diff mbox series

[v2,1/2] tools/xenstore: move per connection read and write func hooks into a struct

Message ID 20210514115620.32731-2-jgross@suse.com (mailing list archive)
State Superseded
Headers show
Series tools/xenstore: simplify xenstored main loop | expand

Commit Message

Jürgen Groß May 14, 2021, 11:56 a.m. UTC 
Put the interface type specific functions into an own structure and let
struct connection contain only a pointer to that new function vector.

Don't even define the socket based functions in case of NO_SOCKETS
(Mini-OS).

Signed-off-by: Juergen Gross <jgross@suse.com>
---
V2:
- split off from V1 patch (Julien Grall)
- use const qualifier (Julien Grall)
- drop socket specific case for Mini-OS (Julien Grall)
---
 tools/xenstore/xenstored_core.c   | 44 +++++++++++++------------------
 tools/xenstore/xenstored_core.h   | 19 +++++++------
 tools/xenstore/xenstored_domain.c | 13 +++++++--
 3 files changed, 38 insertions(+), 38 deletions(-)

Comments

Julien Grall May 14, 2021, 4:33 p.m. UTC | #1 
Hi Juergen,

On 14/05/2021 12:56, Juergen Gross wrote:
> -struct connection *new_connection(connwritefn_t *write, connreadfn_t *read);
> +struct connection *new_connection(const struct interface_funcs *funcs);
>   struct connection *get_connection_by_id(unsigned int conn_id);
>   void check_store(void);
>   void corrupt(struct connection *conn, const char *fmt, ...);
> @@ -254,10 +256,7 @@ void finish_daemonize(void);
>   /* Open a pipe for signal handling */
>   void init_pipe(int reopen_log_pipe[2]);
>   
> -int writefd(struct connection *conn, const void *data, unsigned int len);
> -int readfd(struct connection *conn, void *data, unsigned int len);
> -
> -extern struct interface_funcs socket_funcs;
> +extern const struct interface_funcs socket_funcs;
Shouldn't this be protected with #ifdef NO_SOCKETS?

The rest looks good to me:

Reviewed-by: Julien Grall <jgrall@amazon.com>

Cheers,
Jürgen Groß May 17, 2021, 6:07 a.m. UTC | #2 
On 14.05.21 18:33, Julien Grall wrote:
> Hi Juergen,
> 
> On 14/05/2021 12:56, Juergen Gross wrote:
>> -struct connection *new_connection(connwritefn_t *write, connreadfn_t 
>> *read);
>> +struct connection *new_connection(const struct interface_funcs *funcs);
>>   struct connection *get_connection_by_id(unsigned int conn_id);
>>   void check_store(void);
>>   void corrupt(struct connection *conn, const char *fmt, ...);
>> @@ -254,10 +256,7 @@ void finish_daemonize(void);
>>   /* Open a pipe for signal handling */
>>   void init_pipe(int reopen_log_pipe[2]);
>> -int writefd(struct connection *conn, const void *data, unsigned int 
>> len);
>> -int readfd(struct connection *conn, void *data, unsigned int len);
>> -
>> -extern struct interface_funcs socket_funcs;
>> +extern const struct interface_funcs socket_funcs;
> Shouldn't this be protected with #ifdef NO_SOCKETS?

Yes, I can add it.

> 
> The rest looks good to me:
> 
> Reviewed-by: Julien Grall <jgrall@amazon.com>

Thanks,

Juergen
diff mbox series

Patch

diff --git a/tools/xenstore/xenstored_core.c b/tools/xenstore/xenstored_core.c
index 4b7b71cfb3..856f518075 100644
--- a/tools/xenstore/xenstored_core.c
+++ b/tools/xenstore/xenstored_core.c
@@ -226,8 +226,8 @@  static bool write_messages(struct connection *conn)
 				sockmsg_string(out->hdr.msg.type),
 				out->hdr.msg.len,
 				out->buffer, conn);
-		ret = conn->write(conn, out->hdr.raw + out->used,
-				  sizeof(out->hdr) - out->used);
+		ret = conn->funcs->write(conn, out->hdr.raw + out->used,
+					 sizeof(out->hdr) - out->used);
 		if (ret < 0)
 			return false;
 
@@ -243,8 +243,8 @@  static bool write_messages(struct connection *conn)
 			return true;
 	}
 
-	ret = conn->write(conn, out->buffer + out->used,
-			  out->hdr.msg.len - out->used);
+	ret = conn->funcs->write(conn, out->buffer + out->used,
+				 out->hdr.msg.len - out->used);
 	if (ret < 0)
 		return false;
 
@@ -1531,8 +1531,8 @@  static void handle_input(struct connection *conn)
 	/* Not finished header yet? */
 	if (in->inhdr) {
 		if (in->used != sizeof(in->hdr)) {
-			bytes = conn->read(conn, in->hdr.raw + in->used,
-					   sizeof(in->hdr) - in->used);
+			bytes = conn->funcs->read(conn, in->hdr.raw + in->used,
+						  sizeof(in->hdr) - in->used);
 			if (bytes < 0)
 				goto bad_client;
 			in->used += bytes;
@@ -1557,8 +1557,8 @@  static void handle_input(struct connection *conn)
 		in->inhdr = false;
 	}
 
-	bytes = conn->read(conn, in->buffer + in->used,
-			   in->hdr.msg.len - in->used);
+	bytes = conn->funcs->read(conn, in->buffer + in->used,
+				  in->hdr.msg.len - in->used);
 	if (bytes < 0)
 		goto bad_client;
 
@@ -1581,7 +1581,7 @@  static void handle_output(struct connection *conn)
 		ignore_connection(conn);
 }
 
-struct connection *new_connection(connwritefn_t *write, connreadfn_t *read)
+struct connection *new_connection(const struct interface_funcs *funcs)
 {
 	struct connection *new;
 
@@ -1591,8 +1591,7 @@  struct connection *new_connection(connwritefn_t *write, connreadfn_t *read)
 
 	new->fd = -1;
 	new->pollfd_idx = -1;
-	new->write = write;
-	new->read = read;
+	new->funcs = funcs;
 	new->is_ignored = false;
 	new->transaction_started = 0;
 	INIT_LIST_HEAD(&new->out_list);
@@ -1621,20 +1620,8 @@  struct connection *get_connection_by_id(unsigned int conn_id)
 static void accept_connection(int sock)
 {
 }
-
-int writefd(struct connection *conn, const void *data, unsigned int len)
-{
-	errno = EBADF;
-	return -1;
-}
-
-int readfd(struct connection *conn, void *data, unsigned int len)
-{
-	errno = EBADF;
-	return -1;
-}
 #else
-int writefd(struct connection *conn, const void *data, unsigned int len)
+static int writefd(struct connection *conn, const void *data, unsigned int len)
 {
 	int rc;
 
@@ -1650,7 +1637,7 @@  int writefd(struct connection *conn, const void *data, unsigned int len)
 	return rc;
 }
 
-int readfd(struct connection *conn, void *data, unsigned int len)
+static int readfd(struct connection *conn, void *data, unsigned int len)
 {
 	int rc;
 
@@ -1672,6 +1659,11 @@  int readfd(struct connection *conn, void *data, unsigned int len)
 	return rc;
 }
 
+const struct interface_funcs socket_funcs = {
+	.write = writefd,
+	.read = readfd,
+};
+
 static void accept_connection(int sock)
 {
 	int fd;
@@ -1681,7 +1673,7 @@  static void accept_connection(int sock)
 	if (fd < 0)
 		return;
 
-	conn = new_connection(writefd, readfd);
+	conn = new_connection(&socket_funcs);
 	if (conn)
 		conn->fd = fd;
 	else
diff --git a/tools/xenstore/xenstored_core.h b/tools/xenstore/xenstored_core.h
index 6a6d0448e8..021e41076d 100644
--- a/tools/xenstore/xenstored_core.h
+++ b/tools/xenstore/xenstored_core.h
@@ -86,8 +86,11 @@  struct delayed_request {
 };
 
 struct connection;
-typedef int connwritefn_t(struct connection *, const void *, unsigned int);
-typedef int connreadfn_t(struct connection *, void *, unsigned int);
+
+struct interface_funcs {
+	int (*write)(struct connection *, const void *, unsigned int);
+	int (*read)(struct connection *, void *, unsigned int);
+};
 
 struct connection
 {
@@ -131,9 +134,8 @@  struct connection
 	/* My watches. */
 	struct list_head watches;
 
-	/* Methods for communicating over this connection: write can be NULL */
-	connwritefn_t *write;
-	connreadfn_t *read;
+	/* Methods for communicating over this connection. */
+	const struct interface_funcs *funcs;
 
 	/* Support for live update: connection id. */
 	unsigned int conn_id;
@@ -196,7 +198,7 @@  int write_node_raw(struct connection *conn, TDB_DATA *key, struct node *node,
 struct node *read_node(struct connection *conn, const void *ctx,
 		       const char *name);
 
-struct connection *new_connection(connwritefn_t *write, connreadfn_t *read);
+struct connection *new_connection(const struct interface_funcs *funcs);
 struct connection *get_connection_by_id(unsigned int conn_id);
 void check_store(void);
 void corrupt(struct connection *conn, const char *fmt, ...);
@@ -254,10 +256,7 @@  void finish_daemonize(void);
 /* Open a pipe for signal handling */
 void init_pipe(int reopen_log_pipe[2]);
 
-int writefd(struct connection *conn, const void *data, unsigned int len);
-int readfd(struct connection *conn, void *data, unsigned int len);
-
-extern struct interface_funcs socket_funcs;
+extern const struct interface_funcs socket_funcs;
 extern xengnttab_handle **xgt_handle;
 
 int remember_string(struct hashtable *hash, const char *str);
diff --git a/tools/xenstore/xenstored_domain.c b/tools/xenstore/xenstored_domain.c
index 0c17937c0f..f3cd56050e 100644
--- a/tools/xenstore/xenstored_domain.c
+++ b/tools/xenstore/xenstored_domain.c
@@ -172,6 +172,11 @@  static int readchn(struct connection *conn, void *data, unsigned int len)
 	return len;
 }
 
+static const struct interface_funcs domain_funcs = {
+	.write = writechn,
+	.read = readchn,
+};
+
 static void *map_interface(domid_t domid)
 {
 	return xengnttab_map_grant_ref(*xgt_handle, domid,
@@ -389,7 +394,7 @@  static int new_domain(struct domain *domain, int port, bool restore)
 
 	domain->introduced = true;
 
-	domain->conn = new_connection(writechn, readchn);
+	domain->conn = new_connection(&domain_funcs);
 	if (!domain->conn)  {
 		errno = ENOMEM;
 		return errno;
@@ -1288,10 +1293,14 @@  void read_state_connection(const void *ctx, const void *state)
 	struct domain *domain, *tdomain;
 
 	if (sc->conn_type == XS_STATE_CONN_TYPE_SOCKET) {
-		conn = new_connection(writefd, readfd);
+#ifdef NO_SOCKETS
+		barf("socket based connection without sockets");
+#else
+		conn = new_connection(&socket_funcs);
 		if (!conn)
 			barf("error restoring connection");
 		conn->fd = sc->spec.socket_fd;
+#endif
 	} else {
 		domain = introduce_domain(ctx, sc->spec.ring.domid,
 					  sc->spec.ring.evtchn, true);