hw/virtio-9p-local.c

   1 /*
   2  * Virtio 9p Posix callback
   3  *
   4  * Copyright IBM, Corp. 2010
   5  *
   6  * Authors:
   7  *  Anthony Liguori   <aliguori@us.ibm.com>
   8  *
   9  * This work is licensed under the terms of the GNU GPL, version 2.  See
  10  * the COPYING file in the top-level directory.
  11  *
  12  */
  13 #include "virtio.h"
  14 #include "virtio-9p.h"
  15 #include <arpa/inet.h>
  16 #include <pwd.h>
  17 #include <grp.h>
  18 #include <sys/socket.h>
  19 #include <sys/un.h>
  20
  21 static const char *rpath(FsContext *ctx, const char *path)
  22 {
  23     /* FIXME: so wrong... */
  24     static char buffer[4096];
  25     snprintf(buffer, sizeof(buffer), "%s/%s", ctx->fs_root, path);
  26     return buffer;
  27 }
  28
  29 static int local_lstat(FsContext *ctx, const char *path, struct stat *stbuf)
  30 {
  31     return lstat(rpath(ctx, path), stbuf);
  32 }
  33
  34 static int local_setuid(FsContext *ctx, uid_t uid)
  35 {
  36     struct passwd *pw;
  37     gid_t groups[33];
  38     int ngroups;
  39     static uid_t cur_uid = -1;
  40
  41     if (cur_uid == uid) {
  42         return 0;
  43     }
  44
  45     if (setreuid(0, 0)) {
  46         return -1;
  47     }
  48
  49     pw = getpwuid(uid);
  50     if (pw == NULL) {
  51         return -1;
  52     }
  53
  54     ngroups = 33;
  55     if (getgrouplist(pw->pw_name, pw->pw_gid, groups, &ngroups) == -1) {
  56         return -1;
  57     }
  58
  59     if (setgroups(ngroups, groups)) {
  60         return -1;
  61     }
  62
  63     if (setregid(-1, pw->pw_gid)) {
  64         return -1;
  65     }
  66
  67     if (setreuid(-1, uid)) {
  68         return -1;
  69     }
  70
  71     cur_uid = uid;
  72
  73     return 0;
  74 }
  75
  76 static ssize_t local_readlink(FsContext *ctx, const char *path,
  77                                 char *buf, size_t bufsz)
  78 {
  79     return readlink(rpath(ctx, path), buf, bufsz);
  80 }
  81
  82 static int local_close(FsContext *ctx, int fd)
  83 {
  84     return close(fd);
  85 }
  86
  87 static int local_closedir(FsContext *ctx, DIR *dir)
  88 {
  89     return closedir(dir);
  90 }
  91
  92 static int local_open(FsContext *ctx, const char *path, int flags)
  93 {
  94     return open(rpath(ctx, path), flags);
  95 }
  96
  97 static DIR *local_opendir(FsContext *ctx, const char *path)
  98 {
  99     return opendir(rpath(ctx, path));
 100 }
 101
 102 static void local_rewinddir(FsContext *ctx, DIR *dir)
 103 {
 104     return rewinddir(dir);
 105 }
 106
 107 static off_t local_telldir(FsContext *ctx, DIR *dir)
 108 {
 109     return telldir(dir);
 110 }
 111
 112 static struct dirent *local_readdir(FsContext *ctx, DIR *dir)
 113 {
 114     return readdir(dir);
 115 }
 116
 117 static void local_seekdir(FsContext *ctx, DIR *dir, off_t off)
 118 {
 119     return seekdir(dir, off);
 120 }
 121
 122 static ssize_t local_readv(FsContext *ctx, int fd, const struct iovec *iov,
 123                             int iovcnt)
 124 {
 125     return readv(fd, iov, iovcnt);
 126 }
 127
 128 static off_t local_lseek(FsContext *ctx, int fd, off_t offset, int whence)
 129 {
 130     return lseek(fd, offset, whence);
 131 }
 132
 133 static ssize_t local_writev(FsContext *ctx, int fd, const struct iovec *iov,
 134                             int iovcnt)
 135 {
 136     return writev(fd, iov, iovcnt);
 137 }
 138
 139 static int local_chmod(FsContext *ctx, const char *path, mode_t mode)
 140 {
 141     return chmod(rpath(ctx, path), mode);
 142 }
 143
 144 static int local_mknod(FsContext *ctx, const char *path, mode_t mode, dev_t dev)
 145 {
 146     return mknod(rpath(ctx, path), mode, dev);
 147 }
 148
 149 static int local_mksock(FsContext *ctx2, const char *path)
 150 {
 151     struct sockaddr_un addr;
 152     int s;
 153
 154     addr.sun_family = AF_UNIX;
 155     snprintf(addr.sun_path, 108, "%s", rpath(ctx2, path));
 156
 157     s = socket(PF_UNIX, SOCK_STREAM, 0);
 158     if (s == -1) {
 159         return -1;
 160     }
 161
 162     if (bind(s, (struct sockaddr *)&addr, sizeof(addr))) {
 163         close(s);
 164         return -1;
 165     }
 166
 167     close(s);
 168     return 0;
 169 }
 170
 171 static int local_mkdir(FsContext *ctx, const char *path, mode_t mode)
 172 {
 173     return mkdir(rpath(ctx, path), mode);
 174 }
 175
 176 static int local_fstat(FsContext *ctx, int fd, struct stat *stbuf)
 177 {
 178     return fstat(fd, stbuf);
 179 }
 180
 181 static int local_open2(FsContext *ctx, const char *path, int flags, mode_t mode)
 182 {
 183     return open(rpath(ctx, path), flags, mode);
 184 }
 185
 186 static int local_symlink(FsContext *ctx, const char *oldpath,
 187                             const char *newpath)
 188 {
 189     return symlink(oldpath, rpath(ctx, newpath));
 190 }
 191
 192 static int local_link(FsContext *ctx, const char *oldpath, const char *newpath)
 193 {
 194     char *tmp = qemu_strdup(rpath(ctx, oldpath));
 195     int err, serrno = 0;
 196
 197     if (tmp == NULL) {
 198         return -ENOMEM;
 199     }
 200
 201     err = link(tmp, rpath(ctx, newpath));
 202     if (err == -1) {
 203         serrno = errno;
 204     }
 205
 206     qemu_free(tmp);
 207
 208     if (err == -1) {
 209         errno = serrno;
 210     }
 211
 212     return err;
 213 }
 214
 215 static int local_truncate(FsContext *ctx, const char *path, off_t size)
 216 {
 217     return truncate(rpath(ctx, path), size);
 218 }
 219
 220 static int local_rename(FsContext *ctx, const char *oldpath,
 221                         const char *newpath)
 222 {
 223     char *tmp;
 224     int err;
 225
 226     tmp = qemu_strdup(rpath(ctx, oldpath));
 227     if (tmp == NULL) {
 228         return -1;
 229     }
 230
 231     err = rename(tmp, rpath(ctx, newpath));
 232     if (err == -1) {
 233         int serrno = errno;
 234         qemu_free(tmp);
 235         errno = serrno;
 236     } else {
 237         qemu_free(tmp);
 238     }
 239
 240     return err;
 241
 242 }
 243
 244 static int local_chown(FsContext *ctx, const char *path, uid_t uid, gid_t gid)
 245 {
 246     return chown(rpath(ctx, path), uid, gid);
 247 }
 248
 249 static int local_utime(FsContext *ctx, const char *path,
 250                         const struct utimbuf *buf)
 251 {
 252     return utime(rpath(ctx, path), buf);
 253 }
 254
 255 static int local_remove(FsContext *ctx, const char *path)
 256 {
 257     return remove(rpath(ctx, path));
 258 }
 259
 260 static int local_fsync(FsContext *ctx, int fd)
 261 {
 262     return fsync(fd);
 263 }
 264
 265 FileOperations local_ops = {
 266     .lstat = local_lstat,
 267     .setuid = local_setuid,
 268     .readlink = local_readlink,
 269     .close = local_close,
 270     .closedir = local_closedir,
 271     .open = local_open,
 272     .opendir = local_opendir,
 273     .rewinddir = local_rewinddir,
 274     .telldir = local_telldir,
 275     .readdir = local_readdir,
 276     .seekdir = local_seekdir,
 277     .readv = local_readv,
 278     .lseek = local_lseek,
 279     .writev = local_writev,
 280     .chmod = local_chmod,
 281     .mknod = local_mknod,
 282     .mksock = local_mksock,
 283     .mkdir = local_mkdir,
 284     .fstat = local_fstat,
 285     .open2 = local_open2,
 286     .symlink = local_symlink,
 287     .link = local_link,
 288     .truncate = local_truncate,
 289     .rename = local_rename,
 290     .chown = local_chown,
 291     .utime = local_utime,
 292     .remove = local_remove,
 293     .fsync = local_fsync,
 294 };