem {
 	ACC_OUTST,
 	ACC_MEM,
 	ACC_TRANS,
+	ACC_TRANSNODES,
+	ACC_NPERM,
+	ACC_PATHLEN,
+	ACC_NODESZ,
 	ACC_N            /* Number of elements per domain. */
 };
 
@@ -118,6 +122,8 @@  void acc_drop(struct connection *conn);
 void acc_commit(struct connection *conn);
 int domain_max_global_acc(const void *ctx, struct connection *conn);
 void domain_reset_global_acc(void);
+bool domain_max_chk(const struct connection *conn, unsigned int what,
+		    unsigned int val, unsigned int quota);
 
 /* Write rate limiting */
 
diff --git a/tools/xenstore/xenstored_transaction.c b/tools/xenstore/xenstored_transaction.c
index ce6a12b576..7967770ca2 100644
--- a/tools/xenstore/xenstored_transaction.c
+++ b/tools/xenstore/xenstored_transaction.c
@@ -244,8 +244,8 @@  int access_node(struct connection *conn, struct node *node,
 
 	i = find_accessed_node(trans, node->name);
 	if (!i) {
-		if (trans->nodes >= quota_trans_nodes &&
-		    domain_is_unprivileged(conn)) {
+		if (domain_max_chk(conn, ACC_TRANSNODES, trans->nodes + 1,
+				   quota_trans_nodes)) {
 			ret = ENOSPC;
 			goto err;
 		}
diff --git a/tools/xenstore/xenstored_watch.c b/tools/xenstore/xenstored_watch.c
index e30cd89be3..61b1e3421e 100644
--- a/tools/xenstore/xenstored_watch.c
+++ b/tools/xenstore/xenstored_watch.c
@@ -176,7 +176,7 @@  static int check_watch_path(struct connection *conn, const void *ctx,
 		*path = canonicalize(conn, ctx, *path);
 		if (!*path)
 			return errno;
-		if (!is_valid_nodename(*path))
+		if (!is_valid_nodename(conn, *path))
 			goto inval;
 	}