From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:39308) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1S7jeT-0000EK-DU for qemu-devel@nongnu.org; Wed, 14 Mar 2012 04:33:46 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1S7je6-0002P0-81 for qemu-devel@nongnu.org; Wed, 14 Mar 2012 04:33:44 -0400 Received: from mx1.redhat.com ([209.132.183.28]:59800) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1S7je6-0002Op-00 for qemu-devel@nongnu.org; Wed, 14 Mar 2012 04:33:22 -0400 Message-ID: <4F6057CA.4010302@redhat.com> Date: Wed, 14 Mar 2012 16:33:14 +0800 From: Amos Kong MIME-Version: 1.0 References: <20120306224330.24264.9494.stgit@dhcp-8-167.nay.redhat.com> <20120306224745.24264.19990.stgit@dhcp-8-167.nay.redhat.com> <20120313163907.GB3699@illuin> In-Reply-To: <20120313163907.GB3699@illuin> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH v3 1/9] net: introduce tcp_server_start() List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Michael Roth Cc: aliguori@us.ibm.com, kvm@vger.kernel.org, quintela@redhat.com, jasowang@redhat.com, qemu-devel@nongnu.org, owasserm@redhat.com, laine@redhat.com On 14/03/12 00:39, Michael Roth wrote: > On Wed, Mar 07, 2012 at 06:47:45AM +0800, Amos Kong wrote: >> Introduce tcp_server_start() by moving original code in >> tcp_start_incoming_migration(). >> >> Signed-off-by: Amos Kong >> --- >> net.c | 28 ++++++++++++++++++++++++++++ >> qemu_socket.h | 2 ++ >> 2 files changed, 30 insertions(+), 0 deletions(-) >> >> diff --git a/net.c b/net.c >> index c34474f..e90ff23 100644 >> --- a/net.c >> +++ b/net.c >> @@ -99,6 +99,34 @@ static int get_str_sep(char *buf, int buf_size, const char **pp, int sep) >> return 0; >> } >> >> +int tcp_server_start(const char *str, int *fd) >> +{ >> + int val, ret; >> + struct sockaddr_in saddr; >> + >> + if (parse_host_port(&saddr, str)< 0) { >> + error_report("invalid host/port combination: %s", str); >> + return -EINVAL; >> + } >> + >> + *fd = qemu_socket(PF_INET, SOCK_STREAM, 0); >> + if (fd< 0) { >> + perror("socket"); >> + return -1; >> + } >> + socket_set_nonblock(*fd); >> + >> + /* allow fast reuse */ >> + val = 1; >> + setsockopt(*fd, SOL_SOCKET, SO_REUSEADDR, (const char *)&val, sizeof(val)); >> + >> + ret = bind(*fd, (struct sockaddr *)&saddr, sizeof(saddr)); >> + if (ret< 0) { >> + closesocket(*fd); >> + } >> + return ret; >> +} >> + > > I would combine this with patch 2, since it provides context for why > this function is being added. Would also do the same for 3 and 4. > > I see client the client implementation you need to pass fd back by > reference since ret can be set to EINPROGRESS/EWOULDBLOCK on success, ret restores 0 or -socket_error() success: 0, -EINPROGRESS fail : ret < 0 && ret !=-EINTR && ret != -EWOULDBLOCK , it should be -EINPROGRESS + ret = connect(*fd, (struct sockaddr *)&saddr, sizeof(saddr)); + if (ret < 0) { + ret = -socket_error(); + if (ret == -EINPROGRESS) { + break; > but here it looks like fd is only value if ret=0, so might as well just > pass back the fd as the function return value. Passed *fd tells us if socket creation success 'ret' would return 0 or -socket_error() -socket_error() is the error of socket creation/connection, it would be used by other functions. eg: migration-tcp.c: int tcp_start_incoming_migration( ... ret = tcp_server_start(host_port, &s); if (ret < 0) { fprintf(stderr, "tcp_server_start: %s\n", strerror(-ret)); We can also add a error msg in tcp_start_outgoing_migration() when tcp_client_start() fails. > Also, is there any reason we can't re-use > qemu-sockets.c:inet_listen()/qemu-sockets.c:inet_connect()? AFAICT they > serve the same purpose, and already include some of the work from your > PATCH #6. We could not directly use it, there are some difference, such as tcp_start_incoming_migration() doesn't set socket no-blocked, but net_socket_listen_init() sets socket no-blocked. There are some repeated code, so I write a tcp_common_start(), and use it in net_socket_listen_init()/ net_socket_connect_init() and tcp_start_incoming_migration()/ tcp_start_outgoing_migration() >> int parse_host_port(struct sockaddr_in *saddr, const char *str) >> { >> char buf[512]; >> diff --git a/qemu_socket.h b/qemu_socket.h >> index fe4cf6c..d612793 100644 >> --- a/qemu_socket.h >> +++ b/qemu_socket.h >> @@ -54,6 +54,8 @@ int unix_listen(const char *path, char *ostr, int olen); >> int unix_connect_opts(QemuOpts *opts); >> int unix_connect(const char *path); >> >> +int tcp_server_start(const char *str, int *fd); >> + >> /* Old, ipv4 only bits. Don't use for new code. */ >> int parse_host_port(struct sockaddr_in *saddr, const char *str); >> int socket_init(void); >> >> > -- Amos.