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passt: qemu patch for direct UNIX domain connection without the qrap wrapper

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...and, while at it, a second patch to fail when connect() fails in turn
with EINVAL. These two patches haven't been sent upstream yet.

Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
This commit is contained in:
Stefano Brivio 2021-03-17 10:57:45 +01:00
parent 1d807fc720
commit 8bfcc9208c
3 changed files with 213 additions and 1 deletions
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7
passt.c
View File

@ -562,7 +562,12 @@ listen:
listen(fd_unix, 1);
fprintf(stderr,
"You can now start qrap:\n\t"
"./qrap 5 kvm ... -net socket,fd=5 -net nic,model=virtio\n\n");
"./qrap 5 kvm ... -net socket,fd=5 -net nic,model=virtio\n"
"or directly qemu, patched with:\n\t"
"qemu/0001-net-Allow-also-UNIX-domain-sockets-to-be-used-as-net.patch\n"
"as follows:\n\t"
"kvm ... -net socket,connect="
UNIX_SOCK_PATH " -net nic,model=virtio\n\n");
c.fd_unix = accept(fd_unix, NULL, NULL);
ev.events = EPOLLIN | EPOLLET | EPOLLRDHUP | EPOLLERR | EPOLLHUP;

176
qemu/0001-net-Allow-also-UNIX-domain-sockets-to-be-used-as-net.patch Normal file
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@ -0,0 +1,176 @@
From 8876676bbdb108f51c372d1347dec1382078d702 Mon Sep 17 00:00:00 2001
From: Stefano Brivio <sbrivio@redhat.com>
Date: Wed, 17 Mar 2021 10:33:22 +0100
Subject: [PATCH 1/2] net: Allow also UNIX domain sockets to be used as -netdev
socket
It has lower overhead compared to TCP, doesn't need a free port
and the adaptation is trivial.
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
---
net/socket.c | 93 +++++++++++++++++++++++++++++++++++++++++--------
qemu-options.hx | 12 +++----
2 files changed, 84 insertions(+), 21 deletions(-)
diff --git a/net/socket.c b/net/socket.c
index c0de10c0c0..9d06953983 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -528,27 +528,62 @@ static int net_socket_listen_init(NetClientState *peer,
{
NetClientState *nc;
NetSocketState *s;
- struct sockaddr_in saddr;
- int fd, ret;
+ struct sockaddr_storage saddr;
+ struct sockaddr_in *saddr_in = (struct sockaddr_in *)&saddr;
+ struct sockaddr_un *saddr_un = (struct sockaddr_un *)&saddr;
+ size_t saddr_size;
+ int fd, ret, pf;
NetdevSocketOptions *stored;
- if (parse_host_port(&saddr, host_str, errp) < 0) {
- return -1;
+#ifndef WIN32
+ if (strchr(host_str, ':')) {
+#endif
+ if (parse_host_port(saddr_in, host_str, errp) < 0)
+ return -1;
+
+ pf = PF_INET;
+ saddr_size = sizeof(*saddr_in);
+#ifndef WIN32
+ } else {
+ struct stat sb;
+
+ if (stat(host_str, &sb) == -1) {
+ error_setg_errno(errp, errno, "can't stat socket path");
+ return -1;
+ }
+
+ if ((sb.st_mode & S_IFMT) != S_IFSOCK) {
+ error_setg_errno(errp, errno, "path provided is not a socket");
+ return -1;
+ }
+
+ saddr_un->sun_family = PF_UNIX;
+ strncpy(saddr_un->sun_path, host_str, sizeof(saddr_un->sun_path));
+
+ pf = PF_UNIX;
+ saddr_size = sizeof(*saddr_un);
}
+#endif /* !WIN32 */
- fd = qemu_socket(PF_INET, SOCK_STREAM, 0);
+ fd = qemu_socket(pf, SOCK_STREAM, 0);
if (fd < 0) {
error_setg_errno(errp, errno, "can't create stream socket");
return -1;
}
qemu_set_nonblock(fd);
- socket_set_fast_reuse(fd);
+ if (pf == PF_INET)
+ socket_set_fast_reuse(fd);
- ret = bind(fd, (struct sockaddr *)&saddr, sizeof(saddr));
+ ret = bind(fd, (struct sockaddr *)&saddr, saddr_size);
if (ret < 0) {
- error_setg_errno(errp, errno, "can't bind ip=%s to socket",
- inet_ntoa(saddr.sin_addr));
+ if (pf == PF_INET)
+ error_setg_errno(errp, errno, "can't bind ip=%s to socket",
+ inet_ntoa(saddr_in->sin_addr));
+ else if (pf == PF_UNIX)
+ error_setg_errno(errp, errno, "can't create socket with path: %s",
+ host_str);
+
closesocket(fd);
return -1;
}
@@ -586,15 +621,43 @@ static int net_socket_connect_init(NetClientState *peer,
Error **errp)
{
NetSocketState *s;
- int fd, connected, ret;
- struct sockaddr_in saddr;
+ int fd, connected, ret, pf;
+ struct sockaddr_storage saddr;
+ size_t saddr_size;
NetdevSocketOptions *stored;
- if (parse_host_port(&saddr, host_str, errp) < 0) {
- return -1;
+#ifndef WIN32
+ if (strchr(host_str, ':')) {
+#endif
+ if (parse_host_port((struct sockaddr_in *)&saddr, host_str, errp) < 0)
+ return -1;
+
+ pf = PF_INET;
+ saddr_size = sizeof(struct sockaddr_in);
+#ifndef WIN32
+ } else {
+ struct sockaddr_un *saddr_un = (struct sockaddr_un *)&saddr;
+ struct stat sb;
+
+ if (stat(host_str, &sb) == -1) {
+ error_setg_errno(errp, errno, "can't stat socket path");
+ return -1;
+ }
+
+ if ((sb.st_mode & S_IFMT) != S_IFSOCK) {
+ error_setg_errno(errp, errno, "provided path is not a socket");
+ return -1;
+ }
+
+ saddr_un->sun_family = PF_UNIX;
+ strncpy(saddr_un->sun_path, host_str, sizeof(saddr_un->sun_path));
+
+ pf = PF_UNIX;
+ saddr_size = sizeof(struct sockaddr_un);
}
+#endif /* !WIN32 */
- fd = qemu_socket(PF_INET, SOCK_STREAM, 0);
+ fd = qemu_socket(pf, SOCK_STREAM, 0);
if (fd < 0) {
error_setg_errno(errp, errno, "can't create stream socket");
return -1;
@@ -603,7 +666,7 @@ static int net_socket_connect_init(NetClientState *peer,
connected = 0;
for(;;) {
- ret = connect(fd, (struct sockaddr *)&saddr, sizeof(saddr));
+ ret = connect(fd, (struct sockaddr *)&saddr, saddr_size);
if (ret < 0) {
if (errno == EINTR || errno == EWOULDBLOCK) {
/* continue */
diff --git a/qemu-options.hx b/qemu-options.hx
index fe83ea09b2..b41351a54e 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -2836,13 +2836,13 @@ SRST
#connect a TAP device to bridge qemubr0
|qemu_system| linux.img -netdev bridge,br=qemubr0,id=n1 -device virtio-net,netdev=n1
-``-netdev socket,id=id[,fd=h][,listen=[host]:port][,connect=host:port]``
+``-netdev socket,id=id[,fd=h][,listen=[host]:port|path][,connect=host:port|path]``
This host network backend can be used to connect the guest's network
- to another QEMU virtual machine using a TCP socket connection. If
- ``listen`` is specified, QEMU waits for incoming connections on port
- (host is optional). ``connect`` is used to connect to another QEMU
- instance using the ``listen`` option. ``fd``\ =h specifies an
- already opened TCP socket.
+ to another QEMU virtual machine using a TCP or a UNIX domain socket
+ connection. If ``listen`` is specified, QEMU waits for incoming
+ connections on port (host is optional), or on path. ``connect`` is used
+ to connect to another QEMU instance using the ``listen`` option.
+ ``fd``\ =h specifies an already opened TCP or UNIX domain socket.
Example:
--
2.28.0

31
qemu/0002-net-Don-t-ignore-EINVAL-on-netdev-socket-connection.patch Normal file
View File

@ -0,0 +1,31 @@
From f4c9af4041754209eaad4f98041466b6f5e54902 Mon Sep 17 00:00:00 2001
From: Stefano Brivio <sbrivio@redhat.com>
Date: Wed, 17 Mar 2021 10:35:32 +0100
Subject: [PATCH 2/2] net: Don't ignore EINVAL on netdev socket connection
Other errors are treated as failure by net_socket_connect_init(),
but if connect() returns EINVAL, we'll fail silently. Remove the
related exception.
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
---
net/socket.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/net/socket.c b/net/socket.c
index 9d06953983..a7c10ea2b2 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -671,8 +671,7 @@ static int net_socket_connect_init(NetClientState *peer,
if (errno == EINTR || errno == EWOULDBLOCK) {
/* continue */
} else if (errno == EINPROGRESS ||
- errno == EALREADY ||
- errno == EINVAL) {
+ errno == EALREADY) {
break;
} else {
error_setg_errno(errp, errno, "can't connect socket");
--
2.28.0