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-rw-r--r--qemu/hw/9pfs/9p-proxy.c1220
1 files changed, 1220 insertions, 0 deletions
diff --git a/qemu/hw/9pfs/9p-proxy.c b/qemu/hw/9pfs/9p-proxy.c
new file mode 100644
index 000000000..00a4eb2a7
--- /dev/null
+++ b/qemu/hw/9pfs/9p-proxy.c
@@ -0,0 +1,1220 @@
+/*
+ * 9p Proxy callback
+ *
+ * Copyright IBM, Corp. 2011
+ *
+ * Authors:
+ * M. Mohan Kumar <mohan@in.ibm.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2. See
+ * the COPYING file in the top-level directory.
+ */
+#include "qemu/osdep.h"
+#include <sys/socket.h>
+#include <sys/un.h>
+#include "9p.h"
+#include "qemu/cutils.h"
+#include "qemu/error-report.h"
+#include "fsdev/qemu-fsdev.h"
+#include "9p-proxy.h"
+
+typedef struct V9fsProxy {
+ int sockfd;
+ QemuMutex mutex;
+ struct iovec in_iovec;
+ struct iovec out_iovec;
+} V9fsProxy;
+
+/*
+ * Return received file descriptor on success in *status.
+ * errno is also returned on *status (which will be < 0)
+ * return < 0 on transport error.
+ */
+static int v9fs_receivefd(int sockfd, int *status)
+{
+ struct iovec iov;
+ struct msghdr msg;
+ struct cmsghdr *cmsg;
+ int retval, data, fd;
+ union MsgControl msg_control;
+
+ iov.iov_base = &data;
+ iov.iov_len = sizeof(data);
+
+ memset(&msg, 0, sizeof(msg));
+ msg.msg_iov = &iov;
+ msg.msg_iovlen = 1;
+ msg.msg_control = &msg_control;
+ msg.msg_controllen = sizeof(msg_control);
+
+ do {
+ retval = recvmsg(sockfd, &msg, 0);
+ } while (retval < 0 && errno == EINTR);
+ if (retval <= 0) {
+ return retval;
+ }
+ /*
+ * data is set to V9FS_FD_VALID, if ancillary data is sent. If this
+ * request doesn't need ancillary data (fd) or an error occurred,
+ * data is set to negative errno value.
+ */
+ if (data != V9FS_FD_VALID) {
+ *status = data;
+ return 0;
+ }
+ /*
+ * File descriptor (fd) is sent in the ancillary data. Check if we
+ * indeed received it. One of the reasons to fail to receive it is if
+ * we exceeded the maximum number of file descriptors!
+ */
+ for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
+ if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)) ||
+ cmsg->cmsg_level != SOL_SOCKET ||
+ cmsg->cmsg_type != SCM_RIGHTS) {
+ continue;
+ }
+ fd = *((int *)CMSG_DATA(cmsg));
+ *status = fd;
+ return 0;
+ }
+ *status = -ENFILE; /* Ancillary data sent but not received */
+ return 0;
+}
+
+static ssize_t socket_read(int sockfd, void *buff, size_t size)
+{
+ ssize_t retval, total = 0;
+
+ while (size) {
+ retval = read(sockfd, buff, size);
+ if (retval == 0) {
+ return -EIO;
+ }
+ if (retval < 0) {
+ if (errno == EINTR) {
+ continue;
+ }
+ return -errno;
+ }
+ size -= retval;
+ buff += retval;
+ total += retval;
+ }
+ return total;
+}
+
+/* Converts proxy_statfs to VFS statfs structure */
+static void prstatfs_to_statfs(struct statfs *stfs, ProxyStatFS *prstfs)
+{
+ memset(stfs, 0, sizeof(*stfs));
+ stfs->f_type = prstfs->f_type;
+ stfs->f_bsize = prstfs->f_bsize;
+ stfs->f_blocks = prstfs->f_blocks;
+ stfs->f_bfree = prstfs->f_bfree;
+ stfs->f_bavail = prstfs->f_bavail;
+ stfs->f_files = prstfs->f_files;
+ stfs->f_ffree = prstfs->f_ffree;
+ stfs->f_fsid.__val[0] = prstfs->f_fsid[0] & 0xFFFFFFFFU;
+ stfs->f_fsid.__val[1] = prstfs->f_fsid[1] >> 32 & 0xFFFFFFFFU;
+ stfs->f_namelen = prstfs->f_namelen;
+ stfs->f_frsize = prstfs->f_frsize;
+}
+
+/* Converts proxy_stat structure to VFS stat structure */
+static void prstat_to_stat(struct stat *stbuf, ProxyStat *prstat)
+{
+ memset(stbuf, 0, sizeof(*stbuf));
+ stbuf->st_dev = prstat->st_dev;
+ stbuf->st_ino = prstat->st_ino;
+ stbuf->st_nlink = prstat->st_nlink;
+ stbuf->st_mode = prstat->st_mode;
+ stbuf->st_uid = prstat->st_uid;
+ stbuf->st_gid = prstat->st_gid;
+ stbuf->st_rdev = prstat->st_rdev;
+ stbuf->st_size = prstat->st_size;
+ stbuf->st_blksize = prstat->st_blksize;
+ stbuf->st_blocks = prstat->st_blocks;
+ stbuf->st_atim.tv_sec = prstat->st_atim_sec;
+ stbuf->st_atim.tv_nsec = prstat->st_atim_nsec;
+ stbuf->st_mtime = prstat->st_mtim_sec;
+ stbuf->st_mtim.tv_nsec = prstat->st_mtim_nsec;
+ stbuf->st_ctime = prstat->st_ctim_sec;
+ stbuf->st_ctim.tv_nsec = prstat->st_ctim_nsec;
+}
+
+/*
+ * Response contains two parts
+ * {header, data}
+ * header.type == T_ERROR, data -> -errno
+ * header.type == T_SUCCESS, data -> response
+ * size of errno/response is given by header.size
+ * returns < 0, on transport error. response is
+ * valid only if status >= 0.
+ */
+static int v9fs_receive_response(V9fsProxy *proxy, int type,
+ int *status, void *response)
+{
+ int retval;
+ ProxyHeader header;
+ struct iovec *reply = &proxy->in_iovec;
+
+ *status = 0;
+ reply->iov_len = 0;
+ retval = socket_read(proxy->sockfd, reply->iov_base, PROXY_HDR_SZ);
+ if (retval < 0) {
+ return retval;
+ }
+ reply->iov_len = PROXY_HDR_SZ;
+ proxy_unmarshal(reply, 0, "dd", &header.type, &header.size);
+ /*
+ * if response size > PROXY_MAX_IO_SZ, read the response but ignore it and
+ * return -ENOBUFS
+ */
+ if (header.size > PROXY_MAX_IO_SZ) {
+ int count;
+ while (header.size > 0) {
+ count = MIN(PROXY_MAX_IO_SZ, header.size);
+ count = socket_read(proxy->sockfd, reply->iov_base, count);
+ if (count < 0) {
+ return count;
+ }
+ header.size -= count;
+ }
+ *status = -ENOBUFS;
+ return 0;
+ }
+
+ retval = socket_read(proxy->sockfd,
+ reply->iov_base + PROXY_HDR_SZ, header.size);
+ if (retval < 0) {
+ return retval;
+ }
+ reply->iov_len += header.size;
+ /* there was an error during processing request */
+ if (header.type == T_ERROR) {
+ int ret;
+ ret = proxy_unmarshal(reply, PROXY_HDR_SZ, "d", status);
+ if (ret < 0) {
+ *status = ret;
+ }
+ return 0;
+ }
+
+ switch (type) {
+ case T_LSTAT: {
+ ProxyStat prstat;
+ retval = proxy_unmarshal(reply, PROXY_HDR_SZ,
+ "qqqdddqqqqqqqqqq", &prstat.st_dev,
+ &prstat.st_ino, &prstat.st_nlink,
+ &prstat.st_mode, &prstat.st_uid,
+ &prstat.st_gid, &prstat.st_rdev,
+ &prstat.st_size, &prstat.st_blksize,
+ &prstat.st_blocks,
+ &prstat.st_atim_sec, &prstat.st_atim_nsec,
+ &prstat.st_mtim_sec, &prstat.st_mtim_nsec,
+ &prstat.st_ctim_sec, &prstat.st_ctim_nsec);
+ prstat_to_stat(response, &prstat);
+ break;
+ }
+ case T_STATFS: {
+ ProxyStatFS prstfs;
+ retval = proxy_unmarshal(reply, PROXY_HDR_SZ,
+ "qqqqqqqqqqq", &prstfs.f_type,
+ &prstfs.f_bsize, &prstfs.f_blocks,
+ &prstfs.f_bfree, &prstfs.f_bavail,
+ &prstfs.f_files, &prstfs.f_ffree,
+ &prstfs.f_fsid[0], &prstfs.f_fsid[1],
+ &prstfs.f_namelen, &prstfs.f_frsize);
+ prstatfs_to_statfs(response, &prstfs);
+ break;
+ }
+ case T_READLINK: {
+ V9fsString target;
+ v9fs_string_init(&target);
+ retval = proxy_unmarshal(reply, PROXY_HDR_SZ, "s", &target);
+ strcpy(response, target.data);
+ v9fs_string_free(&target);
+ break;
+ }
+ case T_LGETXATTR:
+ case T_LLISTXATTR: {
+ V9fsString xattr;
+ v9fs_string_init(&xattr);
+ retval = proxy_unmarshal(reply, PROXY_HDR_SZ, "s", &xattr);
+ memcpy(response, xattr.data, xattr.size);
+ v9fs_string_free(&xattr);
+ break;
+ }
+ case T_GETVERSION:
+ proxy_unmarshal(reply, PROXY_HDR_SZ, "q", response);
+ break;
+ default:
+ return -1;
+ }
+ if (retval < 0) {
+ *status = retval;
+ }
+ return 0;
+}
+
+/*
+ * return < 0 on transport error.
+ * *status is valid only if return >= 0
+ */
+static int v9fs_receive_status(V9fsProxy *proxy,
+ struct iovec *reply, int *status)
+{
+ int retval;
+ ProxyHeader header;
+
+ *status = 0;
+ reply->iov_len = 0;
+ retval = socket_read(proxy->sockfd, reply->iov_base, PROXY_HDR_SZ);
+ if (retval < 0) {
+ return retval;
+ }
+ reply->iov_len = PROXY_HDR_SZ;
+ proxy_unmarshal(reply, 0, "dd", &header.type, &header.size);
+ if (header.size != sizeof(int)) {
+ *status = -ENOBUFS;
+ return 0;
+ }
+ retval = socket_read(proxy->sockfd,
+ reply->iov_base + PROXY_HDR_SZ, header.size);
+ if (retval < 0) {
+ return retval;
+ }
+ reply->iov_len += header.size;
+ proxy_unmarshal(reply, PROXY_HDR_SZ, "d", status);
+ return 0;
+}
+
+/*
+ * Proxy->header and proxy->request written to socket by QEMU process.
+ * This request read by proxy helper process
+ * returns 0 on success and -errno on error
+ */
+static int v9fs_request(V9fsProxy *proxy, int type,
+ void *response, const char *fmt, ...)
+{
+ dev_t rdev;
+ va_list ap;
+ int size = 0;
+ int retval = 0;
+ uint64_t offset;
+ ProxyHeader header = { 0, 0};
+ struct timespec spec[2];
+ int flags, mode, uid, gid;
+ V9fsString *name, *value;
+ V9fsString *path, *oldpath;
+ struct iovec *iovec = NULL, *reply = NULL;
+
+ qemu_mutex_lock(&proxy->mutex);
+
+ if (proxy->sockfd == -1) {
+ retval = -EIO;
+ goto err_out;
+ }
+ iovec = &proxy->out_iovec;
+ reply = &proxy->in_iovec;
+ va_start(ap, fmt);
+ switch (type) {
+ case T_OPEN:
+ path = va_arg(ap, V9fsString *);
+ flags = va_arg(ap, int);
+ retval = proxy_marshal(iovec, PROXY_HDR_SZ, "sd", path, flags);
+ if (retval > 0) {
+ header.size = retval;
+ header.type = T_OPEN;
+ }
+ break;
+ case T_CREATE:
+ path = va_arg(ap, V9fsString *);
+ flags = va_arg(ap, int);
+ mode = va_arg(ap, int);
+ uid = va_arg(ap, int);
+ gid = va_arg(ap, int);
+ retval = proxy_marshal(iovec, PROXY_HDR_SZ, "sdddd", path,
+ flags, mode, uid, gid);
+ if (retval > 0) {
+ header.size = retval;
+ header.type = T_CREATE;
+ }
+ break;
+ case T_MKNOD:
+ path = va_arg(ap, V9fsString *);
+ mode = va_arg(ap, int);
+ rdev = va_arg(ap, long int);
+ uid = va_arg(ap, int);
+ gid = va_arg(ap, int);
+ retval = proxy_marshal(iovec, PROXY_HDR_SZ, "ddsdq",
+ uid, gid, path, mode, rdev);
+ if (retval > 0) {
+ header.size = retval;
+ header.type = T_MKNOD;
+ }
+ break;
+ case T_MKDIR:
+ path = va_arg(ap, V9fsString *);
+ mode = va_arg(ap, int);
+ uid = va_arg(ap, int);
+ gid = va_arg(ap, int);
+ retval = proxy_marshal(iovec, PROXY_HDR_SZ, "ddsd",
+ uid, gid, path, mode);
+ if (retval > 0) {
+ header.size = retval;
+ header.type = T_MKDIR;
+ }
+ break;
+ case T_SYMLINK:
+ oldpath = va_arg(ap, V9fsString *);
+ path = va_arg(ap, V9fsString *);
+ uid = va_arg(ap, int);
+ gid = va_arg(ap, int);
+ retval = proxy_marshal(iovec, PROXY_HDR_SZ, "ddss",
+ uid, gid, oldpath, path);
+ if (retval > 0) {
+ header.size = retval;
+ header.type = T_SYMLINK;
+ }
+ break;
+ case T_LINK:
+ oldpath = va_arg(ap, V9fsString *);
+ path = va_arg(ap, V9fsString *);
+ retval = proxy_marshal(iovec, PROXY_HDR_SZ, "ss",
+ oldpath, path);
+ if (retval > 0) {
+ header.size = retval;
+ header.type = T_LINK;
+ }
+ break;
+ case T_LSTAT:
+ path = va_arg(ap, V9fsString *);
+ retval = proxy_marshal(iovec, PROXY_HDR_SZ, "s", path);
+ if (retval > 0) {
+ header.size = retval;
+ header.type = T_LSTAT;
+ }
+ break;
+ case T_READLINK:
+ path = va_arg(ap, V9fsString *);
+ size = va_arg(ap, int);
+ retval = proxy_marshal(iovec, PROXY_HDR_SZ, "sd", path, size);
+ if (retval > 0) {
+ header.size = retval;
+ header.type = T_READLINK;
+ }
+ break;
+ case T_STATFS:
+ path = va_arg(ap, V9fsString *);
+ retval = proxy_marshal(iovec, PROXY_HDR_SZ, "s", path);
+ if (retval > 0) {
+ header.size = retval;
+ header.type = T_STATFS;
+ }
+ break;
+ case T_CHMOD:
+ path = va_arg(ap, V9fsString *);
+ mode = va_arg(ap, int);
+ retval = proxy_marshal(iovec, PROXY_HDR_SZ, "sd", path, mode);
+ if (retval > 0) {
+ header.size = retval;
+ header.type = T_CHMOD;
+ }
+ break;
+ case T_CHOWN:
+ path = va_arg(ap, V9fsString *);
+ uid = va_arg(ap, int);
+ gid = va_arg(ap, int);
+ retval = proxy_marshal(iovec, PROXY_HDR_SZ, "sdd", path, uid, gid);
+ if (retval > 0) {
+ header.size = retval;
+ header.type = T_CHOWN;
+ }
+ break;
+ case T_TRUNCATE:
+ path = va_arg(ap, V9fsString *);
+ offset = va_arg(ap, uint64_t);
+ retval = proxy_marshal(iovec, PROXY_HDR_SZ, "sq", path, offset);
+ if (retval > 0) {
+ header.size = retval;
+ header.type = T_TRUNCATE;
+ }
+ break;
+ case T_UTIME:
+ path = va_arg(ap, V9fsString *);
+ spec[0].tv_sec = va_arg(ap, long);
+ spec[0].tv_nsec = va_arg(ap, long);
+ spec[1].tv_sec = va_arg(ap, long);
+ spec[1].tv_nsec = va_arg(ap, long);
+ retval = proxy_marshal(iovec, PROXY_HDR_SZ, "sqqqq", path,
+ spec[0].tv_sec, spec[1].tv_nsec,
+ spec[1].tv_sec, spec[1].tv_nsec);
+ if (retval > 0) {
+ header.size = retval;
+ header.type = T_UTIME;
+ }
+ break;
+ case T_RENAME:
+ oldpath = va_arg(ap, V9fsString *);
+ path = va_arg(ap, V9fsString *);
+ retval = proxy_marshal(iovec, PROXY_HDR_SZ, "ss", oldpath, path);
+ if (retval > 0) {
+ header.size = retval;
+ header.type = T_RENAME;
+ }
+ break;
+ case T_REMOVE:
+ path = va_arg(ap, V9fsString *);
+ retval = proxy_marshal(iovec, PROXY_HDR_SZ, "s", path);
+ if (retval > 0) {
+ header.size = retval;
+ header.type = T_REMOVE;
+ }
+ break;
+ case T_LGETXATTR:
+ size = va_arg(ap, int);
+ path = va_arg(ap, V9fsString *);
+ name = va_arg(ap, V9fsString *);
+ retval = proxy_marshal(iovec, PROXY_HDR_SZ,
+ "dss", size, path, name);
+ if (retval > 0) {
+ header.size = retval;
+ header.type = T_LGETXATTR;
+ }
+ break;
+ case T_LLISTXATTR:
+ size = va_arg(ap, int);
+ path = va_arg(ap, V9fsString *);
+ retval = proxy_marshal(iovec, PROXY_HDR_SZ, "ds", size, path);
+ if (retval > 0) {
+ header.size = retval;
+ header.type = T_LLISTXATTR;
+ }
+ break;
+ case T_LSETXATTR:
+ path = va_arg(ap, V9fsString *);
+ name = va_arg(ap, V9fsString *);
+ value = va_arg(ap, V9fsString *);
+ size = va_arg(ap, int);
+ flags = va_arg(ap, int);
+ retval = proxy_marshal(iovec, PROXY_HDR_SZ, "sssdd",
+ path, name, value, size, flags);
+ if (retval > 0) {
+ header.size = retval;
+ header.type = T_LSETXATTR;
+ }
+ break;
+ case T_LREMOVEXATTR:
+ path = va_arg(ap, V9fsString *);
+ name = va_arg(ap, V9fsString *);
+ retval = proxy_marshal(iovec, PROXY_HDR_SZ, "ss", path, name);
+ if (retval > 0) {
+ header.size = retval;
+ header.type = T_LREMOVEXATTR;
+ }
+ break;
+ case T_GETVERSION:
+ path = va_arg(ap, V9fsString *);
+ retval = proxy_marshal(iovec, PROXY_HDR_SZ, "s", path);
+ if (retval > 0) {
+ header.size = retval;
+ header.type = T_GETVERSION;
+ }
+ break;
+ default:
+ error_report("Invalid type %d", type);
+ retval = -EINVAL;
+ break;
+ }
+ va_end(ap);
+
+ if (retval < 0) {
+ goto err_out;
+ }
+
+ /* marshal the header details */
+ proxy_marshal(iovec, 0, "dd", header.type, header.size);
+ header.size += PROXY_HDR_SZ;
+
+ retval = qemu_write_full(proxy->sockfd, iovec->iov_base, header.size);
+ if (retval != header.size) {
+ goto close_error;
+ }
+
+ switch (type) {
+ case T_OPEN:
+ case T_CREATE:
+ /*
+ * A file descriptor is returned as response for
+ * T_OPEN,T_CREATE on success
+ */
+ if (v9fs_receivefd(proxy->sockfd, &retval) < 0) {
+ goto close_error;
+ }
+ break;
+ case T_MKNOD:
+ case T_MKDIR:
+ case T_SYMLINK:
+ case T_LINK:
+ case T_CHMOD:
+ case T_CHOWN:
+ case T_RENAME:
+ case T_TRUNCATE:
+ case T_UTIME:
+ case T_REMOVE:
+ case T_LSETXATTR:
+ case T_LREMOVEXATTR:
+ if (v9fs_receive_status(proxy, reply, &retval) < 0) {
+ goto close_error;
+ }
+ break;
+ case T_LSTAT:
+ case T_READLINK:
+ case T_STATFS:
+ case T_GETVERSION:
+ if (v9fs_receive_response(proxy, type, &retval, response) < 0) {
+ goto close_error;
+ }
+ break;
+ case T_LGETXATTR:
+ case T_LLISTXATTR:
+ if (!size) {
+ if (v9fs_receive_status(proxy, reply, &retval) < 0) {
+ goto close_error;
+ }
+ } else {
+ if (v9fs_receive_response(proxy, type, &retval, response) < 0) {
+ goto close_error;
+ }
+ }
+ break;
+ }
+
+err_out:
+ qemu_mutex_unlock(&proxy->mutex);
+ return retval;
+
+close_error:
+ close(proxy->sockfd);
+ proxy->sockfd = -1;
+ qemu_mutex_unlock(&proxy->mutex);
+ return -EIO;
+}
+
+static int proxy_lstat(FsContext *fs_ctx, V9fsPath *fs_path, struct stat *stbuf)
+{
+ int retval;
+ retval = v9fs_request(fs_ctx->private, T_LSTAT, stbuf, "s", fs_path);
+ if (retval < 0) {
+ errno = -retval;
+ return -1;
+ }
+ return retval;
+}
+
+static ssize_t proxy_readlink(FsContext *fs_ctx, V9fsPath *fs_path,
+ char *buf, size_t bufsz)
+{
+ int retval;
+ retval = v9fs_request(fs_ctx->private, T_READLINK, buf, "sd",
+ fs_path, bufsz);
+ if (retval < 0) {
+ errno = -retval;
+ return -1;
+ }
+ return strlen(buf);
+}
+
+static int proxy_close(FsContext *ctx, V9fsFidOpenState *fs)
+{
+ return close(fs->fd);
+}
+
+static int proxy_closedir(FsContext *ctx, V9fsFidOpenState *fs)
+{
+ return closedir(fs->dir);
+}
+
+static int proxy_open(FsContext *ctx, V9fsPath *fs_path,
+ int flags, V9fsFidOpenState *fs)
+{
+ fs->fd = v9fs_request(ctx->private, T_OPEN, NULL, "sd", fs_path, flags);
+ if (fs->fd < 0) {
+ errno = -fs->fd;
+ fs->fd = -1;
+ }
+ return fs->fd;
+}
+
+static int proxy_opendir(FsContext *ctx,
+ V9fsPath *fs_path, V9fsFidOpenState *fs)
+{
+ int serrno, fd;
+
+ fs->dir = NULL;
+ fd = v9fs_request(ctx->private, T_OPEN, NULL, "sd", fs_path, O_DIRECTORY);
+ if (fd < 0) {
+ errno = -fd;
+ return -1;
+ }
+ fs->dir = fdopendir(fd);
+ if (!fs->dir) {
+ serrno = errno;
+ close(fd);
+ errno = serrno;
+ return -1;
+ }
+ return 0;
+}
+
+static void proxy_rewinddir(FsContext *ctx, V9fsFidOpenState *fs)
+{
+ rewinddir(fs->dir);
+}
+
+static off_t proxy_telldir(FsContext *ctx, V9fsFidOpenState *fs)
+{
+ return telldir(fs->dir);
+}
+
+static int proxy_readdir_r(FsContext *ctx, V9fsFidOpenState *fs,
+ struct dirent *entry,
+ struct dirent **result)
+{
+ return readdir_r(fs->dir, entry, result);
+}
+
+static void proxy_seekdir(FsContext *ctx, V9fsFidOpenState *fs, off_t off)
+{
+ seekdir(fs->dir, off);
+}
+
+static ssize_t proxy_preadv(FsContext *ctx, V9fsFidOpenState *fs,
+ const struct iovec *iov,
+ int iovcnt, off_t offset)
+{
+ ssize_t ret;
+#ifdef CONFIG_PREADV
+ ret = preadv(fs->fd, iov, iovcnt, offset);
+#else
+ ret = lseek(fs->fd, offset, SEEK_SET);
+ if (ret >= 0) {
+ ret = readv(fs->fd, iov, iovcnt);
+ }
+#endif
+ return ret;
+}
+
+static ssize_t proxy_pwritev(FsContext *ctx, V9fsFidOpenState *fs,
+ const struct iovec *iov,
+ int iovcnt, off_t offset)
+{
+ ssize_t ret;
+
+#ifdef CONFIG_PREADV
+ ret = pwritev(fs->fd, iov, iovcnt, offset);
+#else
+ ret = lseek(fs->fd, offset, SEEK_SET);
+ if (ret >= 0) {
+ ret = writev(fs->fd, iov, iovcnt);
+ }
+#endif
+#ifdef CONFIG_SYNC_FILE_RANGE
+ if (ret > 0 && ctx->export_flags & V9FS_IMMEDIATE_WRITEOUT) {
+ /*
+ * Initiate a writeback. This is not a data integrity sync.
+ * We want to ensure that we don't leave dirty pages in the cache
+ * after write when writeout=immediate is sepcified.
+ */
+ sync_file_range(fs->fd, offset, ret,
+ SYNC_FILE_RANGE_WAIT_BEFORE | SYNC_FILE_RANGE_WRITE);
+ }
+#endif
+ return ret;
+}
+
+static int proxy_chmod(FsContext *fs_ctx, V9fsPath *fs_path, FsCred *credp)
+{
+ int retval;
+ retval = v9fs_request(fs_ctx->private, T_CHMOD, NULL, "sd",
+ fs_path, credp->fc_mode);
+ if (retval < 0) {
+ errno = -retval;
+ }
+ return retval;
+}
+
+static int proxy_mknod(FsContext *fs_ctx, V9fsPath *dir_path,
+ const char *name, FsCred *credp)
+{
+ int retval;
+ V9fsString fullname;
+
+ v9fs_string_init(&fullname);
+ v9fs_string_sprintf(&fullname, "%s/%s", dir_path->data, name);
+
+ retval = v9fs_request(fs_ctx->private, T_MKNOD, NULL, "sdqdd",
+ &fullname, credp->fc_mode, credp->fc_rdev,
+ credp->fc_uid, credp->fc_gid);
+ v9fs_string_free(&fullname);
+ if (retval < 0) {
+ errno = -retval;
+ retval = -1;
+ }
+ return retval;
+}
+
+static int proxy_mkdir(FsContext *fs_ctx, V9fsPath *dir_path,
+ const char *name, FsCred *credp)
+{
+ int retval;
+ V9fsString fullname;
+
+ v9fs_string_init(&fullname);
+ v9fs_string_sprintf(&fullname, "%s/%s", dir_path->data, name);
+
+ retval = v9fs_request(fs_ctx->private, T_MKDIR, NULL, "sddd", &fullname,
+ credp->fc_mode, credp->fc_uid, credp->fc_gid);
+ v9fs_string_free(&fullname);
+ if (retval < 0) {
+ errno = -retval;
+ retval = -1;
+ }
+ v9fs_string_free(&fullname);
+ return retval;
+}
+
+static int proxy_fstat(FsContext *fs_ctx, int fid_type,
+ V9fsFidOpenState *fs, struct stat *stbuf)
+{
+ int fd;
+
+ if (fid_type == P9_FID_DIR) {
+ fd = dirfd(fs->dir);
+ } else {
+ fd = fs->fd;
+ }
+ return fstat(fd, stbuf);
+}
+
+static int proxy_open2(FsContext *fs_ctx, V9fsPath *dir_path, const char *name,
+ int flags, FsCred *credp, V9fsFidOpenState *fs)
+{
+ V9fsString fullname;
+
+ v9fs_string_init(&fullname);
+ v9fs_string_sprintf(&fullname, "%s/%s", dir_path->data, name);
+
+ fs->fd = v9fs_request(fs_ctx->private, T_CREATE, NULL, "sdddd",
+ &fullname, flags, credp->fc_mode,
+ credp->fc_uid, credp->fc_gid);
+ v9fs_string_free(&fullname);
+ if (fs->fd < 0) {
+ errno = -fs->fd;
+ fs->fd = -1;
+ }
+ return fs->fd;
+}
+
+static int proxy_symlink(FsContext *fs_ctx, const char *oldpath,
+ V9fsPath *dir_path, const char *name, FsCred *credp)
+{
+ int retval;
+ V9fsString fullname, target;
+
+ v9fs_string_init(&fullname);
+ v9fs_string_init(&target);
+
+ v9fs_string_sprintf(&fullname, "%s/%s", dir_path->data, name);
+ v9fs_string_sprintf(&target, "%s", oldpath);
+
+ retval = v9fs_request(fs_ctx->private, T_SYMLINK, NULL, "ssdd",
+ &target, &fullname, credp->fc_uid, credp->fc_gid);
+ v9fs_string_free(&fullname);
+ v9fs_string_free(&target);
+ if (retval < 0) {
+ errno = -retval;
+ retval = -1;
+ }
+ return retval;
+}
+
+static int proxy_link(FsContext *ctx, V9fsPath *oldpath,
+ V9fsPath *dirpath, const char *name)
+{
+ int retval;
+ V9fsString newpath;
+
+ v9fs_string_init(&newpath);
+ v9fs_string_sprintf(&newpath, "%s/%s", dirpath->data, name);
+
+ retval = v9fs_request(ctx->private, T_LINK, NULL, "ss", oldpath, &newpath);
+ v9fs_string_free(&newpath);
+ if (retval < 0) {
+ errno = -retval;
+ retval = -1;
+ }
+ return retval;
+}
+
+static int proxy_truncate(FsContext *ctx, V9fsPath *fs_path, off_t size)
+{
+ int retval;
+
+ retval = v9fs_request(ctx->private, T_TRUNCATE, NULL, "sq", fs_path, size);
+ if (retval < 0) {
+ errno = -retval;
+ return -1;
+ }
+ return 0;
+}
+
+static int proxy_rename(FsContext *ctx, const char *oldpath,
+ const char *newpath)
+{
+ int retval;
+ V9fsString oldname, newname;
+
+ v9fs_string_init(&oldname);
+ v9fs_string_init(&newname);
+
+ v9fs_string_sprintf(&oldname, "%s", oldpath);
+ v9fs_string_sprintf(&newname, "%s", newpath);
+ retval = v9fs_request(ctx->private, T_RENAME, NULL, "ss",
+ &oldname, &newname);
+ v9fs_string_free(&oldname);
+ v9fs_string_free(&newname);
+ if (retval < 0) {
+ errno = -retval;
+ }
+ return retval;
+}
+
+static int proxy_chown(FsContext *fs_ctx, V9fsPath *fs_path, FsCred *credp)
+{
+ int retval;
+ retval = v9fs_request(fs_ctx->private, T_CHOWN, NULL, "sdd",
+ fs_path, credp->fc_uid, credp->fc_gid);
+ if (retval < 0) {
+ errno = -retval;
+ }
+ return retval;
+}
+
+static int proxy_utimensat(FsContext *s, V9fsPath *fs_path,
+ const struct timespec *buf)
+{
+ int retval;
+ retval = v9fs_request(s->private, T_UTIME, NULL, "sqqqq",
+ fs_path,
+ buf[0].tv_sec, buf[0].tv_nsec,
+ buf[1].tv_sec, buf[1].tv_nsec);
+ if (retval < 0) {
+ errno = -retval;
+ }
+ return retval;
+}
+
+static int proxy_remove(FsContext *ctx, const char *path)
+{
+ int retval;
+ V9fsString name;
+ v9fs_string_init(&name);
+ v9fs_string_sprintf(&name, "%s", path);
+ retval = v9fs_request(ctx->private, T_REMOVE, NULL, "s", &name);
+ v9fs_string_free(&name);
+ if (retval < 0) {
+ errno = -retval;
+ }
+ return retval;
+}
+
+static int proxy_fsync(FsContext *ctx, int fid_type,
+ V9fsFidOpenState *fs, int datasync)
+{
+ int fd;
+
+ if (fid_type == P9_FID_DIR) {
+ fd = dirfd(fs->dir);
+ } else {
+ fd = fs->fd;
+ }
+
+ if (datasync) {
+ return qemu_fdatasync(fd);
+ } else {
+ return fsync(fd);
+ }
+}
+
+static int proxy_statfs(FsContext *s, V9fsPath *fs_path, struct statfs *stbuf)
+{
+ int retval;
+ retval = v9fs_request(s->private, T_STATFS, stbuf, "s", fs_path);
+ if (retval < 0) {
+ errno = -retval;
+ return -1;
+ }
+ return retval;
+}
+
+static ssize_t proxy_lgetxattr(FsContext *ctx, V9fsPath *fs_path,
+ const char *name, void *value, size_t size)
+{
+ int retval;
+ V9fsString xname;
+
+ v9fs_string_init(&xname);
+ v9fs_string_sprintf(&xname, "%s", name);
+ retval = v9fs_request(ctx->private, T_LGETXATTR, value, "dss", size,
+ fs_path, &xname);
+ v9fs_string_free(&xname);
+ if (retval < 0) {
+ errno = -retval;
+ }
+ return retval;
+}
+
+static ssize_t proxy_llistxattr(FsContext *ctx, V9fsPath *fs_path,
+ void *value, size_t size)
+{
+ int retval;
+ retval = v9fs_request(ctx->private, T_LLISTXATTR, value, "ds", size,
+ fs_path);
+ if (retval < 0) {
+ errno = -retval;
+ }
+ return retval;
+}
+
+static int proxy_lsetxattr(FsContext *ctx, V9fsPath *fs_path, const char *name,
+ void *value, size_t size, int flags)
+{
+ int retval;
+ V9fsString xname, xvalue;
+
+ v9fs_string_init(&xname);
+ v9fs_string_sprintf(&xname, "%s", name);
+
+ v9fs_string_init(&xvalue);
+ xvalue.size = size;
+ xvalue.data = g_malloc(size);
+ memcpy(xvalue.data, value, size);
+
+ retval = v9fs_request(ctx->private, T_LSETXATTR, value, "sssdd",
+ fs_path, &xname, &xvalue, size, flags);
+ v9fs_string_free(&xname);
+ v9fs_string_free(&xvalue);
+ if (retval < 0) {
+ errno = -retval;
+ }
+ return retval;
+}
+
+static int proxy_lremovexattr(FsContext *ctx, V9fsPath *fs_path,
+ const char *name)
+{
+ int retval;
+ V9fsString xname;
+
+ v9fs_string_init(&xname);
+ v9fs_string_sprintf(&xname, "%s", name);
+ retval = v9fs_request(ctx->private, T_LREMOVEXATTR, NULL, "ss",
+ fs_path, &xname);
+ v9fs_string_free(&xname);
+ if (retval < 0) {
+ errno = -retval;
+ }
+ return retval;
+}
+
+static int proxy_name_to_path(FsContext *ctx, V9fsPath *dir_path,
+ const char *name, V9fsPath *target)
+{
+ if (dir_path) {
+ v9fs_string_sprintf((V9fsString *)target, "%s/%s",
+ dir_path->data, name);
+ } else {
+ v9fs_string_sprintf((V9fsString *)target, "%s", name);
+ }
+ /* Bump the size for including terminating NULL */
+ target->size++;
+ return 0;
+}
+
+static int proxy_renameat(FsContext *ctx, V9fsPath *olddir,
+ const char *old_name, V9fsPath *newdir,
+ const char *new_name)
+{
+ int ret;
+ V9fsString old_full_name, new_full_name;
+
+ v9fs_string_init(&old_full_name);
+ v9fs_string_init(&new_full_name);
+
+ v9fs_string_sprintf(&old_full_name, "%s/%s", olddir->data, old_name);
+ v9fs_string_sprintf(&new_full_name, "%s/%s", newdir->data, new_name);
+
+ ret = proxy_rename(ctx, old_full_name.data, new_full_name.data);
+ v9fs_string_free(&old_full_name);
+ v9fs_string_free(&new_full_name);
+ return ret;
+}
+
+static int proxy_unlinkat(FsContext *ctx, V9fsPath *dir,
+ const char *name, int flags)
+{
+ int ret;
+ V9fsString fullname;
+ v9fs_string_init(&fullname);
+
+ v9fs_string_sprintf(&fullname, "%s/%s", dir->data, name);
+ ret = proxy_remove(ctx, fullname.data);
+ v9fs_string_free(&fullname);
+
+ return ret;
+}
+
+static int proxy_ioc_getversion(FsContext *fs_ctx, V9fsPath *path,
+ mode_t st_mode, uint64_t *st_gen)
+{
+ int err;
+
+ /* Do not try to open special files like device nodes, fifos etc
+ * we can get fd for regular files and directories only
+ */
+ if (!S_ISREG(st_mode) && !S_ISDIR(st_mode)) {
+ errno = ENOTTY;
+ return -1;
+ }
+ err = v9fs_request(fs_ctx->private, T_GETVERSION, st_gen, "s", path);
+ if (err < 0) {
+ errno = -err;
+ err = -1;
+ }
+ return err;
+}
+
+static int connect_namedsocket(const char *path)
+{
+ int sockfd, size;
+ struct sockaddr_un helper;
+
+ if (strlen(path) >= sizeof(helper.sun_path)) {
+ error_report("Socket name too long");
+ return -1;
+ }
+ sockfd = socket(AF_UNIX, SOCK_STREAM, 0);
+ if (sockfd < 0) {
+ error_report("Failed to create socket: %s", strerror(errno));
+ return -1;
+ }
+ 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) {
+ error_report("Failed to connect to %s: %s", path, strerror(errno));
+ close(sockfd);
+ 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) {
+ error_report("Must specify either socket or sock_fd");
+ return -1;
+ }
+ if (socket && sock_fd) {
+ error_report("Both socket and sock_fd options specified");
+ 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;
+}
+
+static int proxy_init(FsContext *ctx)
+{
+ V9fsProxy *proxy = g_malloc(sizeof(V9fsProxy));
+ int sock_id;
+
+ 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) {
+ error_report("Socket descriptor not initialized");
+ }
+ }
+ if (sock_id < 0) {
+ g_free(proxy);
+ return -1;
+ }
+ g_free(ctx->fs_root);
+ ctx->fs_root = NULL;
+
+ proxy->in_iovec.iov_base = g_malloc(PROXY_MAX_IO_SZ + PROXY_HDR_SZ);
+ proxy->in_iovec.iov_len = PROXY_MAX_IO_SZ + PROXY_HDR_SZ;
+ proxy->out_iovec.iov_base = g_malloc(PROXY_MAX_IO_SZ + PROXY_HDR_SZ);
+ proxy->out_iovec.iov_len = PROXY_MAX_IO_SZ + PROXY_HDR_SZ;
+
+ ctx->private = proxy;
+ proxy->sockfd = sock_id;
+ qemu_mutex_init(&proxy->mutex);
+
+ ctx->export_flags |= V9FS_PATHNAME_FSCONTEXT;
+ ctx->exops.get_st_gen = proxy_ioc_getversion;
+ return 0;
+}
+
+FileOperations proxy_ops = {
+ .parse_opts = proxy_parse_opts,
+ .init = proxy_init,
+ .lstat = proxy_lstat,
+ .readlink = proxy_readlink,
+ .close = proxy_close,
+ .closedir = proxy_closedir,
+ .open = proxy_open,
+ .opendir = proxy_opendir,
+ .rewinddir = proxy_rewinddir,
+ .telldir = proxy_telldir,
+ .readdir_r = proxy_readdir_r,
+ .seekdir = proxy_seekdir,
+ .preadv = proxy_preadv,
+ .pwritev = proxy_pwritev,
+ .chmod = proxy_chmod,
+ .mknod = proxy_mknod,
+ .mkdir = proxy_mkdir,
+ .fstat = proxy_fstat,
+ .open2 = proxy_open2,
+ .symlink = proxy_symlink,
+ .link = proxy_link,
+ .truncate = proxy_truncate,
+ .rename = proxy_rename,
+ .chown = proxy_chown,
+ .utimensat = proxy_utimensat,
+ .remove = proxy_remove,
+ .fsync = proxy_fsync,
+ .statfs = proxy_statfs,
+ .lgetxattr = proxy_lgetxattr,
+ .llistxattr = proxy_llistxattr,
+ .lsetxattr = proxy_lsetxattr,
+ .lremovexattr = proxy_lremovexattr,
+ .name_to_path = proxy_name_to_path,
+ .renameat = proxy_renameat,
+ .unlinkat = proxy_unlinkat,
+};