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 2 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, write to the Free Software
  18    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  19 */
  20
  21 #include "includes.h"
  22
  23 struct packet_context {
  24         int fd;
  25         struct data_blob in, out;
  26 };
  27
  28 /*
  29  * Close the underlying fd
  30  */
  31 static int packet_context_destructor(struct packet_context *ctx)
  32 {
  33         return close(ctx->fd);
  34 }
  35
  36 /*
  37  * Initialize a packet context. The fd is given to the packet context, meaning
  38  * that it is automatically closed when the packet context is freed.
  39  */
  40 struct packet_context *packet_init(TALLOC_CTX *mem_ctx, int fd)
  41 {
  42         struct packet_context *result;
  43
  44         if (!(result = TALLOC_ZERO_P(mem_ctx, struct packet_context))) {
  45                 return NULL;
  46         }
  47
  48         result->fd = fd;
  49         talloc_set_destructor(result, packet_context_destructor);
  50         return result;
  51 }
  52
  53 /*
  54  * Pull data from the fd
  55  */
  56 NTSTATUS packet_fd_read(struct packet_context *ctx)
  57 {
  58         int res, available;
  59         size_t new_size;
  60         uint8 *in;
  61
  62         res = ioctl(ctx->fd, FIONREAD, &available);
  63
  64         if (res == -1) {
  65                 DEBUG(10, ("ioctl(FIONREAD) failed: %s\n", strerror(errno)));
  66                 return map_nt_error_from_unix(errno);
  67         }
  68
  69         SMB_ASSERT(available >= 0);
  70
  71         if (available == 0) {
  72                 return NT_STATUS_END_OF_FILE;
  73         }
  74
  75         new_size = ctx->in.length + available;
  76
  77         if (new_size < ctx->in.length) {
  78                 DEBUG(0, ("integer wrap\n"));
  79                 return NT_STATUS_NO_MEMORY;
  80         }
  81
  82         if (!(in = TALLOC_REALLOC_ARRAY(ctx, ctx->in.data, uint8, new_size))) {
  83                 DEBUG(10, ("talloc failed\n"));
  84                 return NT_STATUS_NO_MEMORY;
  85         }
  86
  87         res = recv(ctx->fd, in + ctx->in.length, available, 0);
  88
  89         if (res < 0) {
  90                 DEBUG(10, ("recv failed: %s\n", strerror(errno)));
  91                 return map_nt_error_from_unix(errno);
  92         }
  93
  94         if (res == 0) {
  95                 return NT_STATUS_END_OF_FILE;
  96         }
  97
  98         ctx->in.data = in;
  99         ctx->in.length += available;
 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 = ctx->in.data;
 141         data.length = length;
 142
 143         *status = callback(&data, private_data);
 144
 145         memmove(ctx->in.data, ctx->in.data + length,
 146                 ctx->in.length - length);
 147         ctx->in.length -= length;
 148
 149         return True;
 150 }
 151
 152 /*
 153  * How many bytes of outgoing data do we have pending?
 154  */
 155 size_t packet_outgoing_bytes(struct packet_context *ctx)
 156 {
 157         return ctx->out.length;
 158 }
 159
 160 /*
 161  * Push data to the fd
 162  */
 163 NTSTATUS packet_fd_write(struct packet_context *ctx)
 164 {
 165         ssize_t sent;
 166
 167         sent = send(ctx->fd, ctx->out.data, ctx->out.length, 0);
 168
 169         if (sent == -1) {
 170                 DEBUG(0, ("send failed: %s\n", strerror(errno)));
 171                 return map_nt_error_from_unix(errno);
 172         }
 173
 174         memmove(ctx->out.data, ctx->out.data + sent,
 175                 ctx->out.length - sent);
 176         ctx->out.length -= sent;
 177
 178         return NT_STATUS_OK;
 179 }
 180
 181 /*
 182  * Sync flush all outgoing bytes
 183  */
 184 NTSTATUS packet_flush(struct packet_context *ctx)
 185 {
 186         while (ctx->out.length != 0) {
 187                 NTSTATUS status = packet_fd_write(ctx);
 188                 if (!NT_STATUS_IS_OK(status)) {
 189                         return status;
 190                 }
 191         }
 192         return NT_STATUS_OK;
 193 }
 194
 195 /*
 196  * Send a list of DATA_BLOBs
 197  *
 198  * Example:  packet_send(ctx, 2, data_blob_const(&size, sizeof(size)),
 199  *                       data_blob_const(buf, size));
 200  */
 201 NTSTATUS packet_send(struct packet_context *ctx, int num_blobs, ...)
 202 {
 203         va_list ap;
 204         int i;
 205         size_t len;
 206         uint8 *out;
 207
 208         len = ctx->out.length;
 209
 210         va_start(ap, num_blobs);
 211         for (i=0; i<num_blobs; i++) {
 212                 size_t tmp;
 213                 struct data_blob blob = va_arg(ap, struct data_blob);
 214
 215                 tmp = len + blob.length;
 216                 if (tmp < len) {
 217                         DEBUG(0, ("integer overflow\n"));
 218                         va_end(ap);
 219                         return NT_STATUS_NO_MEMORY;
 220                 }
 221                 len = tmp;
 222         }
 223         va_end(ap);
 224
 225         if (len == 0) {
 226                 return NT_STATUS_OK;
 227         }
 228
 229         if (!(out = TALLOC_REALLOC_ARRAY(ctx, ctx->out.data, uint8, len))) {
 230                 DEBUG(0, ("talloc failed\n"));
 231                 return NT_STATUS_NO_MEMORY;
 232         }
 233
 234         ctx->out.data = out;
 235
 236         va_start(ap, num_blobs);
 237         for (i=0; i<num_blobs; i++) {
 238                 struct data_blob blob = va_arg(ap, struct data_blob);
 239
 240                 memcpy(ctx->out.data+ctx->out.length, blob.data, blob.length);
 241                 ctx->out.length += blob.length;
 242         }
 243         va_end(ap);
 244
 245         SMB_ASSERT(ctx->out.length == len);
 246         return NT_STATUS_OK;
 247 }
 248
 249 /*
 250  * Get the packet context's file descriptor
 251  */
 252 int packet_get_fd(struct packet_context *ctx)
 253 {
 254         return ctx->fd;
 255 }
 256