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qemu-e2k/fsdev/virtfs-proxy-helper.c
Paolo Bonzini 7e46261368 virtfs-proxy-helper: switch from libcap to libcap-ng 
virtfs-proxy-helper is the only user of libcap; everyone else is using
the simpler libcap-ng API.  Switch and remove the configure code to
detect libcap.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
[groug: - drop remaining -lcap from Makefile
        - fix error message in configure]
Signed-off-by: Greg Kurz <groug@kaod.org>
2019-12-02 15:26:33 +01:00

1164 lines
31 KiB
C
Raw Blame History

/*
* 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 "qemu/osdep.h"
#include <sys/resource.h>
#include <getopt.h>
#include <syslog.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 <cap-ng.h>
#include "qemu-common.h"
#include "qemu/sockets.h"
#include "qemu/xattr.h"
#include "9p-iov-marshal.h"
#include "hw/9pfs/9p-proxy.h"
#include "fsdev/9p-iov-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 char *prog_name;
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 init_capabilities(void)
{
/* helper needs following capabilities only */
int cap_list[] = {
CAP_CHOWN,
CAP_DAC_OVERRIDE,
CAP_FOWNER,
CAP_FSETID,
CAP_SETGID,
CAP_MKNOD,
CAP_SETUID,
};
int i;
capng_clear(CAPNG_SELECT_BOTH);
for (i = 0; i < ARRAY_SIZE(cap_list); i++) {
if (capng_update(CAPNG_ADD, CAPNG_EFFECTIVE | CAPNG_PERMITTED,
cap_list[i]) < 0) {
do_perror("capng_update");
return -1;
}
}
if (capng_apply(CAPNG_SELECT_BOTH) < 0) {
do_perror("capng_apply");
return -1;
}
/* Prepare effective set for setugid. */
for (i = 0; i < ARRAY_SIZE(cap_list); i++) {
if (cap_list[i] == CAP_DAC_OVERRIDE) {
continue;
}
if (capng_update(CAPNG_DROP, CAPNG_EFFECTIVE,
cap_list[i]) < 0) {
do_perror("capng_update");
return -1;
}
}
return 0;
}
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;
*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) {
/* Linux has already copied the permitted set to the effective set. */
return 0;
}
/*
* All capabilities have been cleared from the effective set. However
* we still need DAC_OVERRIDE because we don't change supplementary
* group ids, and hence may be subject to DAC rules. init_capabilities
* left the set of capabilities that we want in libcap-ng's state.
*/
if (capng_apply(CAPNG_SELECT_CAPS) < 0) {
retval = -errno;
do_perror("capng_apply");
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(void)
{
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",
prog_name);
}
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 = utimensat(AT_FDCWD, path.data, spec,
AT_SYMLINK_NOFOLLOW);
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
prog_name = g_path_get_basename(argv[0]);
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();
exit(EXIT_FAILURE);
}
}
/* Parameter validation */
if ((sock_name == NULL && sock == -1) || rpath == NULL) {
fprintf(stderr, "socket, socket descriptor or path not specified\n");
usage();
return -1;
}
if (sock_name && sock != -1) {
fprintf(stderr, "both named socket and socket descriptor specified\n");
usage();
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();
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;
}
}
if (chroot(rpath) < 0) {
do_perror("chroot");
goto error;
}
if (chdir("/") < 0) {
do_perror("chdir");
goto error;
}
get_version = false;
#ifdef FS_IOC_GETVERSION
/* check whether underlying FS support IOC_GETVERSION */
retval = statfs("/", &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
umask(0);
if (init_capabilities() < 0) {
goto error;
}
process_requests(sock);
error:
g_free(rpath);
g_free(sock_name);
do_log(LOG_INFO, "Done\n");
closelog();
return 0;
}
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