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 "system/select.h"
  24 #include "ctdb_packet.h"
  25
  26 struct ctdb_packet_context {
  27         int fd;
  28         DATA_BLOB in, out;
  29 };
  30
  31 /*
  32  * Close the underlying fd
  33  */
  34 static int ctdb_packet_context_destructor(struct ctdb_packet_context *ctx)
  35 {
  36         return close(ctx->fd);
  37 }
  38
  39 /*
  40  * Initialize a ctdb_packet context. The fd is given to the ctdb_packet context, meaning
  41  * that it is automatically closed when the ctdb_packet context is freed.
  42  */
  43 struct ctdb_packet_context *ctdb_packet_init(TALLOC_CTX *mem_ctx, int fd)
  44 {
  45         struct ctdb_packet_context *result;
  46
  47         if (!(result = talloc_zero(mem_ctx, struct ctdb_packet_context))) {
  48                 return NULL;
  49         }
  50
  51         result->fd = fd;
  52         talloc_set_destructor(result, ctdb_packet_context_destructor);
  53         return result;
  54 }
  55
  56 /*
  57  * Pull data from the fd
  58  */
  59 NTSTATUS ctdb_packet_fd_read(struct ctdb_packet_context *ctx)
  60 {
  61         int res, available;
  62         size_t new_size;
  63         uint8 *in;
  64
  65         res = ioctl(ctx->fd, FIONREAD, &available);
  66
  67         if (res == -1) {
  68                 DEBUG(10, ("ioctl(FIONREAD) failed: %s\n", strerror(errno)));
  69                 return map_nt_error_from_unix(errno);
  70         }
  71
  72         SMB_ASSERT(available >= 0);
  73
  74         if (available == 0) {
  75                 return NT_STATUS_END_OF_FILE;
  76         }
  77
  78         new_size = ctx->in.length + available;
  79
  80         if (new_size < ctx->in.length) {
  81                 DEBUG(0, ("integer wrap\n"));
  82                 return NT_STATUS_NO_MEMORY;
  83         }
  84
  85         if (!(in = talloc_realloc(ctx, ctx->in.data, uint8, new_size))) {
  86                 DEBUG(10, ("talloc failed\n"));
  87                 return NT_STATUS_NO_MEMORY;
  88         }
  89
  90         ctx->in.data = in;
  91
  92         res = recv(ctx->fd, in + ctx->in.length, available, 0);
  93
  94         if (res < 0) {
  95                 DEBUG(10, ("recv failed: %s\n", strerror(errno)));
  96                 return map_nt_error_from_unix(errno);
  97         }
  98
  99         if (res == 0) {
 100                 return NT_STATUS_END_OF_FILE;
 101         }
 102
 103         ctx->in.length += res;
 104
 105         return NT_STATUS_OK;
 106 }
 107
 108 NTSTATUS ctdb_packet_fd_read_sync_timeout(struct ctdb_packet_context *ctx, int timeout)
 109 {
 110         int res, revents;
 111
 112         res = poll_one_fd(ctx->fd, POLLIN|POLLHUP, timeout, &revents);
 113         if (res == 0) {
 114                 DEBUG(10, ("poll timed out\n"));
 115                 return NT_STATUS_IO_TIMEOUT;
 116         }
 117
 118         if (res == -1) {
 119                 DEBUG(10, ("poll returned %s\n", strerror(errno)));
 120                 return map_nt_error_from_unix(errno);
 121         }
 122         if ((revents & (POLLIN|POLLHUP|POLLERR)) == 0) {
 123                 DEBUG(10, ("socket not readable\n"));
 124                 return NT_STATUS_IO_TIMEOUT;
 125         }
 126
 127         return ctdb_packet_fd_read(ctx);
 128 }
 129
 130 bool ctdb_packet_handler(struct ctdb_packet_context *ctx,
 131                     bool (*full_req)(const uint8_t *buf,
 132                                      size_t available,
 133                                      size_t *length,
 134                                      void *priv),
 135                     NTSTATUS (*callback)(uint8_t *buf, size_t length,
 136                                          void *priv),
 137                     void *priv, NTSTATUS *status)
 138 {
 139         size_t length;
 140         uint8_t *buf;
 141
 142         if (!full_req(ctx->in.data, ctx->in.length, &length, priv)) {
 143                 return False;
 144         }
 145
 146         if (length > ctx->in.length) {
 147                 *status = NT_STATUS_INTERNAL_ERROR;
 148                 return true;
 149         }
 150
 151         if (length == ctx->in.length) {
 152                 buf = ctx->in.data;
 153                 ctx->in.data = NULL;
 154                 ctx->in.length = 0;
 155         } else {
 156                 buf = (uint8_t *)talloc_memdup(ctx, ctx->in.data, length);
 157                 if (buf == NULL) {
 158                         *status = NT_STATUS_NO_MEMORY;
 159                         return true;
 160                 }
 161
 162                 memmove(ctx->in.data, ctx->in.data + length,
 163                         ctx->in.length - length);
 164                 ctx->in.length -= length;
 165         }
 166
 167         *status = callback(buf, length, priv);
 168         return True;
 169 }
 170
 171 /*
 172  * How many bytes of outgoing data do we have pending?
 173  */
 174 size_t ctdb_packet_outgoing_bytes(struct ctdb_packet_context *ctx)
 175 {
 176         return ctx->out.length;
 177 }
 178
 179 /*
 180  * Push data to the fd
 181  */
 182 NTSTATUS ctdb_packet_fd_write(struct ctdb_packet_context *ctx)
 183 {
 184         ssize_t sent;
 185
 186         sent = send(ctx->fd, ctx->out.data, ctx->out.length, 0);
 187
 188         if (sent == -1) {
 189                 DEBUG(0, ("send failed: %s\n", strerror(errno)));
 190                 return map_nt_error_from_unix(errno);
 191         }
 192
 193         memmove(ctx->out.data, ctx->out.data + sent,
 194                 ctx->out.length - sent);
 195         ctx->out.length -= sent;
 196
 197         return NT_STATUS_OK;
 198 }
 199
 200 /*
 201  * Sync flush all outgoing bytes
 202  */
 203 NTSTATUS ctdb_packet_flush(struct ctdb_packet_context *ctx)
 204 {
 205         while (ctx->out.length != 0) {
 206                 NTSTATUS status = ctdb_packet_fd_write(ctx);
 207                 if (!NT_STATUS_IS_OK(status)) {
 208                         return status;
 209                 }
 210         }
 211         return NT_STATUS_OK;
 212 }
 213
 214 /*
 215  * Send a list of DATA_BLOBs
 216  *
 217  * Example:  ctdb_packet_send(ctx, 2, data_blob_const(&size, sizeof(size)),
 218  *                       data_blob_const(buf, size));
 219  */
 220 NTSTATUS ctdb_packet_send(struct ctdb_packet_context *ctx, int num_blobs, ...)
 221 {
 222         va_list ap;
 223         int i;
 224         size_t len;
 225         uint8 *out;
 226
 227         len = ctx->out.length;
 228
 229         va_start(ap, num_blobs);
 230         for (i=0; i<num_blobs; i++) {
 231                 size_t tmp;
 232                 DATA_BLOB blob = va_arg(ap, DATA_BLOB);
 233
 234                 tmp = len + blob.length;
 235                 if (tmp < len) {
 236                         DEBUG(0, ("integer overflow\n"));
 237                         va_end(ap);
 238                         return NT_STATUS_NO_MEMORY;
 239                 }
 240                 len = tmp;
 241         }
 242         va_end(ap);
 243
 244         if (len == 0) {
 245                 return NT_STATUS_OK;
 246         }
 247
 248         if (!(out = talloc_realloc(ctx, ctx->out.data, uint8, len))) {
 249                 DEBUG(0, ("talloc failed\n"));
 250                 return NT_STATUS_NO_MEMORY;
 251         }
 252
 253         ctx->out.data = out;
 254
 255         va_start(ap, num_blobs);
 256         for (i=0; i<num_blobs; i++) {
 257                 DATA_BLOB blob = va_arg(ap, DATA_BLOB);
 258
 259                 memcpy(ctx->out.data+ctx->out.length, blob.data, blob.length);
 260                 ctx->out.length += blob.length;
 261         }
 262         va_end(ap);
 263
 264         SMB_ASSERT(ctx->out.length == len);
 265         return NT_STATUS_OK;
 266 }
 267
 268 /*
 269  * Get the ctdb_packet context's file descriptor
 270  */
 271 int ctdb_packet_get_fd(struct ctdb_packet_context *ctx)
 272 {
 273         return ctx->fd;
 274 }