source3/lib/ctdb_packet.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    CTDB 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 #include "../lib/util/select.h"
  22 #include "system/filesys.h"
  23 #include "ctdb_packet.h"
  24
  25 struct ctdb_packet_context {
  26         int fd;
  27         DATA_BLOB in, out;
  28 };
  29
  30 /*
  31  * Close the underlying fd
  32  */
  33 static int ctdb_packet_context_destructor(struct ctdb_packet_context *ctx)
  34 {
  35         return close(ctx->fd);
  36 }
  37
  38 /*
  39  * Initialize a ctdb_packet context. The fd is given to the ctdb_packet context, meaning
  40  * that it is automatically closed when the ctdb_packet context is freed.
  41  */
  42 struct ctdb_packet_context *ctdb_packet_init(TALLOC_CTX *mem_ctx, int fd)
  43 {
  44         struct ctdb_packet_context *result;
  45
  46         if (!(result = talloc_zero(mem_ctx, struct ctdb_packet_context))) {
  47                 return NULL;
  48         }
  49
  50         result->fd = fd;
  51         talloc_set_destructor(result, ctdb_packet_context_destructor);
  52         return result;
  53 }
  54
  55 /*
  56  * Pull data from the fd
  57  */
  58 NTSTATUS ctdb_packet_fd_read(struct ctdb_packet_context *ctx)
  59 {
  60         int res, available;
  61         size_t new_size;
  62         uint8 *in;
  63
  64         res = ioctl(ctx->fd, FIONREAD, &available);
  65
  66         if (res == -1) {
  67                 DEBUG(10, ("ioctl(FIONREAD) failed: %s\n", strerror(errno)));
  68                 return map_nt_error_from_unix(errno);
  69         }
  70
  71         SMB_ASSERT(available >= 0);
  72
  73         if (available == 0) {
  74                 return NT_STATUS_END_OF_FILE;
  75         }
  76
  77         new_size = ctx->in.length + available;
  78
  79         if (new_size < ctx->in.length) {
  80                 DEBUG(0, ("integer wrap\n"));
  81                 return NT_STATUS_NO_MEMORY;
  82         }
  83
  84         if (!(in = talloc_realloc(ctx, ctx->in.data, uint8, new_size))) {
  85                 DEBUG(10, ("talloc failed\n"));
  86                 return NT_STATUS_NO_MEMORY;
  87         }
  88
  89         ctx->in.data = in;
  90
  91         res = recv(ctx->fd, in + ctx->in.length, available, 0);
  92
  93         if (res < 0) {
  94                 DEBUG(10, ("recv failed: %s\n", strerror(errno)));
  95                 return map_nt_error_from_unix(errno);
  96         }
  97
  98         if (res == 0) {
  99                 return NT_STATUS_END_OF_FILE;
 100         }
 101
 102         ctx->in.length += res;
 103
 104         return NT_STATUS_OK;
 105 }
 106
 107 NTSTATUS ctdb_packet_fd_read_sync_timeout(struct ctdb_packet_context *ctx, int timeout)
 108 {
 109         int res, revents;
 110
 111         res = poll_one_fd(ctx->fd, POLLIN|POLLHUP, timeout, &revents);
 112         if (res == 0) {
 113                 DEBUG(10, ("poll timed out\n"));
 114                 return NT_STATUS_IO_TIMEOUT;
 115         }
 116
 117         if (res == -1) {
 118                 DEBUG(10, ("poll returned %s\n", strerror(errno)));
 119                 return map_nt_error_from_unix(errno);
 120         }
 121         if ((revents & (POLLIN|POLLHUP|POLLERR)) == 0) {
 122                 DEBUG(10, ("socket not readable\n"));
 123                 return NT_STATUS_IO_TIMEOUT;
 124         }
 125
 126         return ctdb_packet_fd_read(ctx);
 127 }
 128
 129 bool ctdb_packet_handler(struct ctdb_packet_context *ctx,
 130                     bool (*full_req)(const uint8_t *buf,
 131                                      size_t available,
 132                                      size_t *length,
 133                                      void *priv),
 134                     NTSTATUS (*callback)(uint8_t *buf, size_t length,
 135                                          void *priv),
 136                     void *priv, NTSTATUS *status)
 137 {
 138         size_t length;
 139         uint8_t *buf;
 140
 141         if (!full_req(ctx->in.data, ctx->in.length, &length, priv)) {
 142                 return False;
 143         }
 144
 145         if (length > ctx->in.length) {
 146                 *status = NT_STATUS_INTERNAL_ERROR;
 147                 return true;
 148         }
 149
 150         if (length == ctx->in.length) {
 151                 buf = ctx->in.data;
 152                 ctx->in.data = NULL;
 153                 ctx->in.length = 0;
 154         } else {
 155                 buf = (uint8_t *)talloc_memdup(ctx, ctx->in.data, length);
 156                 if (buf == NULL) {
 157                         *status = NT_STATUS_NO_MEMORY;
 158                         return true;
 159                 }
 160
 161                 memmove(ctx->in.data, ctx->in.data + length,
 162                         ctx->in.length - length);
 163                 ctx->in.length -= length;
 164         }
 165
 166         *status = callback(buf, length, priv);
 167         return True;
 168 }
 169
 170 /*
 171  * How many bytes of outgoing data do we have pending?
 172  */
 173 size_t ctdb_packet_outgoing_bytes(struct ctdb_packet_context *ctx)
 174 {
 175         return ctx->out.length;
 176 }
 177
 178 /*
 179  * Push data to the fd
 180  */
 181 NTSTATUS ctdb_packet_fd_write(struct ctdb_packet_context *ctx)
 182 {
 183         ssize_t sent;
 184
 185         sent = sys_send(ctx->fd, ctx->out.data, ctx->out.length, 0);
 186
 187         if (sent == -1) {
 188                 DEBUG(0, ("send failed: %s\n", strerror(errno)));
 189                 return map_nt_error_from_unix(errno);
 190         }
 191
 192         memmove(ctx->out.data, ctx->out.data + sent,
 193                 ctx->out.length - sent);
 194         ctx->out.length -= sent;
 195
 196         return NT_STATUS_OK;
 197 }
 198
 199 /*
 200  * Sync flush all outgoing bytes
 201  */
 202 NTSTATUS ctdb_packet_flush(struct ctdb_packet_context *ctx)
 203 {
 204         while (ctx->out.length != 0) {
 205                 NTSTATUS status = ctdb_packet_fd_write(ctx);
 206                 if (!NT_STATUS_IS_OK(status)) {
 207                         return status;
 208                 }
 209         }
 210         return NT_STATUS_OK;
 211 }
 212
 213 /*
 214  * Send a list of DATA_BLOBs
 215  *
 216  * Example:  ctdb_packet_send(ctx, 2, data_blob_const(&size, sizeof(size)),
 217  *                       data_blob_const(buf, size));
 218  */
 219 NTSTATUS ctdb_packet_send(struct ctdb_packet_context *ctx, int num_blobs, ...)
 220 {
 221         va_list ap;
 222         int i;
 223         size_t len;
 224         uint8 *out;
 225
 226         len = ctx->out.length;
 227
 228         va_start(ap, num_blobs);
 229         for (i=0; i<num_blobs; i++) {
 230                 size_t tmp;
 231                 DATA_BLOB blob = va_arg(ap, DATA_BLOB);
 232
 233                 tmp = len + blob.length;
 234                 if (tmp < len) {
 235                         DEBUG(0, ("integer overflow\n"));
 236                         va_end(ap);
 237                         return NT_STATUS_NO_MEMORY;
 238                 }
 239                 len = tmp;
 240         }
 241         va_end(ap);
 242
 243         if (len == 0) {
 244                 return NT_STATUS_OK;
 245         }
 246
 247         if (!(out = talloc_realloc(ctx, ctx->out.data, uint8, len))) {
 248                 DEBUG(0, ("talloc failed\n"));
 249                 return NT_STATUS_NO_MEMORY;
 250         }
 251
 252         ctx->out.data = out;
 253
 254         va_start(ap, num_blobs);
 255         for (i=0; i<num_blobs; i++) {
 256                 DATA_BLOB blob = va_arg(ap, DATA_BLOB);
 257
 258                 memcpy(ctx->out.data+ctx->out.length, blob.data, blob.length);
 259                 ctx->out.length += blob.length;
 260         }
 261         va_end(ap);
 262
 263         SMB_ASSERT(ctx->out.length == len);
 264         return NT_STATUS_OK;
 265 }
 266
 267 /*
 268  * Get the ctdb_packet context's file descriptor
 269  */
 270 int ctdb_packet_get_fd(struct ctdb_packet_context *ctx)
 271 {
 272         return ctx->fd;
 273 }