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-rw-r--r--src/util/server_mst.c321
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diff --git a/src/util/server_mst.c b/src/util/server_mst.c
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+/*
+ This file is part of GNUnet.
+ (C) 2010 Christian Grothoff (and other contributing authors)
+
+ GNUnet is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published
+ by the Free Software Foundation; either version 2, or (at your
+ option) any later version.
+
+ GNUnet is distributed in the hope that it will be useful, but
+ WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with GNUnet; see the file COPYING. If not, write to the
+ Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ Boston, MA 02111-1307, USA.
+*/
+
+/**
+ * @file util/server_mst.c
+ * @brief convenience functions for handling inbound message buffers
+ * @author Christian Grothoff
+ */
+
+#include "platform.h"
+#include "gnunet_common.h"
+#include "gnunet_connection_lib.h"
+#include "gnunet_scheduler_lib.h"
+#include "gnunet_server_lib.h"
+#include "gnunet_time_lib.h"
+
+#define DEBUG_SERVER_MST GNUNET_EXTRA_LOGGING
+
+#if HAVE_UNALIGNED_64_ACCESS
+#define ALIGN_FACTOR 4
+#else
+#define ALIGN_FACTOR 8
+#endif
+
+#define LOG(kind,...) GNUNET_log_from (kind, "util", __VA_ARGS__)
+
+
+/**
+ * Handle to a message stream tokenizer.
+ */
+struct GNUNET_SERVER_MessageStreamTokenizer
+{
+
+ /**
+ * Function to call on completed messages.
+ */
+ GNUNET_SERVER_MessageTokenizerCallback cb;
+
+ /**
+ * Closure for cb.
+ */
+ void *cb_cls;
+
+ /**
+ * Size of the buffer (starting at 'hdr').
+ */
+ size_t curr_buf;
+
+ /**
+ * How many bytes in buffer have we already processed?
+ */
+ size_t off;
+
+ /**
+ * How many bytes in buffer are valid right now?
+ */
+ size_t pos;
+
+ /**
+ * Beginning of the buffer. Typed like this to force alignment.
+ */
+ struct GNUNET_MessageHeader *hdr;
+
+};
+
+
+
+/**
+ * Create a message stream tokenizer.
+ *
+ * @param cb function to call on completed messages
+ * @param cb_cls closure for cb
+ * @return handle to tokenizer
+ */
+struct GNUNET_SERVER_MessageStreamTokenizer *
+GNUNET_SERVER_mst_create (GNUNET_SERVER_MessageTokenizerCallback cb,
+ void *cb_cls)
+{
+ struct GNUNET_SERVER_MessageStreamTokenizer *ret;
+
+ ret = GNUNET_malloc (sizeof (struct GNUNET_SERVER_MessageStreamTokenizer));
+ ret->hdr = GNUNET_malloc (GNUNET_SERVER_MIN_BUFFER_SIZE);
+ ret->curr_buf = GNUNET_SERVER_MIN_BUFFER_SIZE;
+ ret->cb = cb;
+ ret->cb_cls = cb_cls;
+ return ret;
+}
+
+
+/**
+ * Add incoming data to the receive buffer and call the
+ * callback for all complete messages.
+ *
+ * @param mst tokenizer to use
+ * @param client_identity ID of client for which this is a buffer
+ * @param buf input data to add
+ * @param size number of bytes in buf
+ * @param purge should any excess bytes in the buffer be discarded
+ * (i.e. for packet-based services like UDP)
+ * @param one_shot only call callback once, keep rest of message in buffer
+ * @return GNUNET_OK if we are done processing (need more data)
+ * GNUNET_NO if one_shot was set and we have another message ready
+ * GNUNET_SYSERR if the data stream is corrupt
+ */
+int
+GNUNET_SERVER_mst_receive (struct GNUNET_SERVER_MessageStreamTokenizer *mst,
+ void *client_identity, const char *buf, size_t size,
+ int purge, int one_shot)
+{
+ const struct GNUNET_MessageHeader *hdr;
+ size_t delta;
+ uint16_t want;
+ char *ibuf;
+ int need_align;
+ unsigned long offset;
+ int ret;
+
+ GNUNET_assert (mst->off <= mst->pos);
+ GNUNET_assert (mst->pos <= mst->curr_buf);
+#if DEBUG_SERVER_MST
+ LOG (GNUNET_ERROR_TYPE_DEBUG,
+ "Server-mst receives %u bytes with %u bytes already in private buffer\n",
+ (unsigned int) size, (unsigned int) (mst->pos - mst->off));
+#endif
+ ret = GNUNET_OK;
+ ibuf = (char *) mst->hdr;
+ while (mst->pos > 0)
+ {
+do_align:
+ GNUNET_assert (mst->pos >= mst->off);
+ if ((mst->curr_buf - mst->off < sizeof (struct GNUNET_MessageHeader)) ||
+ (0 != (mst->off % ALIGN_FACTOR)))
+ {
+ /* need to align or need more space */
+ mst->pos -= mst->off;
+ memmove (ibuf, &ibuf[mst->off], mst->pos);
+ mst->off = 0;
+ }
+ if (mst->pos - mst->off < sizeof (struct GNUNET_MessageHeader))
+ {
+ delta =
+ GNUNET_MIN (sizeof (struct GNUNET_MessageHeader) -
+ (mst->pos - mst->off), size);
+ memcpy (&ibuf[mst->pos], buf, delta);
+ mst->pos += delta;
+ buf += delta;
+ size -= delta;
+ }
+ if (mst->pos - mst->off < sizeof (struct GNUNET_MessageHeader))
+ {
+ if (purge)
+ {
+ mst->off = 0;
+ mst->pos = 0;
+ }
+ return GNUNET_OK;
+ }
+ hdr = (const struct GNUNET_MessageHeader *) &ibuf[mst->off];
+ want = ntohs (hdr->size);
+ if (want < sizeof (struct GNUNET_MessageHeader))
+ {
+ GNUNET_break_op (0);
+ return GNUNET_SYSERR;
+ }
+ if ( (mst->curr_buf - mst->off < want) &&
+ (mst->off > 0) )
+ {
+ /* can get more space by moving */
+ mst->pos -= mst->off;
+ memmove (ibuf, &ibuf[mst->off], mst->pos);
+ mst->off = 0;
+ }
+ if (mst->curr_buf < want)
+ {
+ /* need to get more space by growing buffer */
+ GNUNET_assert (0 == mst->off);
+ mst->hdr = GNUNET_realloc (mst->hdr, want);
+ ibuf = (char *) mst->hdr;
+ mst->curr_buf = want;
+ }
+ hdr = (const struct GNUNET_MessageHeader *) &ibuf[mst->off];
+ if (mst->pos - mst->off < want)
+ {
+ delta = GNUNET_MIN (want - (mst->pos - mst->off), size);
+ GNUNET_assert (mst->pos + delta <= mst->curr_buf);
+ memcpy (&ibuf[mst->pos], buf, delta);
+ mst->pos += delta;
+ buf += delta;
+ size -= delta;
+ }
+ if (mst->pos - mst->off < want)
+ {
+ if (purge)
+ {
+ mst->off = 0;
+ mst->pos = 0;
+ }
+ return GNUNET_OK;
+ }
+ if (one_shot == GNUNET_SYSERR)
+ {
+ /* cannot call callback again, but return value saying that
+ * we have another full message in the buffer */
+ ret = GNUNET_NO;
+ goto copy;
+ }
+ if (one_shot == GNUNET_YES)
+ one_shot = GNUNET_SYSERR;
+ mst->off += want;
+ mst->cb (mst->cb_cls, client_identity, hdr);
+ if (mst->off == mst->pos)
+ {
+ /* reset to beginning of buffer, it's free right now! */
+ mst->off = 0;
+ mst->pos = 0;
+ }
+ }
+ GNUNET_assert (0 == mst->pos);
+ while (size > 0)
+ {
+#if DEBUG_SERVER_MST
+ LOG (GNUNET_ERROR_TYPE_DEBUG,
+ "Server-mst has %u bytes left in inbound buffer\n",
+ (unsigned int) size);
+#endif
+ if (size < sizeof (struct GNUNET_MessageHeader))
+ break;
+ offset = (unsigned long) buf;
+ need_align = (0 != (offset % ALIGN_FACTOR)) ? GNUNET_YES : GNUNET_NO;
+ if (GNUNET_NO == need_align)
+ {
+ /* can try to do zero-copy and process directly from original buffer */
+ hdr = (const struct GNUNET_MessageHeader *) buf;
+ want = ntohs (hdr->size);
+ if (want < sizeof (struct GNUNET_MessageHeader))
+ {
+ GNUNET_break_op (0);
+ mst->off = 0;
+ return GNUNET_SYSERR;
+ }
+ if (size < want)
+ break; /* or not: buffer incomplete, so copy to private buffer... */
+ if (one_shot == GNUNET_SYSERR)
+ {
+ /* cannot call callback again, but return value saying that
+ * we have another full message in the buffer */
+ ret = GNUNET_NO;
+ goto copy;
+ }
+ if (one_shot == GNUNET_YES)
+ one_shot = GNUNET_SYSERR;
+ mst->cb (mst->cb_cls, client_identity, hdr);
+ buf += want;
+ size -= want;
+ }
+ else
+ {
+ /* need to copy to private buffer to align;
+ * yes, we go a bit more spagetti than usual here */
+ goto do_align;
+ }
+ }
+copy:
+ if ((size > 0) && (!purge))
+ {
+ if (size + mst->pos > mst->curr_buf)
+ {
+ mst->hdr = GNUNET_realloc (mst->hdr, size + mst->pos);
+ ibuf = (char *) mst->hdr;
+ mst->curr_buf = size + mst->pos;
+ }
+ GNUNET_assert (size + mst->pos <= mst->curr_buf);
+ memcpy (&ibuf[mst->pos], buf, size);
+ mst->pos += size;
+ }
+ if (purge)
+ {
+ mst->off = 0;
+ mst->pos = 0;
+ }
+#if DEBUG_SERVER_MST
+ LOG (GNUNET_ERROR_TYPE_DEBUG,
+ "Server-mst leaves %u bytes in private buffer\n",
+ (unsigned int) (mst->pos - mst->off));
+#endif
+ return ret;
+}
+
+
+/**
+ * Destroys a tokenizer.
+ *
+ * @param mst tokenizer to destroy
+ */
+void
+GNUNET_SERVER_mst_destroy (struct GNUNET_SERVER_MessageStreamTokenizer *mst)
+{
+ GNUNET_free (mst->hdr);
+ GNUNET_free (mst);
+}
+
+
+
+/* end of server_mst.c */
generated by cgit v1.2.3-18-g5258 (git 2.32.0) at 2024-11-21 13:38:13 +0000