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hw/9pfs: Add support to use named socket for proxy FS

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Add option to use named socket for communicating between proxy helper
and qemu proxy FS. Access to socket can be given by using command line
options -u and -g.

Signed-off-by: M. Mohan Kumar <mohan@in.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
This commit is contained in:
M. Mohan Kumar 2011-12-14 13:58:47 +05:30 committed by Aneesh Kumar K.V
parent a2d8f1beb1
commit 84a87cc4cc
7 changed files with 159 additions and 17 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
fsdev/file-op-9p.h
View File

@ -57,6 +57,8 @@ typedef struct extended_ops {
*/
#define V9FS_SM_NONE 0x00000010
#define V9FS_RDONLY 0x00000020
#define V9FS_PROXY_SOCK_FD 0x00000040
#define V9FS_PROXY_SOCK_NAME 0x00000080
#define V9FS_SEC_MASK 0x0000001C

86
fsdev/virtfs-proxy-helper.c
View File

@ -57,6 +57,9 @@ static struct option helper_opts[] = {
{"fd", required_argument, NULL, 'f'},
{"path", required_argument, NULL, 'p'},
{"nodaemon", no_argument, NULL, 'n'},
{"socket", required_argument, NULL, 's'},
{"uid", required_argument, NULL, 'u'},
{"gid", required_argument, NULL, 'g'},
};
static bool is_daemon;
@ -695,11 +698,61 @@ err_out:
return ret;
}
/* create unix domain socket and return the descriptor */
static int proxy_socket(const char *path, uid_t uid, gid_t gid)
{
int sock, client;
struct sockaddr_un proxy, qemu;
socklen_t size;
/* requested socket already exists, refuse to start */
if (!access(path, F_OK)) {
do_log(LOG_CRIT, "socket already exists\n");
return -1;
}
sock = socket(AF_UNIX, SOCK_STREAM, 0);
if (sock < 0) {
do_perror("socket");
return -1;
}
/* mask other part of mode bits */
umask(7);
proxy.sun_family = AF_UNIX;
strcpy(proxy.sun_path, path);
if (bind(sock, (struct sockaddr *)&proxy,
sizeof(struct sockaddr_un)) < 0) {
do_perror("bind");
return -1;
}
if (chown(proxy.sun_path, uid, gid) < 0) {
do_perror("chown");
return -1;
}
if (listen(sock, 1) < 0) {
do_perror("listen");
return -1;
}
client = accept(sock, (struct sockaddr *)&qemu, &size);
if (client < 0) {
do_perror("accept");
return -1;
}
return client;
}
static void usage(char *prog)
{
fprintf(stderr, "usage: %s\n"
" -p|--path <path> 9p path to export\n"
" {-f|--fd <socket-descriptor>} socket file descriptor to be used\n"
" {-s|--socket <socketname> socket file used for communication\n"
" \t-u|--uid <uid> -g|--gid <gid>} - uid:gid combination to give "
" access to this socket\n"
" \tNote: -s & -f can not be used together\n"
" [-n|--nodaemon] Run as a normal program\n",
basename(prog));
}
@ -939,7 +992,10 @@ err_out:
int main(int argc, char **argv)
{
int sock;
uid_t own_u;
gid_t own_g;
char *rpath = NULL;
char *sock_name = NULL;
struct stat stbuf;
int c, option_index;
#ifdef FS_IOC_GETVERSION
@ -949,9 +1005,10 @@ int main(int argc, char **argv)
is_daemon = true;
sock = -1;
own_u = own_g = -1;
while (1) {
option_index = 0;
c = getopt_long(argc, argv, "p:nh?f:", helper_opts,
c = getopt_long(argc, argv, "p:nh?f:s:u:g:", helper_opts,
&option_index);
if (c == -1) {
break;
@ -966,6 +1023,15 @@ int main(int argc, char **argv)
case 'f':
sock = atoi(optarg);
break;
case 's':
sock_name = strdup(optarg);
break;
case 'u':
own_u = atoi(optarg);
break;
case 'g':
own_g = atoi(optarg);
break;
case '?':
case 'h':
default:
@ -975,8 +1041,16 @@ int main(int argc, char **argv)
}
/* Parameter validation */
if (sock == -1 || rpath == NULL) {
fprintf(stderr, "socket descriptor or path not specified\n");
if ((sock_name == NULL && sock == -1) || rpath == NULL) {
fprintf(stderr, "socket, socket descriptor or path not specified\n");
usage(argv[0]);
return -1;
}
if (*sock_name && (own_u == -1 || own_g == -1)) {
fprintf(stderr, "owner uid:gid not specified, ");
fprintf(stderr,
"owner uid:gid specifies who can access the socket file\n");
usage(argv[0]);
exit(EXIT_FAILURE);
}
@ -1001,6 +1075,12 @@ int main(int argc, char **argv)
}
do_log(LOG_INFO, "Started\n");
if (*sock_name) {
sock = proxy_socket(sock_name, own_u, own_g);
if (sock < 0) {
goto error;
}
}
get_version = false;
#ifdef FS_IOC_GETVERSION

4
fsdev/virtfs-proxy-helper.texi
View File

@ -46,6 +46,10 @@ Path to export for proxy filesystem driver
Use given file descriptor as socket descriptor for communicating with
qemu proxy fs drier. Usually a helper like libvirt will create
socketpair and pass one of the fds as parameter to -f|--fd
@item -s|--socket socket-file
Creates named socket file for communicating with qemu proxy fs driver
@item -u|--uid uid -g|--gid gid
uid:gid combination to give access to named socket file
@item -n|--nodaemon
Run as a normal program. By default program will run in daemon mode
@end table

56
hw/9pfs/virtio-9p-proxy.c
View File

@ -1095,15 +1095,49 @@ static int proxy_ioc_getversion(FsContext *fs_ctx, V9fsPath *path,
return err;
}
static int proxy_parse_opts(QemuOpts *opts, struct FsDriverEntry *fs)
static int connect_namedsocket(const char *path)
{
const char *sock_fd = qemu_opt_get(opts, "sock_fd");
int sockfd, size;
struct sockaddr_un helper;
if (sock_fd) {
fprintf(stderr, "sock_fd option not specified\n");
sockfd = socket(AF_UNIX, SOCK_STREAM, 0);
if (sockfd < 0) {
fprintf(stderr, "socket %s\n", strerror(errno));
return -1;
}
fs->path = g_strdup(sock_fd);
strcpy(helper.sun_path, path);
helper.sun_family = AF_UNIX;
size = strlen(helper.sun_path) + sizeof(helper.sun_family);
if (connect(sockfd, (struct sockaddr *)&helper, size) < 0) {
fprintf(stderr, "socket error\n");
return -1;
}
/* remove the socket for security reasons */
unlink(path);
return sockfd;
}
static int proxy_parse_opts(QemuOpts *opts, struct FsDriverEntry *fs)
{
const char *socket = qemu_opt_get(opts, "socket");
const char *sock_fd = qemu_opt_get(opts, "sock_fd");
if (!socket && !sock_fd) {
fprintf(stderr, "socket and sock_fd none of the option specified\n");
return -1;
}
if (socket && sock_fd) {
fprintf(stderr, "Both socket and sock_fd options specified\n");
return -1;
}
if (socket) {
fs->path = g_strdup(socket);
fs->export_flags = V9FS_PROXY_SOCK_NAME;
} else {
fs->path = g_strdup(sock_fd);
fs->export_flags = V9FS_PROXY_SOCK_FD;
}
return 0;
}
@ -1112,10 +1146,14 @@ static int proxy_init(FsContext *ctx)
V9fsProxy *proxy = g_malloc(sizeof(V9fsProxy));
int sock_id;
sock_id = atoi(ctx->fs_root);
if (sock_id < 0) {
fprintf(stderr, "socket descriptor not initialized\n");
return -1;
if (ctx->export_flags & V9FS_PROXY_SOCK_NAME) {
sock_id = connect_namedsocket(ctx->fs_root);
} else {
sock_id = atoi(ctx->fs_root);
if (sock_id < 0) {
fprintf(stderr, "socket descriptor not initialized\n");
return -1;
}
}
g_free(ctx->fs_root);

7
qemu-config.c
View File

@ -211,6 +211,10 @@ QemuOptsList qemu_fsdev_opts = {
}, {
.name = "readonly",
.type = QEMU_OPT_BOOL,
}, {
.name = "socket",
.type = QEMU_OPT_STRING,
}, {
.name = "sock_fd",
.type = QEMU_OPT_NUMBER,
@ -243,6 +247,9 @@ QemuOptsList qemu_virtfs_opts = {
}, {
.name = "readonly",
.type = QEMU_OPT_BOOL,
}, {
.name = "socket",
.type = QEMU_OPT_STRING,
}, {
.name = "sock_fd",
.type = QEMU_OPT_NUMBER,

15
qemu-options.hx
View File

@ -552,12 +552,12 @@ DEFHEADING(File system options:)
DEF("fsdev", HAS_ARG, QEMU_OPTION_fsdev,
"-fsdev fsdriver,id=id[,path=path,][security_model={mapped|passthrough|none}]\n"
" [,writeout=immediate][,readonly][,sock_fd=sock_fd]\n",
" [,writeout=immediate][,readonly][,socket=socket|sock_fd=sock_fd]\n",
QEMU_ARCH_ALL)
STEXI
@item -fsdev @var{fsdriver},id=@var{id},path=@var{path},[security_model=@var{security_model}][,writeout=@var{writeout}][,readonly][,sock_fd=@var{sock_fd}]
@item -fsdev @var{fsdriver},id=@var{id},path=@var{path},[security_model=@var{security_model}][,writeout=@var{writeout}][,readonly][,socket=@var{socket}|sock_fd=@var{sock_fd}]
@findex -fsdev
Define a new file system device. Valid options are:
@table @option
@ -590,6 +590,9 @@ reported as written by the storage subsystem.
@item readonly
Enables exporting 9p share as a readonly mount for guests. By default
read-write access is given.
@item socket=@var{socket}
Enables proxy filesystem driver to use passed socket file for communicating
with virtfs-proxy-helper
@item sock_fd=@var{sock_fd}
Enables proxy filesystem driver to use passed socket descriptor for
communicating with virtfs-proxy-helper. Usually a helper like libvirt
@ -614,12 +617,12 @@ DEFHEADING(Virtual File system pass-through options:)
DEF("virtfs", HAS_ARG, QEMU_OPTION_virtfs,
"-virtfs local,path=path,mount_tag=tag,security_model=[mapped|passthrough|none]\n"
" [,writeout=immediate][,readonly][,sock_fd=sock_fd]\n",
" [,writeout=immediate][,readonly][,socket=socket|sock_fd=sock_fd]\n",
QEMU_ARCH_ALL)
STEXI
@item -virtfs @var{fsdriver}[,path=@var{path}],mount_tag=@var{mount_tag}[,security_model=@var{security_model}][,writeout=@var{writeout}][,readonly][,sock_fd=@var{sock_fd}]
@item -virtfs @var{fsdriver}[,path=@var{path}],mount_tag=@var{mount_tag}[,security_model=@var{security_model}][,writeout=@var{writeout}][,readonly][,socket=@var{socket}|sock_fd=@var{sock_fd}]
@findex -virtfs
The general form of a Virtual File system pass-through options are:
@ -653,6 +656,10 @@ reported as written by the storage subsystem.
@item readonly
Enables exporting 9p share as a readonly mount for guests. By default
read-write access is given.
@item socket=@var{socket}
Enables proxy filesystem driver to use passed socket file for
communicating with virtfs-proxy-helper. Usually a helper like libvirt
will create socketpair and pass one of the fds as sock_fd
@item sock_fd
Enables proxy filesystem driver to use passed 'sock_fd' as the socket
descriptor for interfacing with virtfs-proxy-helper

6
vl.c
View File

@ -2661,7 +2661,7 @@ int main(int argc, char **argv, char **envp)
case QEMU_OPTION_virtfs: {
QemuOpts *fsdev;
QemuOpts *device;
const char *writeout, *sock_fd;
const char *writeout, *sock_fd, *socket;
olist = qemu_find_opts("virtfs");
if (!olist) {
@ -2701,6 +2701,10 @@ int main(int argc, char **argv, char **envp)
qemu_opt_set(fsdev, "path", qemu_opt_get(opts, "path"));
qemu_opt_set(fsdev, "security_model",
qemu_opt_get(opts, "security_model"));
socket = qemu_opt_get(opts, "socket");
if (socket) {
qemu_opt_set(fsdev, "socket", socket);
}
sock_fd = qemu_opt_get(opts, "sock_fd");
if (sock_fd) {
qemu_opt_set(fsdev, "sock_fd", sock_fd);