--- /dev/null
+/*
+ * Helper for QEMU Proxy FS Driver
+ * 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 <sys/resource.h>
+#include <getopt.h>
+#include <syslog.h>
+#include <sys/capability.h>
+#include <sys/fsuid.h>
+#include <sys/vfs.h>
+#include <sys/ioctl.h>
+#include <linux/fs.h>
+#ifdef CONFIG_LINUX_MAGIC_H
+#include <linux/magic.h>
+#endif
+#include "qemu-common.h"
+#include "qemu/sockets.h"
+#include "qemu/xattr.h"
+#include "virtio-9p-marshal.h"
+#include "hw/9pfs/virtio-9p-proxy.h"
+#include "fsdev/virtio-9p-marshal.h"
+
+#define PROGNAME "virtfs-proxy-helper"
+
+#ifndef XFS_SUPER_MAGIC
+#define XFS_SUPER_MAGIC 0x58465342
+#endif
+#ifndef EXT2_SUPER_MAGIC
+#define EXT2_SUPER_MAGIC 0xEF53
+#endif
+#ifndef REISERFS_SUPER_MAGIC
+#define REISERFS_SUPER_MAGIC 0x52654973
+#endif
+#ifndef BTRFS_SUPER_MAGIC
+#define BTRFS_SUPER_MAGIC 0x9123683E
+#endif
+
+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;
+static bool get_version; /* IOC getversion IOCTL supported */
+
+static void GCC_FMT_ATTR(2, 3) do_log(int loglevel, const char *format, ...)
+{
+ va_list ap;
+
+ va_start(ap, format);
+ if (is_daemon) {
+ vsyslog(LOG_CRIT, format, ap);
+ } else {
+ vfprintf(stderr, format, ap);
+ }
+ va_end(ap);
+}
+
+static void do_perror(const char *string)
+{
+ if (is_daemon) {
+ syslog(LOG_CRIT, "%s:%s", string, strerror(errno));
+ } else {
+ fprintf(stderr, "%s:%s\n", string, strerror(errno));
+ }
+}
+
+static int do_cap_set(cap_value_t *cap_value, int size, int reset)
+{
+ cap_t caps;
+ if (reset) {
+ /*
+ * Start with an empty set and set permitted and effective
+ */
+ caps = cap_init();
+ if (caps == NULL) {
+ do_perror("cap_init");
+ return -1;
+ }
+ if (cap_set_flag(caps, CAP_PERMITTED, size, cap_value, CAP_SET) < 0) {
+ do_perror("cap_set_flag");
+ goto error;
+ }
+ } else {
+ caps = cap_get_proc();
+ if (!caps) {
+ do_perror("cap_get_proc");
+ return -1;
+ }
+ }
+ if (cap_set_flag(caps, CAP_EFFECTIVE, size, cap_value, CAP_SET) < 0) {
+ do_perror("cap_set_flag");
+ goto error;
+ }
+ if (cap_set_proc(caps) < 0) {
+ do_perror("cap_set_proc");
+ goto error;
+ }
+ cap_free(caps);
+ return 0;
+
+error:
+ cap_free(caps);
+ return -1;
+}
+
+static int init_capabilities(void)
+{
+ /* helper needs following capabilities only */
+ cap_value_t cap_list[] = {
+ CAP_CHOWN,
+ CAP_DAC_OVERRIDE,
+ CAP_FOWNER,
+ CAP_FSETID,
+ CAP_SETGID,
+ CAP_MKNOD,
+ CAP_SETUID,
+ };
+ return do_cap_set(cap_list, ARRAY_SIZE(cap_list), 1);
+}
+
+static int socket_read(int sockfd, void *buff, ssize_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;
+}
+
+static int socket_write(int sockfd, void *buff, ssize_t size)
+{
+ ssize_t retval, total = 0;
+
+ while (size) {
+ retval = write(sockfd, buff, size);
+ if (retval < 0) {
+ if (errno == EINTR) {
+ continue;
+ }
+ return -errno;
+ }
+ size -= retval;
+ buff += retval;
+ total += retval;
+ }
+ return total;
+}
+
+static int read_request(int sockfd, struct iovec *iovec, ProxyHeader *header)
+{
+ int retval;
+
+ /*
+ * read the request header.
+ */
+ iovec->iov_len = 0;
+ retval = socket_read(sockfd, iovec->iov_base, PROXY_HDR_SZ);
+ if (retval < 0) {
+ return retval;
+ }
+ iovec->iov_len = PROXY_HDR_SZ;
+ retval = proxy_unmarshal(iovec, 0, "dd", &header->type, &header->size);
+ if (retval < 0) {
+ return retval;
+ }
+ /*
+ * We can't process message.size > PROXY_MAX_IO_SZ.
+ * Treat it as fatal error
+ */
+ if (header->size > PROXY_MAX_IO_SZ) {
+ return -ENOBUFS;
+ }
+ retval = socket_read(sockfd, iovec->iov_base + PROXY_HDR_SZ, header->size);
+ if (retval < 0) {
+ return retval;
+ }
+ iovec->iov_len += header->size;
+ return 0;
+}
+
+static int send_fd(int sockfd, int fd)
+{
+ struct msghdr msg;
+ struct iovec iov;
+ int retval, data;
+ struct cmsghdr *cmsg;
+ 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;
+ /* No ancillary data on error */
+ if (fd < 0) {
+ /* fd is really negative errno if the request failed */
+ data = fd;
+ } else {
+ data = V9FS_FD_VALID;
+ msg.msg_control = &msg_control;
+ msg.msg_controllen = sizeof(msg_control);
+
+ cmsg = &msg_control.cmsg;
+ cmsg->cmsg_len = CMSG_LEN(sizeof(fd));
+ cmsg->cmsg_level = SOL_SOCKET;
+ cmsg->cmsg_type = SCM_RIGHTS;
+ memcpy(CMSG_DATA(cmsg), &fd, sizeof(fd));
+ }
+
+ do {
+ retval = sendmsg(sockfd, &msg, 0);
+ } while (retval < 0 && errno == EINTR);
+ if (fd >= 0) {
+ close(fd);
+ }
+ if (retval < 0) {
+ return retval;
+ }
+ return 0;
+}
+
+static int send_status(int sockfd, struct iovec *iovec, int status)
+{
+ ProxyHeader header;
+ int retval, msg_size;
+
+ if (status < 0) {
+ header.type = T_ERROR;
+ } else {
+ header.type = T_SUCCESS;
+ }
+ header.size = sizeof(status);
+ /*
+ * marshal the return status. We don't check error.
+ * because we are sure we have enough space for the status
+ */
+ msg_size = proxy_marshal(iovec, 0, "ddd", header.type,
+ header.size, status);
+ if (msg_size < 0) {
+ return msg_size;
+ }
+ retval = socket_write(sockfd, iovec->iov_base, msg_size);
+ if (retval < 0) {
+ return retval;
+ }
+ return 0;
+}
+
+/*
+ * from man 7 capabilities, section
+ * Effect of User ID Changes on Capabilities:
+ * If the effective user ID is changed from nonzero to 0, then the permitted
+ * set is copied to the effective set. If the effective user ID is changed
+ * from 0 to nonzero, then all capabilities are are cleared from the effective
+ * set.
+ *
+ * The setfsuid/setfsgid man pages warn that changing the effective user ID may
+ * expose the program to unwanted signals, but this is not true anymore: for an
+ * unprivileged (without CAP_KILL) program to send a signal, the real or
+ * effective user ID of the sending process must equal the real or saved user
+ * ID of the target process. Even when dropping privileges, it is enough to
+ * keep the saved UID to a "privileged" value and virtfs-proxy-helper won't
+ * be exposed to signals. So just use setresuid/setresgid.
+ */
+static int setugid(int uid, int gid, int *suid, int *sgid)
+{
+ int retval;
+
+ /*
+ * We still need DAC_OVERRIDE because we don't change
+ * supplementary group ids, and hence may be subjected DAC rules
+ */
+ cap_value_t cap_list[] = {
+ CAP_DAC_OVERRIDE,
+ };
+
+ *suid = geteuid();
+ *sgid = getegid();
+
+ if (setresgid(-1, gid, *sgid) == -1) {
+ retval = -errno;
+ goto err_out;
+ }
+
+ if (setresuid(-1, uid, *suid) == -1) {
+ retval = -errno;
+ goto err_sgid;
+ }
+
+ if (uid != 0 || gid != 0) {
+ if (do_cap_set(cap_list, ARRAY_SIZE(cap_list), 0) < 0) {
+ retval = -errno;
+ goto err_suid;
+ }
+ }
+ return 0;
+
+err_suid:
+ if (setresuid(-1, *suid, *suid) == -1) {
+ abort();
+ }
+err_sgid:
+ if (setresgid(-1, *sgid, *sgid) == -1) {
+ abort();
+ }
+err_out:
+ return retval;
+}
+
+/*
+ * This is used to reset the ugid back with the saved values
+ * There is nothing much we can do checking error values here.
+ */
+static void resetugid(int suid, int sgid)
+{
+ if (setresgid(-1, sgid, sgid) == -1) {
+ abort();
+ }
+ if (setresuid(-1, suid, suid) == -1) {
+ abort();
+ }
+}
+
+/*
+ * send response in two parts
+ * 1) ProxyHeader
+ * 2) Response or error status
+ * This function should be called with marshaled response
+ * send_response constructs header part and error part only.
+ * send response sends {ProxyHeader,Response} if the request was success
+ * otherwise sends {ProxyHeader,error status}
+ */
+static int send_response(int sock, struct iovec *iovec, int size)
+{
+ int retval;
+ ProxyHeader header;
+
+ /*
+ * If response size exceeds available iovec->iov_len,
+ * we return ENOBUFS
+ */
+ if (size > PROXY_MAX_IO_SZ) {
+ size = -ENOBUFS;
+ }
+
+ if (size < 0) {
+ /*
+ * In case of error we would not have got the error encoded
+ * already so encode the error here.
+ */
+ header.type = T_ERROR;
+ header.size = sizeof(size);
+ proxy_marshal(iovec, PROXY_HDR_SZ, "d", size);
+ } else {
+ header.type = T_SUCCESS;
+ header.size = size;
+ }
+ proxy_marshal(iovec, 0, "dd", header.type, header.size);
+ retval = socket_write(sock, iovec->iov_base, header.size + PROXY_HDR_SZ);
+ if (retval < 0) {
+ return retval;
+ }
+ return 0;
+}
+
+/*
+ * gets generation number
+ * returns -errno on failure and sizeof(generation number) on success
+ */
+static int do_getversion(struct iovec *iovec, struct iovec *out_iovec)
+{
+ uint64_t version;
+ int retval = -ENOTTY;
+#ifdef FS_IOC_GETVERSION
+ int fd;
+ V9fsString path;
+#endif
+
+
+ /* no need to issue ioctl */
+ if (!get_version) {
+ version = 0;
+ retval = proxy_marshal(out_iovec, PROXY_HDR_SZ, "q", version);
+ return retval;
+ }
+#ifdef FS_IOC_GETVERSION
+ retval = proxy_unmarshal(iovec, PROXY_HDR_SZ, "s", &path);
+ if (retval < 0) {
+ return retval;
+ }
+
+ fd = open(path.data, O_RDONLY);
+ if (fd < 0) {
+ retval = -errno;
+ goto err_out;
+ }
+ if (ioctl(fd, FS_IOC_GETVERSION, &version) < 0) {
+ retval = -errno;
+ } else {
+ retval = proxy_marshal(out_iovec, PROXY_HDR_SZ, "q", version);
+ }
+ close(fd);
+err_out:
+ v9fs_string_free(&path);
+#endif
+ return retval;
+}
+
+static int do_getxattr(int type, struct iovec *iovec, struct iovec *out_iovec)
+{
+ int size = 0, offset, retval;
+ V9fsString path, name, xattr;
+
+ v9fs_string_init(&xattr);
+ v9fs_string_init(&path);
+ retval = proxy_unmarshal(iovec, PROXY_HDR_SZ, "ds", &size, &path);
+ if (retval < 0) {
+ return retval;
+ }
+ offset = PROXY_HDR_SZ + retval;
+
+ if (size) {
+ xattr.data = g_malloc(size);
+ xattr.size = size;
+ }
+ switch (type) {
+ case T_LGETXATTR:
+ v9fs_string_init(&name);
+ retval = proxy_unmarshal(iovec, offset, "s", &name);
+ if (retval > 0) {
+ retval = lgetxattr(path.data, name.data, xattr.data, size);
+ if (retval < 0) {
+ retval = -errno;
+ } else {
+ xattr.size = retval;
+ }
+ }
+ v9fs_string_free(&name);
+ break;
+ case T_LLISTXATTR:
+ retval = llistxattr(path.data, xattr.data, size);
+ if (retval < 0) {
+ retval = -errno;
+ } else {
+ xattr.size = retval;
+ }
+ break;
+ }
+ if (retval < 0) {
+ goto err_out;
+ }
+
+ if (!size) {
+ proxy_marshal(out_iovec, PROXY_HDR_SZ, "d", retval);
+ retval = sizeof(retval);
+ } else {
+ retval = proxy_marshal(out_iovec, PROXY_HDR_SZ, "s", &xattr);
+ }
+err_out:
+ v9fs_string_free(&xattr);
+ v9fs_string_free(&path);
+ return retval;
+}
+
+static void stat_to_prstat(ProxyStat *pr_stat, struct stat *stat)
+{
+ memset(pr_stat, 0, sizeof(*pr_stat));
+ pr_stat->st_dev = stat->st_dev;
+ pr_stat->st_ino = stat->st_ino;
+ pr_stat->st_nlink = stat->st_nlink;
+ pr_stat->st_mode = stat->st_mode;
+ pr_stat->st_uid = stat->st_uid;
+ pr_stat->st_gid = stat->st_gid;
+ pr_stat->st_rdev = stat->st_rdev;
+ pr_stat->st_size = stat->st_size;
+ pr_stat->st_blksize = stat->st_blksize;
+ pr_stat->st_blocks = stat->st_blocks;
+ pr_stat->st_atim_sec = stat->st_atim.tv_sec;
+ pr_stat->st_atim_nsec = stat->st_atim.tv_nsec;
+ pr_stat->st_mtim_sec = stat->st_mtim.tv_sec;
+ pr_stat->st_mtim_nsec = stat->st_mtim.tv_nsec;
+ pr_stat->st_ctim_sec = stat->st_ctim.tv_sec;
+ pr_stat->st_ctim_nsec = stat->st_ctim.tv_nsec;
+}
+
+static void statfs_to_prstatfs(ProxyStatFS *pr_stfs, struct statfs *stfs)
+{
+ memset(pr_stfs, 0, sizeof(*pr_stfs));
+ pr_stfs->f_type = stfs->f_type;
+ pr_stfs->f_bsize = stfs->f_bsize;
+ pr_stfs->f_blocks = stfs->f_blocks;
+ pr_stfs->f_bfree = stfs->f_bfree;
+ pr_stfs->f_bavail = stfs->f_bavail;
+ pr_stfs->f_files = stfs->f_files;
+ pr_stfs->f_ffree = stfs->f_ffree;
+ pr_stfs->f_fsid[0] = stfs->f_fsid.__val[0];
+ pr_stfs->f_fsid[1] = stfs->f_fsid.__val[1];
+ pr_stfs->f_namelen = stfs->f_namelen;
+ pr_stfs->f_frsize = stfs->f_frsize;
+}
+
+/*
+ * Gets stat/statfs information and packs in out_iovec structure
+ * on success returns number of bytes packed in out_iovec struture
+ * otherwise returns -errno
+ */
+static int do_stat(int type, struct iovec *iovec, struct iovec *out_iovec)
+{
+ int retval;
+ V9fsString path;
+ ProxyStat pr_stat;
+ ProxyStatFS pr_stfs;
+ struct stat st_buf;
+ struct statfs stfs_buf;
+
+ v9fs_string_init(&path);
+ retval = proxy_unmarshal(iovec, PROXY_HDR_SZ, "s", &path);
+ if (retval < 0) {
+ return retval;
+ }
+
+ switch (type) {
+ case T_LSTAT:
+ retval = lstat(path.data, &st_buf);
+ if (retval < 0) {
+ retval = -errno;
+ } else {
+ stat_to_prstat(&pr_stat, &st_buf);
+ retval = proxy_marshal(out_iovec, PROXY_HDR_SZ,
+ "qqqdddqqqqqqqqqq", pr_stat.st_dev,
+ pr_stat.st_ino, pr_stat.st_nlink,
+ pr_stat.st_mode, pr_stat.st_uid,
+ pr_stat.st_gid, pr_stat.st_rdev,
+ pr_stat.st_size, pr_stat.st_blksize,
+ pr_stat.st_blocks,
+ pr_stat.st_atim_sec, pr_stat.st_atim_nsec,
+ pr_stat.st_mtim_sec, pr_stat.st_mtim_nsec,
+ pr_stat.st_ctim_sec, pr_stat.st_ctim_nsec);
+ }
+ break;
+ case T_STATFS:
+ retval = statfs(path.data, &stfs_buf);
+ if (retval < 0) {
+ retval = -errno;
+ } else {
+ statfs_to_prstatfs(&pr_stfs, &stfs_buf);
+ retval = proxy_marshal(out_iovec, PROXY_HDR_SZ,
+ "qqqqqqqqqqq", pr_stfs.f_type,
+ pr_stfs.f_bsize, pr_stfs.f_blocks,
+ pr_stfs.f_bfree, pr_stfs.f_bavail,
+ pr_stfs.f_files, pr_stfs.f_ffree,
+ pr_stfs.f_fsid[0], pr_stfs.f_fsid[1],
+ pr_stfs.f_namelen, pr_stfs.f_frsize);
+ }
+ break;
+ }
+ v9fs_string_free(&path);
+ return retval;
+}
+
+static int do_readlink(struct iovec *iovec, struct iovec *out_iovec)
+{
+ char *buffer;
+ int size, retval;
+ V9fsString target, path;
+
+ v9fs_string_init(&path);
+ retval = proxy_unmarshal(iovec, PROXY_HDR_SZ, "sd", &path, &size);
+ if (retval < 0) {
+ v9fs_string_free(&path);
+ return retval;
+ }
+ buffer = g_malloc(size);
+ v9fs_string_init(&target);
+ retval = readlink(path.data, buffer, size - 1);
+ if (retval > 0) {
+ buffer[retval] = '\0';
+ v9fs_string_sprintf(&target, "%s", buffer);
+ retval = proxy_marshal(out_iovec, PROXY_HDR_SZ, "s", &target);
+ } else {
+ retval = -errno;
+ }
+ g_free(buffer);
+ v9fs_string_free(&target);
+ v9fs_string_free(&path);
+ return retval;
+}
+
+/*
+ * create other filesystem objects and send 0 on success
+ * return -errno on error
+ */
+static int do_create_others(int type, struct iovec *iovec)
+{
+ dev_t rdev;
+ int retval = 0;
+ int offset = PROXY_HDR_SZ;
+ V9fsString oldpath, path;
+ int mode, uid, gid, cur_uid, cur_gid;
+
+ v9fs_string_init(&path);
+ v9fs_string_init(&oldpath);
+
+ retval = proxy_unmarshal(iovec, offset, "dd", &uid, &gid);
+ if (retval < 0) {
+ return retval;
+ }
+ offset += retval;
+ retval = setugid(uid, gid, &cur_uid, &cur_gid);
+ if (retval < 0) {
+ goto unmarshal_err_out;
+ }
+ switch (type) {
+ case T_MKNOD:
+ retval = proxy_unmarshal(iovec, offset, "sdq", &path, &mode, &rdev);
+ if (retval < 0) {
+ goto err_out;
+ }
+ retval = mknod(path.data, mode, rdev);
+ break;
+ case T_MKDIR:
+ retval = proxy_unmarshal(iovec, offset, "sd", &path, &mode);
+ if (retval < 0) {
+ goto err_out;
+ }
+ retval = mkdir(path.data, mode);
+ break;
+ case T_SYMLINK:
+ retval = proxy_unmarshal(iovec, offset, "ss", &oldpath, &path);
+ if (retval < 0) {
+ goto err_out;
+ }
+ retval = symlink(oldpath.data, path.data);
+ break;
+ }
+ if (retval < 0) {
+ retval = -errno;
+ }
+
+err_out:
+ resetugid(cur_uid, cur_gid);
+unmarshal_err_out:
+ v9fs_string_free(&path);
+ v9fs_string_free(&oldpath);
+ return retval;
+}
+
+/*
+ * create a file and send fd on success
+ * return -errno on error
+ */
+static int do_create(struct iovec *iovec)
+{
+ int ret;
+ V9fsString path;
+ int flags, mode, uid, gid, cur_uid, cur_gid;
+
+ v9fs_string_init(&path);
+ ret = proxy_unmarshal(iovec, PROXY_HDR_SZ, "sdddd",
+ &path, &flags, &mode, &uid, &gid);
+ if (ret < 0) {
+ goto unmarshal_err_out;
+ }
+ ret = setugid(uid, gid, &cur_uid, &cur_gid);
+ if (ret < 0) {
+ goto unmarshal_err_out;
+ }
+ ret = open(path.data, flags, mode);
+ if (ret < 0) {
+ ret = -errno;
+ }
+
+ resetugid(cur_uid, cur_gid);
+unmarshal_err_out:
+ v9fs_string_free(&path);
+ return ret;
+}
+
+/*
+ * open a file and send fd on success
+ * return -errno on error
+ */
+static int do_open(struct iovec *iovec)
+{
+ int flags, ret;
+ V9fsString path;
+
+ v9fs_string_init(&path);
+ ret = proxy_unmarshal(iovec, PROXY_HDR_SZ, "sd", &path, &flags);
+ if (ret < 0) {
+ goto err_out;
+ }
+ ret = open(path.data, flags);
+ if (ret < 0) {
+ ret = -errno;
+ }
+err_out:
+ v9fs_string_free(&path);
+ 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;
+ }
+
+ if (strlen(path) >= sizeof(proxy.sun_path)) {
+ do_log(LOG_CRIT, "UNIX domain socket path exceeds %zu characters\n",
+ sizeof(proxy.sun_path));
+ 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");
+ goto error;
+ }
+ if (chown(proxy.sun_path, uid, gid) < 0) {
+ do_perror("chown");
+ goto error;
+ }
+ if (listen(sock, 1) < 0) {
+ do_perror("listen");
+ goto error;
+ }
+
+ size = sizeof(qemu);
+ client = accept(sock, (struct sockaddr *)&qemu, &size);
+ if (client < 0) {
+ do_perror("accept");
+ goto error;
+ }
+ close(sock);
+ return client;
+
+error:
+ close(sock);
+ return -1;
+}
+
+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));
+}
+
+static int process_reply(int sock, int type,
+ struct iovec *out_iovec, int retval)
+{
+ switch (type) {
+ case T_OPEN:
+ case T_CREATE:
+ if (send_fd(sock, retval) < 0) {
+ return -1;
+ }
+ break;
+ case T_MKNOD:
+ case T_MKDIR:
+ case T_SYMLINK:
+ case T_LINK:
+ case T_CHMOD:
+ case T_CHOWN:
+ case T_TRUNCATE:
+ case T_UTIME:
+ case T_RENAME:
+ case T_REMOVE:
+ case T_LSETXATTR:
+ case T_LREMOVEXATTR:
+ if (send_status(sock, out_iovec, retval) < 0) {
+ return -1;
+ }
+ break;
+ case T_LSTAT:
+ case T_STATFS:
+ case T_READLINK:
+ case T_LGETXATTR:
+ case T_LLISTXATTR:
+ case T_GETVERSION:
+ if (send_response(sock, out_iovec, retval) < 0) {
+ return -1;
+ }
+ break;
+ default:
+ return -1;
+ break;
+ }
+ return 0;
+}
+
+static int process_requests(int sock)
+{
+ int flags;
+ int size = 0;
+ int retval = 0;
+ uint64_t offset;
+ ProxyHeader header;
+ int mode, uid, gid;
+ V9fsString name, value;
+ struct timespec spec[2];
+ V9fsString oldpath, path;
+ struct iovec in_iovec, out_iovec;
+
+ in_iovec.iov_base = g_malloc(PROXY_MAX_IO_SZ + PROXY_HDR_SZ);
+ in_iovec.iov_len = PROXY_MAX_IO_SZ + PROXY_HDR_SZ;
+ out_iovec.iov_base = g_malloc(PROXY_MAX_IO_SZ + PROXY_HDR_SZ);
+ out_iovec.iov_len = PROXY_MAX_IO_SZ + PROXY_HDR_SZ;
+
+ while (1) {
+ /*
+ * initialize the header type, so that we send
+ * response to proper request type.
+ */
+ header.type = 0;
+ retval = read_request(sock, &in_iovec, &header);
+ if (retval < 0) {
+ goto err_out;
+ }
+
+ switch (header.type) {
+ case T_OPEN:
+ retval = do_open(&in_iovec);
+ break;
+ case T_CREATE:
+ retval = do_create(&in_iovec);
+ break;
+ case T_MKNOD:
+ case T_MKDIR:
+ case T_SYMLINK:
+ retval = do_create_others(header.type, &in_iovec);
+ break;
+ case T_LINK:
+ v9fs_string_init(&path);
+ v9fs_string_init(&oldpath);
+ retval = proxy_unmarshal(&in_iovec, PROXY_HDR_SZ,
+ "ss", &oldpath, &path);
+ if (retval > 0) {
+ retval = link(oldpath.data, path.data);
+ if (retval < 0) {
+ retval = -errno;
+ }
+ }
+ v9fs_string_free(&oldpath);
+ v9fs_string_free(&path);
+ break;
+ case T_LSTAT:
+ case T_STATFS:
+ retval = do_stat(header.type, &in_iovec, &out_iovec);
+ break;
+ case T_READLINK:
+ retval = do_readlink(&in_iovec, &out_iovec);
+ break;
+ case T_CHMOD:
+ v9fs_string_init(&path);
+ retval = proxy_unmarshal(&in_iovec, PROXY_HDR_SZ,
+ "sd", &path, &mode);
+ if (retval > 0) {
+ retval = chmod(path.data, mode);
+ if (retval < 0) {
+ retval = -errno;
+ }
+ }
+ v9fs_string_free(&path);
+ break;
+ case T_CHOWN:
+ v9fs_string_init(&path);
+ retval = proxy_unmarshal(&in_iovec, PROXY_HDR_SZ, "sdd", &path,
+ &uid, &gid);
+ if (retval > 0) {
+ retval = lchown(path.data, uid, gid);
+ if (retval < 0) {
+ retval = -errno;
+ }
+ }
+ v9fs_string_free(&path);
+ break;
+ case T_TRUNCATE:
+ v9fs_string_init(&path);
+ retval = proxy_unmarshal(&in_iovec, PROXY_HDR_SZ, "sq",
+ &path, &offset);
+ if (retval > 0) {
+ retval = truncate(path.data, offset);
+ if (retval < 0) {
+ retval = -errno;
+ }
+ }
+ v9fs_string_free(&path);
+ break;
+ case T_UTIME:
+ v9fs_string_init(&path);
+ retval = proxy_unmarshal(&in_iovec, PROXY_HDR_SZ, "sqqqq", &path,
+ &spec[0].tv_sec, &spec[0].tv_nsec,
+ &spec[1].tv_sec, &spec[1].tv_nsec);
+ if (retval > 0) {
+ retval = qemu_utimens(path.data, spec);
+ if (retval < 0) {
+ retval = -errno;
+ }
+ }
+ v9fs_string_free(&path);
+ break;
+ case T_RENAME:
+ v9fs_string_init(&path);
+ v9fs_string_init(&oldpath);
+ retval = proxy_unmarshal(&in_iovec, PROXY_HDR_SZ,
+ "ss", &oldpath, &path);
+ if (retval > 0) {
+ retval = rename(oldpath.data, path.data);
+ if (retval < 0) {
+ retval = -errno;
+ }
+ }
+ v9fs_string_free(&oldpath);
+ v9fs_string_free(&path);
+ break;
+ case T_REMOVE:
+ v9fs_string_init(&path);
+ retval = proxy_unmarshal(&in_iovec, PROXY_HDR_SZ, "s", &path);
+ if (retval > 0) {
+ retval = remove(path.data);
+ if (retval < 0) {
+ retval = -errno;
+ }
+ }
+ v9fs_string_free(&path);
+ break;
+ case T_LGETXATTR:
+ case T_LLISTXATTR:
+ retval = do_getxattr(header.type, &in_iovec, &out_iovec);
+ break;
+ case T_LSETXATTR:
+ v9fs_string_init(&path);
+ v9fs_string_init(&name);
+ v9fs_string_init(&value);
+ retval = proxy_unmarshal(&in_iovec, PROXY_HDR_SZ, "sssdd", &path,
+ &name, &value, &size, &flags);
+ if (retval > 0) {
+ retval = lsetxattr(path.data,
+ name.data, value.data, size, flags);
+ if (retval < 0) {
+ retval = -errno;
+ }
+ }
+ v9fs_string_free(&path);
+ v9fs_string_free(&name);
+ v9fs_string_free(&value);
+ break;
+ case T_LREMOVEXATTR:
+ v9fs_string_init(&path);
+ v9fs_string_init(&name);
+ retval = proxy_unmarshal(&in_iovec,
+ PROXY_HDR_SZ, "ss", &path, &name);
+ if (retval > 0) {
+ retval = lremovexattr(path.data, name.data);
+ if (retval < 0) {
+ retval = -errno;
+ }
+ }
+ v9fs_string_free(&path);
+ v9fs_string_free(&name);
+ break;
+ case T_GETVERSION:
+ retval = do_getversion(&in_iovec, &out_iovec);
+ break;
+ default:
+ goto err_out;
+ break;
+ }
+
+ if (process_reply(sock, header.type, &out_iovec, retval) < 0) {
+ goto err_out;
+ }
+ }
+err_out:
+ g_free(in_iovec.iov_base);
+ g_free(out_iovec.iov_base);
+ return -1;
+}
+
+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
+ int retval;
+ struct statfs st_fs;
+#endif
+
+ is_daemon = true;
+ sock = -1;
+ own_u = own_g = -1;
+ while (1) {
+ option_index = 0;
+ c = getopt_long(argc, argv, "p:nh?f:s:u:g:", helper_opts,
+ &option_index);
+ if (c == -1) {
+ break;
+ }
+ switch (c) {
+ case 'p':
+ rpath = g_strdup(optarg);
+ break;
+ case 'n':
+ is_daemon = false;
+ break;
+ case 'f':
+ sock = atoi(optarg);
+ break;
+ case 's':
+ sock_name = g_strdup(optarg);
+ break;
+ case 'u':
+ own_u = atoi(optarg);
+ break;
+ case 'g':
+ own_g = atoi(optarg);
+ break;
+ case '?':
+ case 'h':
+ default:
+ usage(argv[0]);
+ exit(EXIT_FAILURE);
+ }
+ }
+
+ /* Parameter validation */
+ 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 && sock != -1) {
+ fprintf(stderr, "both named socket and socket descriptor specified\n");
+ usage(argv[0]);
+ exit(EXIT_FAILURE);
+ }
+
+ 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);
+ }
+
+ if (lstat(rpath, &stbuf) < 0) {
+ fprintf(stderr, "invalid path \"%s\" specified, %s\n",
+ rpath, strerror(errno));
+ exit(EXIT_FAILURE);
+ }
+
+ if (!S_ISDIR(stbuf.st_mode)) {
+ fprintf(stderr, "specified path \"%s\" is not directory\n", rpath);
+ exit(EXIT_FAILURE);
+ }
+
+ if (is_daemon) {
+ if (daemon(0, 0) < 0) {
+ fprintf(stderr, "daemon call failed\n");
+ exit(EXIT_FAILURE);
+ }
+ openlog(PROGNAME, LOG_PID, LOG_DAEMON);
+ }
+
+ 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
+ /* check whether underlying FS support IOC_GETVERSION */
+ retval = statfs(rpath, &st_fs);
+ if (!retval) {
+ switch (st_fs.f_type) {
+ case EXT2_SUPER_MAGIC:
+ case BTRFS_SUPER_MAGIC:
+ case REISERFS_SUPER_MAGIC:
+ case XFS_SUPER_MAGIC:
+ get_version = true;
+ break;
+ }
+ }
+#endif
+
+ if (chdir("/") < 0) {
+ do_perror("chdir");
+ goto error;
+ }
+ if (chroot(rpath) < 0) {
+ do_perror("chroot");
+ goto error;
+ }
+ umask(0);
+
+ if (init_capabilities() < 0) {
+ goto error;
+ }
+
+ process_requests(sock);
+error:
+ do_log(LOG_INFO, "Done\n");
+ closelog();
+ return 0;
+}
Code Review / kvmfornfv.git / blobdiff