[xen stable-4.12] tools/xenstore: ignore transaction id for [un]watch

[patchbot@xxxxxxx]

commit 444b7173db0a45df6c2e3dd3f6a58898e8638de3
Author:     Juergen Gross <jgross@xxxxxxxx>
AuthorDate: Thu Jun 11 16:12:38 2020 +0200
Commit:     Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Tue Dec 15 14:28:12 2020 +0100

    tools/xenstore: ignore transaction id for [un]watch
    
    Instead of ignoring the transaction id for XS_WATCH and XS_UNWATCH
    commands as it is documented in docs/misc/xenstore.txt, it is tested
    for validity today.
    
    Really ignore the transaction id for XS_WATCH and XS_UNWATCH.
    
    This is part of XSA-115.
    
    Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
    Reviewed-by: Julien Grall <jgrall@xxxxxxxxxx>
    Reviewed-by: Paul Durrant <paul@xxxxxxx>
---
 tools/xenstore/xenstored_core.c | 26 ++++++++++++++++----------
 1 file changed, 16 insertions(+), 10 deletions(-)

diff --git a/tools/xenstore/xenstored_core.c b/tools/xenstore/xenstored_core.c
index 43900a3914..ec06b4e032 100644
--- a/tools/xenstore/xenstored_core.c
+++ b/tools/xenstore/xenstored_core.c
@@ -1268,13 +1268,17 @@ static int do_set_perms(struct connection *conn, struct 
buffered_data *in)
 static struct {
        const char *str;
        int (*func)(struct connection *conn, struct buffered_data *in);
+       unsigned int flags;
+#define XS_FLAG_NOTID          (1U << 0)       /* Ignore transaction id. */
 } const wire_funcs[XS_TYPE_COUNT] = {
        [XS_CONTROL]           = { "CONTROL",           do_control },
        [XS_DIRECTORY]         = { "DIRECTORY",         send_directory },
        [XS_READ]              = { "READ",              do_read },
        [XS_GET_PERMS]         = { "GET_PERMS",         do_get_perms },
-       [XS_WATCH]             = { "WATCH",             do_watch },
-       [XS_UNWATCH]           = { "UNWATCH",           do_unwatch },
+       [XS_WATCH]             =
+           { "WATCH",         do_watch,        XS_FLAG_NOTID },
+       [XS_UNWATCH]           =
+           { "UNWATCH",       do_unwatch,      XS_FLAG_NOTID },
        [XS_TRANSACTION_START] = { "TRANSACTION_START", do_transaction_start },
        [XS_TRANSACTION_END]   = { "TRANSACTION_END",   do_transaction_end },
        [XS_INTRODUCE]         = { "INTRODUCE",         do_introduce },
@@ -1296,7 +1300,7 @@ static struct {
 
 static const char *sockmsg_string(enum xsd_sockmsg_type type)
 {
-       if ((unsigned)type < XS_TYPE_COUNT && wire_funcs[type].str)
+       if ((unsigned int)type < ARRAY_SIZE(wire_funcs) && wire_funcs[type].str)
                return wire_funcs[type].str;
 
        return "**UNKNOWN**";
@@ -1311,7 +1315,14 @@ static void process_message(struct connection *conn, 
struct buffered_data *in)
        enum xsd_sockmsg_type type = in->hdr.msg.type;
        int ret;
 
-       trans = transaction_lookup(conn, in->hdr.msg.tx_id);
+       if ((unsigned int)type >= XS_TYPE_COUNT || !wire_funcs[type].func) {
+               eprintf("Client unknown operation %i", type);
+               send_error(conn, ENOSYS);
+               return;
+       }
+
+       trans = (wire_funcs[type].flags & XS_FLAG_NOTID)
+               ? NULL : transaction_lookup(conn, in->hdr.msg.tx_id);
        if (IS_ERR(trans)) {
                send_error(conn, -PTR_ERR(trans));
                return;
@@ -1320,12 +1331,7 @@ static void process_message(struct connection *conn, 
struct buffered_data *in)
        assert(conn->transaction == NULL);
        conn->transaction = trans;
 
-       if ((unsigned)type < XS_TYPE_COUNT && wire_funcs[type].func)
-               ret = wire_funcs[type].func(conn, in);
-       else {
-               eprintf("Client unknown operation %i", type);
-               ret = ENOSYS;
-       }
+       ret = wire_funcs[type].func(conn, in);
        if (ret)
                send_error(conn, ret);
 
--
generated by git-patchbot for /home/xen/git/xen.git#stable-4.12