source/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         struct 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 {
 106         int res;
 107         fd_set r_fds;
 108
 109         FD_ZERO(&r_fds);
 110         FD_SET(ctx->fd, &r_fds);
 111
 112         res = sys_select(ctx->fd+1, &r_fds, NULL, NULL, NULL);
 113
 114         if (res == -1) {
 115                 DEBUG(10, ("select returned %s\n", strerror(errno)));
 116                 return map_nt_error_from_unix(errno);
 117         }
 118
 119         return packet_fd_read(ctx);
 120 }
 121
 122 bool packet_handler(struct packet_context *ctx,
 123                     bool (*full_req)(const struct data_blob *data,
 124                                      size_t *length,
 125                                      void *private_data),
 126                     NTSTATUS (*callback)(const struct data_blob *data,
 127                                          void *private_data),
 128                     void *private_data,
 129                     NTSTATUS *status)
 130 {
 131         size_t length;
 132         struct data_blob data;
 133
 134         if (!full_req(&ctx->in, &length, private_data)) {
 135                 return False;
 136         }
 137
 138         SMB_ASSERT(length <= ctx->in.length);
 139
 140         data = data_blob(ctx->in.data, length);
 141
 142         memmove(ctx->in.data, ctx->in.data + length,
 143                 ctx->in.length - length);
 144         ctx->in.length -= length;
 145
 146         *status = callback(&data, private_data);
 147
 148         data_blob_free(&data);
 149
 150         return True;
 151 }
 152
 153 /*
 154  * How many bytes of outgoing data do we have pending?
 155  */
 156 size_t packet_outgoing_bytes(struct packet_context *ctx)
 157 {
 158         return ctx->out.length;
 159 }
 160
 161 /*
 162  * Push data to the fd
 163  */
 164 NTSTATUS packet_fd_write(struct packet_context *ctx)
 165 {
 166         ssize_t sent;
 167
 168         sent = send(ctx->fd, ctx->out.data, ctx->out.length, 0);
 169
 170         if (sent == -1) {
 171                 DEBUG(0, ("send failed: %s\n", strerror(errno)));
 172                 return map_nt_error_from_unix(errno);
 173         }
 174
 175         memmove(ctx->out.data, ctx->out.data + sent,
 176                 ctx->out.length - sent);
 177         ctx->out.length -= sent;
 178
 179         return NT_STATUS_OK;
 180 }
 181
 182 /*
 183  * Sync flush all outgoing bytes
 184  */
 185 NTSTATUS packet_flush(struct packet_context *ctx)
 186 {
 187         while (ctx->out.length != 0) {
 188                 NTSTATUS status = packet_fd_write(ctx);
 189                 if (!NT_STATUS_IS_OK(status)) {
 190                         return status;
 191                 }
 192         }
 193         return NT_STATUS_OK;
 194 }
 195
 196 /*
 197  * Send a list of DATA_BLOBs
 198  *
 199  * Example:  packet_send(ctx, 2, data_blob_const(&size, sizeof(size)),
 200  *                       data_blob_const(buf, size));
 201  */
 202 NTSTATUS packet_send(struct packet_context *ctx, int num_blobs, ...)
 203 {
 204         va_list ap;
 205         int i;
 206         size_t len;
 207         uint8 *out;
 208
 209         len = ctx->out.length;
 210
 211         va_start(ap, num_blobs);
 212         for (i=0; i<num_blobs; i++) {
 213                 size_t tmp;
 214                 struct data_blob blob = va_arg(ap, struct data_blob);
 215
 216                 tmp = len + blob.length;
 217                 if (tmp < len) {
 218                         DEBUG(0, ("integer overflow\n"));
 219                         va_end(ap);
 220                         return NT_STATUS_NO_MEMORY;
 221                 }
 222                 len = tmp;
 223         }
 224         va_end(ap);
 225
 226         if (len == 0) {
 227                 return NT_STATUS_OK;
 228         }
 229
 230         if (!(out = TALLOC_REALLOC_ARRAY(ctx, ctx->out.data, uint8, len))) {
 231                 DEBUG(0, ("talloc failed\n"));
 232                 return NT_STATUS_NO_MEMORY;
 233         }
 234
 235         ctx->out.data = out;
 236
 237         va_start(ap, num_blobs);
 238         for (i=0; i<num_blobs; i++) {
 239                 struct data_blob blob = va_arg(ap, struct data_blob);
 240
 241                 memcpy(ctx->out.data+ctx->out.length, blob.data, blob.length);
 242                 ctx->out.length += blob.length;
 243         }
 244         va_end(ap);
 245
 246         SMB_ASSERT(ctx->out.length == len);
 247         return NT_STATUS_OK;
 248 }
 249
 250 /*
 251  * Get the packet context's file descriptor
 252  */
 253 int packet_get_fd(struct packet_context *ctx)
 254 {
 255         return ctx->fd;
 256 }
 257