source3/lib/packet.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    Packet handling
   4    Copyright (C) Volker Lendecke 2007
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 3 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18 */
  19
  20 #include "includes.h"
  21
  22 struct packet_context {
  23         int fd;
  24         DATA_BLOB in, out;
  25 };
  26
  27 /*
  28  * Close the underlying fd
  29  */
  30 static int packet_context_destructor(struct packet_context *ctx)
  31 {
  32         return close(ctx->fd);
  33 }
  34
  35 /*
  36  * Initialize a packet context. The fd is given to the packet context, meaning
  37  * that it is automatically closed when the packet context is freed.
  38  */
  39 struct packet_context *packet_init(TALLOC_CTX *mem_ctx, int fd)
  40 {
  41         struct packet_context *result;
  42
  43         if (!(result = TALLOC_ZERO_P(mem_ctx, struct packet_context))) {
  44                 return NULL;
  45         }
  46
  47         result->fd = fd;
  48         talloc_set_destructor(result, packet_context_destructor);
  49         return result;
  50 }
  51
  52 /*
  53  * Pull data from the fd
  54  */
  55 NTSTATUS packet_fd_read(struct packet_context *ctx)
  56 {
  57         int res, available;
  58         size_t new_size;
  59         uint8 *in;
  60
  61         res = ioctl(ctx->fd, FIONREAD, &available);
  62
  63         if (res == -1) {
  64                 DEBUG(10, ("ioctl(FIONREAD) failed: %s\n", strerror(errno)));
  65                 return map_nt_error_from_unix(errno);
  66         }
  67
  68         SMB_ASSERT(available >= 0);
  69
  70         if (available == 0) {
  71                 return NT_STATUS_END_OF_FILE;
  72         }
  73
  74         new_size = ctx->in.length + available;
  75
  76         if (new_size < ctx->in.length) {
  77                 DEBUG(0, ("integer wrap\n"));
  78                 return NT_STATUS_NO_MEMORY;
  79         }
  80
  81         if (!(in = TALLOC_REALLOC_ARRAY(ctx, ctx->in.data, uint8, new_size))) {
  82                 DEBUG(10, ("talloc failed\n"));
  83                 return NT_STATUS_NO_MEMORY;
  84         }
  85
  86         ctx->in.data = in;
  87
  88         res = recv(ctx->fd, in + ctx->in.length, available, 0);
  89
  90         if (res < 0) {
  91                 DEBUG(10, ("recv failed: %s\n", strerror(errno)));
  92                 return map_nt_error_from_unix(errno);
  93         }
  94
  95         if (res == 0) {
  96                 return NT_STATUS_END_OF_FILE;
  97         }
  98
  99         ctx->in.length += res;
 100
 101         return NT_STATUS_OK;
 102 }
 103
 104 NTSTATUS packet_fd_read_sync(struct packet_context *ctx,
 105                              struct timeval *timeout)
 106 {
 107         int res;
 108         fd_set r_fds;
 109
 110         FD_ZERO(&r_fds);
 111         FD_SET(ctx->fd, &r_fds);
 112
 113         res = sys_select(ctx->fd+1, &r_fds, NULL, NULL, timeout);
 114
 115         if (res == 0) {
 116                 DEBUG(10, ("select timed out\n"));
 117                 return NT_STATUS_IO_TIMEOUT;
 118         }
 119
 120         if (res == -1) {
 121                 DEBUG(10, ("select returned %s\n", strerror(errno)));
 122                 return map_nt_error_from_unix(errno);
 123         }
 124
 125         return packet_fd_read(ctx);
 126 }
 127
 128 bool packet_handler(struct packet_context *ctx,
 129                     bool (*full_req)(const uint8_t *buf,
 130                                      size_t available,
 131                                      size_t *length,
 132                                      void *priv),
 133                     NTSTATUS (*callback)(uint8_t *buf, size_t length,
 134                                          void *priv),
 135                     void *priv, NTSTATUS *status)
 136 {
 137         size_t length;
 138         uint8_t *buf;
 139
 140         if (!full_req(ctx->in.data, ctx->in.length, &length, priv)) {
 141                 return False;
 142         }
 143
 144         if (length > ctx->in.length) {
 145                 *status = NT_STATUS_INTERNAL_ERROR;
 146                 return true;
 147         }
 148
 149         if (length == ctx->in.length) {
 150                 buf = ctx->in.data;
 151                 ctx->in.data = NULL;
 152                 ctx->in.length = 0;
 153         } else {
 154                 buf = (uint8_t *)TALLOC_MEMDUP(ctx, ctx->in.data, length);
 155                 if (buf == NULL) {
 156                         *status = NT_STATUS_NO_MEMORY;
 157                         return true;
 158                 }
 159
 160                 memmove(ctx->in.data, ctx->in.data + length,
 161                         ctx->in.length - length);
 162                 ctx->in.length -= length;
 163         }
 164
 165         *status = callback(buf, length, priv);
 166         return True;
 167 }
 168
 169 /*
 170  * How many bytes of outgoing data do we have pending?
 171  */
 172 size_t packet_outgoing_bytes(struct packet_context *ctx)
 173 {
 174         return ctx->out.length;
 175 }
 176
 177 /*
 178  * Push data to the fd
 179  */
 180 NTSTATUS packet_fd_write(struct packet_context *ctx)
 181 {
 182         ssize_t sent;
 183
 184         sent = send(ctx->fd, ctx->out.data, ctx->out.length, 0);
 185
 186         if (sent == -1) {
 187                 DEBUG(0, ("send failed: %s\n", strerror(errno)));
 188                 return map_nt_error_from_unix(errno);
 189         }
 190
 191         memmove(ctx->out.data, ctx->out.data + sent,
 192                 ctx->out.length - sent);
 193         ctx->out.length -= sent;
 194
 195         return NT_STATUS_OK;
 196 }
 197
 198 /*
 199  * Sync flush all outgoing bytes
 200  */
 201 NTSTATUS packet_flush(struct packet_context *ctx)
 202 {
 203         while (ctx->out.length != 0) {
 204                 NTSTATUS status = packet_fd_write(ctx);
 205                 if (!NT_STATUS_IS_OK(status)) {
 206                         return status;
 207                 }
 208         }
 209         return NT_STATUS_OK;
 210 }
 211
 212 /*
 213  * Send a list of DATA_BLOBs
 214  *
 215  * Example:  packet_send(ctx, 2, data_blob_const(&size, sizeof(size)),
 216  *                       data_blob_const(buf, size));
 217  */
 218 NTSTATUS packet_send(struct packet_context *ctx, int num_blobs, ...)
 219 {
 220         va_list ap;
 221         int i;
 222         size_t len;
 223         uint8 *out;
 224
 225         len = ctx->out.length;
 226
 227         va_start(ap, num_blobs);
 228         for (i=0; i<num_blobs; i++) {
 229                 size_t tmp;
 230                 DATA_BLOB blob = va_arg(ap, DATA_BLOB);
 231
 232                 tmp = len + blob.length;
 233                 if (tmp < len) {
 234                         DEBUG(0, ("integer overflow\n"));
 235                         va_end(ap);
 236                         return NT_STATUS_NO_MEMORY;
 237                 }
 238                 len = tmp;
 239         }
 240         va_end(ap);
 241
 242         if (len == 0) {
 243                 return NT_STATUS_OK;
 244         }
 245
 246         if (!(out = TALLOC_REALLOC_ARRAY(ctx, ctx->out.data, uint8, len))) {
 247                 DEBUG(0, ("talloc failed\n"));
 248                 return NT_STATUS_NO_MEMORY;
 249         }
 250
 251         ctx->out.data = out;
 252
 253         va_start(ap, num_blobs);
 254         for (i=0; i<num_blobs; i++) {
 255                 DATA_BLOB blob = va_arg(ap, DATA_BLOB);
 256
 257                 memcpy(ctx->out.data+ctx->out.length, blob.data, blob.length);
 258                 ctx->out.length += blob.length;
 259         }
 260         va_end(ap);
 261
 262         SMB_ASSERT(ctx->out.length == len);
 263         return NT_STATUS_OK;
 264 }
 265
 266 /*
 267  * Get the packet context's file descriptor
 268  */
 269 int packet_get_fd(struct packet_context *ctx)
 270 {
 271         return ctx->fd;
 272 }
 273