fsdev/9p-iov-marshal.c

   1 /*
   2  * 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 "qemu/osdep.h"
  15 #include <glib/gprintf.h>
  16 #include <utime.h>
  17
  18 #include "9p-iov-marshal.h"
  19 #include "qemu/bswap.h"
  20
  21 static ssize_t v9fs_packunpack(void *addr, struct iovec *sg, int sg_count,
  22                                size_t offset, size_t size, int pack)
  23 {
  24     int i = 0;
  25     size_t copied = 0;
  26     size_t req_size = size;
  27
  28
  29     for (i = 0; size && i < sg_count; i++) {
  30         size_t len;
  31         if (offset >= sg[i].iov_len) {
  32             /* skip this sg */
  33             offset -= sg[i].iov_len;
  34             continue;
  35         } else {
  36             len = MIN(sg[i].iov_len - offset, size);
  37             if (pack) {
  38                 memcpy(sg[i].iov_base + offset, addr, len);
  39             } else {
  40                 memcpy(addr, sg[i].iov_base + offset, len);
  41             }
  42             size -= len;
  43             copied += len;
  44             addr += len;
  45             if (size) {
  46                 offset = 0;
  47                 continue;
  48             }
  49         }
  50     }
  51     if (copied < req_size) {
  52         /*
  53          * We copied less that requested size. error out
  54          */
  55         return -ENOBUFS;
  56     }
  57     return copied;
  58 }
  59
  60 static ssize_t v9fs_unpack(void *dst, struct iovec *out_sg, int out_num,
  61                            size_t offset, size_t size)
  62 {
  63     return v9fs_packunpack(dst, out_sg, out_num, offset, size, 0);
  64 }
  65
  66 ssize_t v9fs_pack(struct iovec *in_sg, int in_num, size_t offset,
  67                   const void *src, size_t size)
  68 {
  69     return v9fs_packunpack((void *)src, in_sg, in_num, offset, size, 1);
  70 }
  71
  72 ssize_t v9fs_iov_vunmarshal(struct iovec *out_sg, int out_num, size_t offset,
  73                             int bswap, const char *fmt, va_list ap)
  74 {
  75     int i;
  76     ssize_t copied = 0;
  77     size_t old_offset = offset;
  78
  79     for (i = 0; fmt[i]; i++) {
  80         switch (fmt[i]) {
  81         case 'b': {
  82             uint8_t *valp = va_arg(ap, uint8_t *);
  83             copied = v9fs_unpack(valp, out_sg, out_num, offset, sizeof(*valp));
  84             break;
  85         }
  86         case 'w': {
  87             uint16_t val, *valp;
  88             valp = va_arg(ap, uint16_t *);
  89             copied = v9fs_unpack(&val, out_sg, out_num, offset, sizeof(val));
  90             if (bswap) {
  91                 *valp = le16_to_cpu(val);
  92             } else {
  93                 *valp = val;
  94             }
  95             break;
  96         }
  97         case 'd': {
  98             uint32_t val, *valp;
  99             valp = va_arg(ap, uint32_t *);
 100             copied = v9fs_unpack(&val, out_sg, out_num, offset, sizeof(val));
 101             if (bswap) {
 102                 *valp = le32_to_cpu(val);
 103             } else {
 104                 *valp = val;
 105             }
 106             break;
 107         }
 108         case 'q': {
 109             uint64_t val, *valp;
 110             valp = va_arg(ap, uint64_t *);
 111             copied = v9fs_unpack(&val, out_sg, out_num, offset, sizeof(val));
 112             if (bswap) {
 113                 *valp = le64_to_cpu(val);
 114             } else {
 115                 *valp = val;
 116             }
 117             break;
 118         }
 119         case 's': {
 120             V9fsString *str = va_arg(ap, V9fsString *);
 121             copied = v9fs_iov_unmarshal(out_sg, out_num, offset, bswap,
 122                                         "w", &str->size);
 123             if (copied > 0) {
 124                 offset += copied;
 125                 str->data = g_malloc(str->size + 1);
 126                 copied = v9fs_unpack(str->data, out_sg, out_num, offset,
 127                                      str->size);
 128                 if (copied > 0) {
 129                     str->data[str->size] = 0;
 130                 } else {
 131                     v9fs_string_free(str);
 132                 }
 133             }
 134             break;
 135         }
 136         case 'Q': {
 137             V9fsQID *qidp = va_arg(ap, V9fsQID *);
 138             copied = v9fs_iov_unmarshal(out_sg, out_num, offset, bswap,
 139                                         "bdq", &qidp->type, &qidp->version,
 140                                         &qidp->path);
 141             break;
 142         }
 143         case 'S': {
 144             V9fsStat *statp = va_arg(ap, V9fsStat *);
 145             copied = v9fs_iov_unmarshal(out_sg, out_num, offset, bswap,
 146                                         "wwdQdddqsssssddd",
 147                                         &statp->size, &statp->type,
 148                                         &statp->dev, &statp->qid,
 149                                         &statp->mode, &statp->atime,
 150                                         &statp->mtime, &statp->length,
 151                                         &statp->name, &statp->uid,
 152                                         &statp->gid, &statp->muid,
 153                                         &statp->extension,
 154                                         &statp->n_uid, &statp->n_gid,
 155                                         &statp->n_muid);
 156             break;
 157         }
 158         case 'I': {
 159             V9fsIattr *iattr = va_arg(ap, V9fsIattr *);
 160             copied = v9fs_iov_unmarshal(out_sg, out_num, offset, bswap,
 161                                         "ddddqqqqq",
 162                                         &iattr->valid, &iattr->mode,
 163                                         &iattr->uid, &iattr->gid,
 164                                         &iattr->size, &iattr->atime_sec,
 165                                         &iattr->atime_nsec,
 166                                         &iattr->mtime_sec,
 167                                         &iattr->mtime_nsec);
 168             break;
 169         }
 170         default:
 171             break;
 172         }
 173         if (copied < 0) {
 174             return copied;
 175         }
 176         offset += copied;
 177     }
 178
 179     return offset - old_offset;
 180 }
 181
 182 ssize_t v9fs_iov_unmarshal(struct iovec *out_sg, int out_num, size_t offset,
 183                            int bswap, const char *fmt, ...)
 184 {
 185     ssize_t ret;
 186     va_list ap;
 187
 188     va_start(ap, fmt);
 189     ret = v9fs_iov_vunmarshal(out_sg, out_num, offset, bswap, fmt, ap);
 190     va_end(ap);
 191
 192     return ret;
 193 }
 194
 195 ssize_t v9fs_iov_vmarshal(struct iovec *in_sg, int in_num, size_t offset,
 196                           int bswap, const char *fmt, va_list ap)
 197 {
 198     int i;
 199     ssize_t copied = 0;
 200     size_t old_offset = offset;
 201
 202     for (i = 0; fmt[i]; i++) {
 203         switch (fmt[i]) {
 204         case 'b': {
 205             uint8_t val = va_arg(ap, int);
 206             copied = v9fs_pack(in_sg, in_num, offset, &val, sizeof(val));
 207             break;
 208         }
 209         case 'w': {
 210             uint16_t val = va_arg(ap, int);
 211             if (bswap) {
 212                 val = cpu_to_le16(val);
 213             }
 214             copied = v9fs_pack(in_sg, in_num, offset, &val, sizeof(val));
 215             break;
 216         }
 217         case 'd': {
 218             uint32_t val = va_arg(ap, uint32_t);
 219             if (bswap) {
 220                 val = cpu_to_le32(val);
 221             }
 222             copied = v9fs_pack(in_sg, in_num, offset, &val, sizeof(val));
 223             break;
 224         }
 225         case 'q': {
 226             uint64_t val = va_arg(ap, uint64_t);
 227             if (bswap) {
 228                 val = cpu_to_le64(val);
 229             }
 230             copied = v9fs_pack(in_sg, in_num, offset, &val, sizeof(val));
 231             break;
 232         }
 233         case 's': {
 234             V9fsString *str = va_arg(ap, V9fsString *);
 235             copied = v9fs_iov_marshal(in_sg, in_num, offset, bswap,
 236                                       "w", str->size);
 237             if (copied > 0) {
 238                 offset += copied;
 239                 copied = v9fs_pack(in_sg, in_num, offset, str->data, str->size);
 240             }
 241             break;
 242         }
 243         case 'Q': {
 244             V9fsQID *qidp = va_arg(ap, V9fsQID *);
 245             copied = v9fs_iov_marshal(in_sg, in_num, offset, bswap, "bdq",
 246                                       qidp->type, qidp->version,
 247                                       qidp->path);
 248             break;
 249         }
 250         case 'S': {
 251             V9fsStat *statp = va_arg(ap, V9fsStat *);
 252             copied = v9fs_iov_marshal(in_sg, in_num, offset, bswap,
 253                                       "wwdQdddqsssssddd",
 254                                       statp->size, statp->type, statp->dev,
 255                                       &statp->qid, statp->mode, statp->atime,
 256                                       statp->mtime, statp->length,
 257                                       &statp->name,
 258                                       &statp->uid, &statp->gid, &statp->muid,
 259                                       &statp->extension, statp->n_uid,
 260                                       statp->n_gid, statp->n_muid);
 261             break;
 262         }
 263         case 'A': {
 264             V9fsStatDotl *statp = va_arg(ap, V9fsStatDotl *);
 265             copied = v9fs_iov_marshal(in_sg, in_num, offset, bswap,
 266                                       "qQdddqqqqqqqqqqqqqqq",
 267                                       statp->st_result_mask,
 268                                       &statp->qid, statp->st_mode,
 269                                       statp->st_uid, statp->st_gid,
 270                                       statp->st_nlink, statp->st_rdev,
 271                                       statp->st_size, statp->st_blksize,
 272                                       statp->st_blocks, statp->st_atime_sec,
 273                                       statp->st_atime_nsec,
 274                                       statp->st_mtime_sec,
 275                                       statp->st_mtime_nsec,
 276                                       statp->st_ctime_sec,
 277                                       statp->st_ctime_nsec,
 278                                       statp->st_btime_sec,
 279                                       statp->st_btime_nsec, statp->st_gen,
 280                                       statp->st_data_version);
 281             break;
 282         }
 283         default:
 284             break;
 285         }
 286         if (copied < 0) {
 287             return copied;
 288         }
 289         offset += copied;
 290     }
 291
 292     return offset - old_offset;
 293 }
 294
 295 ssize_t v9fs_iov_marshal(struct iovec *in_sg, int in_num, size_t offset,
 296                          int bswap, const char *fmt, ...)
 297 {
 298     ssize_t ret;
 299     va_list ap;
 300
 301     va_start(ap, fmt);
 302     ret = v9fs_iov_vmarshal(in_sg, in_num, offset, bswap, fmt, ap);
 303     va_end(ap);
 304
 305     return ret;
 306 }