fsdev/virtio-9p-marshal.c

   1 /*
   2  * Virtio 9p backend
   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
  14 #include <glib.h>
  15 #include <glib/gprintf.h>
  16 #include <sys/types.h>
  17 #include <sys/time.h>
  18 #include <utime.h>
  19 #include <sys/uio.h>
  20 #include <string.h>
  21 #include <stdint.h>
  22 #include <errno.h>
  23
  24 #include "qemu/compiler.h"
  25 #include "virtio-9p-marshal.h"
  26 #include "qemu/bswap.h"
  27
  28 void v9fs_string_free(V9fsString *str)
  29 {
  30     g_free(str->data);
  31     str->data = NULL;
  32     str->size = 0;
  33 }
  34
  35 void v9fs_string_null(V9fsString *str)
  36 {
  37     v9fs_string_free(str);
  38 }
  39
  40 void GCC_FMT_ATTR(2, 3)
  41 v9fs_string_sprintf(V9fsString *str, const char *fmt, ...)
  42 {
  43     va_list ap;
  44
  45     v9fs_string_free(str);
  46
  47     va_start(ap, fmt);
  48     str->size = g_vasprintf(&str->data, fmt, ap);
  49     va_end(ap);
  50 }
  51
  52 void v9fs_string_copy(V9fsString *lhs, V9fsString *rhs)
  53 {
  54     v9fs_string_free(lhs);
  55     v9fs_string_sprintf(lhs, "%s", rhs->data);
  56 }
  57
  58
  59 static ssize_t v9fs_packunpack(void *addr, struct iovec *sg, int sg_count,
  60                                size_t offset, size_t size, int pack)
  61 {
  62     int i = 0;
  63     size_t copied = 0;
  64     size_t req_size = size;
  65
  66
  67     for (i = 0; size && i < sg_count; i++) {
  68         size_t len;
  69         if (offset >= sg[i].iov_len) {
  70             /* skip this sg */
  71             offset -= sg[i].iov_len;
  72             continue;
  73         } else {
  74             len = MIN(sg[i].iov_len - offset, size);
  75             if (pack) {
  76                 memcpy(sg[i].iov_base + offset, addr, len);
  77             } else {
  78                 memcpy(addr, sg[i].iov_base + offset, len);
  79             }
  80             size -= len;
  81             copied += len;
  82             addr += len;
  83             if (size) {
  84                 offset = 0;
  85                 continue;
  86             }
  87         }
  88     }
  89     if (copied < req_size) {
  90         /*
  91          * We copied less that requested size. error out
  92          */
  93         return -ENOBUFS;
  94     }
  95     return copied;
  96 }
  97
  98 static ssize_t v9fs_unpack(void *dst, struct iovec *out_sg, int out_num,
  99                            size_t offset, size_t size)
 100 {
 101     return v9fs_packunpack(dst, out_sg, out_num, offset, size, 0);
 102 }
 103
 104 ssize_t v9fs_pack(struct iovec *in_sg, int in_num, size_t offset,
 105                   const void *src, size_t size)
 106 {
 107     return v9fs_packunpack((void *)src, in_sg, in_num, offset, size, 1);
 108 }
 109
 110 ssize_t v9fs_unmarshal(struct iovec *out_sg, int out_num, size_t offset,
 111                        int bswap, const char *fmt, ...)
 112 {
 113     int i;
 114     va_list ap;
 115     ssize_t copied = 0;
 116     size_t old_offset = offset;
 117
 118     va_start(ap, fmt);
 119     for (i = 0; fmt[i]; i++) {
 120         switch (fmt[i]) {
 121         case 'b': {
 122             uint8_t *valp = va_arg(ap, uint8_t *);
 123             copied = v9fs_unpack(valp, out_sg, out_num, offset, sizeof(*valp));
 124             break;
 125         }
 126         case 'w': {
 127             uint16_t val, *valp;
 128             valp = va_arg(ap, uint16_t *);
 129             copied = v9fs_unpack(&val, out_sg, out_num, offset, sizeof(val));
 130             if (bswap) {
 131                 *valp = le16_to_cpu(val);
 132             } else {
 133                 *valp = val;
 134             }
 135             break;
 136         }
 137         case 'd': {
 138             uint32_t val, *valp;
 139             valp = va_arg(ap, uint32_t *);
 140             copied = v9fs_unpack(&val, out_sg, out_num, offset, sizeof(val));
 141             if (bswap) {
 142                 *valp = le32_to_cpu(val);
 143             } else {
 144                 *valp = val;
 145             }
 146             break;
 147         }
 148         case 'q': {
 149             uint64_t val, *valp;
 150             valp = va_arg(ap, uint64_t *);
 151             copied = v9fs_unpack(&val, out_sg, out_num, offset, sizeof(val));
 152             if (bswap) {
 153                 *valp = le64_to_cpu(val);
 154             } else {
 155                 *valp = val;
 156             }
 157             break;
 158         }
 159         case 's': {
 160             V9fsString *str = va_arg(ap, V9fsString *);
 161             copied = v9fs_unmarshal(out_sg, out_num, offset, bswap,
 162                                     "w", &str->size);
 163             if (copied > 0) {
 164                 offset += copied;
 165                 str->data = g_malloc(str->size + 1);
 166                 copied = v9fs_unpack(str->data, out_sg, out_num, offset,
 167                                      str->size);
 168                 if (copied > 0) {
 169                     str->data[str->size] = 0;
 170                 } else {
 171                     v9fs_string_free(str);
 172                 }
 173             }
 174             break;
 175         }
 176         case 'Q': {
 177             V9fsQID *qidp = va_arg(ap, V9fsQID *);
 178             copied = v9fs_unmarshal(out_sg, out_num, offset, bswap, "bdq",
 179                                     &qidp->type, &qidp->version, &qidp->path);
 180             break;
 181         }
 182         case 'S': {
 183             V9fsStat *statp = va_arg(ap, V9fsStat *);
 184             copied = v9fs_unmarshal(out_sg, out_num, offset, bswap,
 185                                     "wwdQdddqsssssddd",
 186                                     &statp->size, &statp->type, &statp->dev,
 187                                     &statp->qid, &statp->mode, &statp->atime,
 188                                     &statp->mtime, &statp->length,
 189                                     &statp->name, &statp->uid, &statp->gid,
 190                                     &statp->muid, &statp->extension,
 191                                     &statp->n_uid, &statp->n_gid,
 192                                     &statp->n_muid);
 193             break;
 194         }
 195         case 'I': {
 196             V9fsIattr *iattr = va_arg(ap, V9fsIattr *);
 197             copied = v9fs_unmarshal(out_sg, out_num, offset, bswap,
 198                                     "ddddqqqqq",
 199                                     &iattr->valid, &iattr->mode,
 200                                     &iattr->uid, &iattr->gid, &iattr->size,
 201                                     &iattr->atime_sec, &iattr->atime_nsec,
 202                                     &iattr->mtime_sec, &iattr->mtime_nsec);
 203             break;
 204         }
 205         default:
 206             break;
 207         }
 208         if (copied < 0) {
 209             va_end(ap);
 210             return copied;
 211         }
 212         offset += copied;
 213     }
 214     va_end(ap);
 215
 216     return offset - old_offset;
 217 }
 218
 219 ssize_t v9fs_marshal(struct iovec *in_sg, int in_num, size_t offset,
 220                      int bswap, const char *fmt, ...)
 221 {
 222     int i;
 223     va_list ap;
 224     ssize_t copied = 0;
 225     size_t old_offset = offset;
 226
 227     va_start(ap, fmt);
 228     for (i = 0; fmt[i]; i++) {
 229         switch (fmt[i]) {
 230         case 'b': {
 231             uint8_t val = va_arg(ap, int);
 232             copied = v9fs_pack(in_sg, in_num, offset, &val, sizeof(val));
 233             break;
 234         }
 235         case 'w': {
 236             uint16_t val;
 237             if (bswap) {
 238                 cpu_to_le16w(&val, va_arg(ap, int));
 239             } else {
 240                 val =  va_arg(ap, int);
 241             }
 242             copied = v9fs_pack(in_sg, in_num, offset, &val, sizeof(val));
 243             break;
 244         }
 245         case 'd': {
 246             uint32_t val;
 247             if (bswap) {
 248                 cpu_to_le32w(&val, va_arg(ap, uint32_t));
 249             } else {
 250                 val =  va_arg(ap, uint32_t);
 251             }
 252             copied = v9fs_pack(in_sg, in_num, offset, &val, sizeof(val));
 253             break;
 254         }
 255         case 'q': {
 256             uint64_t val;
 257             if (bswap) {
 258                 cpu_to_le64w(&val, va_arg(ap, uint64_t));
 259             } else {
 260                 val =  va_arg(ap, uint64_t);
 261             }
 262             copied = v9fs_pack(in_sg, in_num, offset, &val, sizeof(val));
 263             break;
 264         }
 265         case 's': {
 266             V9fsString *str = va_arg(ap, V9fsString *);
 267             copied = v9fs_marshal(in_sg, in_num, offset, bswap,
 268                                   "w", str->size);
 269             if (copied > 0) {
 270                 offset += copied;
 271                 copied = v9fs_pack(in_sg, in_num, offset, str->data, str->size);
 272             }
 273             break;
 274         }
 275         case 'Q': {
 276             V9fsQID *qidp = va_arg(ap, V9fsQID *);
 277             copied = v9fs_marshal(in_sg, in_num, offset, bswap, "bdq",
 278                                   qidp->type, qidp->version, qidp->path);
 279             break;
 280         }
 281         case 'S': {
 282             V9fsStat *statp = va_arg(ap, V9fsStat *);
 283             copied = v9fs_marshal(in_sg, in_num, offset, bswap,
 284                                   "wwdQdddqsssssddd",
 285                                   statp->size, statp->type, statp->dev,
 286                                   &statp->qid, statp->mode, statp->atime,
 287                                   statp->mtime, statp->length, &statp->name,
 288                                   &statp->uid, &statp->gid, &statp->muid,
 289                                   &statp->extension, statp->n_uid,
 290                                   statp->n_gid, statp->n_muid);
 291             break;
 292         }
 293         case 'A': {
 294             V9fsStatDotl *statp = va_arg(ap, V9fsStatDotl *);
 295             copied = v9fs_marshal(in_sg, in_num, offset, bswap,
 296                                    "qQdddqqqqqqqqqqqqqqq",
 297                                    statp->st_result_mask,
 298                                    &statp->qid, statp->st_mode,
 299                                    statp->st_uid, statp->st_gid,
 300                                    statp->st_nlink, statp->st_rdev,
 301                                    statp->st_size, statp->st_blksize,
 302                                    statp->st_blocks, statp->st_atime_sec,
 303                                    statp->st_atime_nsec, statp->st_mtime_sec,
 304                                    statp->st_mtime_nsec, statp->st_ctime_sec,
 305                                    statp->st_ctime_nsec, statp->st_btime_sec,
 306                                    statp->st_btime_nsec, statp->st_gen,
 307                                    statp->st_data_version);
 308             break;
 309         }
 310         default:
 311             break;
 312         }
 313         if (copied < 0) {
 314             va_end(ap);
 315             return copied;
 316         }
 317         offset += copied;
 318     }
 319     va_end(ap);
 320
 321     return offset - old_offset;
 322 }