Imported Upstream version 1.1.1+rev1207upstream/1.1.1+rev1207

1 files changed, 173 insertions, 0 deletions

diff --git a/lib/libucsi/section_buf.c b/lib/libucsi/section_buf.c
new file mode 100644
index 0000000..35d465e
--- /dev/null
+++ b/lib/libucsi/section_buf.c
@@ -0,0 +1,173 @@
+/*
+ * section and descriptor parser
+ *
+ * Copyright (C) 2005 Andrew de Quincey (adq_dvb@lidskialf.net)
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
+ */
+
+#include <errno.h>
+#include <string.h>
+#include "section_buf.h"
+
+#define SECTION_HDR_SIZE 3
+#define SECTION_PAD 0xff
+
+int section_buf_init(struct section_buf *section, int max)
+{
+	if (max < SECTION_HDR_SIZE)
+		return -EINVAL;
+
+	memset(section, 0, sizeof(struct section_buf));
+	section->max = max; /* max size of data */
+	section->len = SECTION_HDR_SIZE;
+	section->wait_pdu = 1;
+
+	return 0;
+}
+
+int section_buf_add(struct section_buf *section, uint8_t* frag, int len, int *section_status)
+{
+	int copy;
+	int used = 0;
+	uint8_t *data;
+	uint8_t *pos = (uint8_t*) section + sizeof(struct section_buf) + section->count;
+
+	/* have we finished? */
+	if (section->header && (section->len == section->count)) {
+		*section_status = 1;
+		return 0;
+	}
+
+	/* skip over section padding bytes */
+	*section_status = 0;
+	if (section->count == 0) {
+		while(len && (*frag == SECTION_PAD)) {
+			frag++;
+			len--;
+			used++;
+		}
+
+		if (len == 0)
+			return used;
+	}
+
+	/* grab the header to get the section length */
+	if (!section->header) {
+		/* copy the header frag */
+		copy = SECTION_HDR_SIZE - section->count;
+		if (copy > len)
+			copy = len;
+		memcpy(pos, frag, copy);
+		section->count += copy;
+		pos += copy;
+		frag += copy;
+		used += copy;
+		len -= copy;
+
+		/* we need 3 bytes for the section header */
+		if (section->count != SECTION_HDR_SIZE)
+			return used;
+
+		/* work out the length & check it isn't too big */
+		data = (uint8_t*) section + sizeof(struct section_buf);
+		section->len = SECTION_HDR_SIZE + (((data[1] & 0x0f) << 8) | data[2]);
+		if (section->len > section->max) {
+			*section_status = -ERANGE;
+			return len + used;
+		}
+
+		/* update fields */
+		section->header = 1;
+	}
+
+	/* accumulate frag */
+	copy = section->len - section->count;
+	if (copy > len)
+		copy = len;
+	memcpy(pos, frag, copy);
+	section->count += copy;
+	used += copy;
+
+	/* have we finished? */
+	if (section->header && (section->len == section->count))
+		*section_status = 1;
+
+	/* return number of bytes used */
+	return used;
+}
+
+int section_buf_add_transport_payload(struct section_buf *section,
+				      uint8_t* payload, int len,
+				      int pdu_start, int *section_status)
+{
+	int used = 0;
+	int tmp;
+
+	/* have we finished? */
+	if (section->header && (section->len == section->count)) {
+		*section_status = 1;
+		return 0;
+	}
+
+	/* don't bother if we're waiting for a PDU */
+	*section_status = 0;
+	if (section->wait_pdu && (!pdu_start))
+		return len;
+
+	/* if we're at a PDU start, we need extra handling for the extra first
+	 * byte giving the offset to the start of the next section. */
+	if (pdu_start) {
+		/* we have received a pdu */
+		section->wait_pdu = 0;
+
+		/* work out the offset to the _next_ payload */
+		int offset = payload[0];
+		if ((offset+1) > len) {
+			section->wait_pdu = 1;
+			*section_status = -EINVAL;
+			return len;
+		}
+
+		/* accumulate the end if we need to */
+		if (section->count != 0) {
+			/* add the final fragment. */
+			tmp = section_buf_add(section, payload + 1, offset, section_status);
+
+			/* the stream said this was the final fragment
+			 * (PDU START bit) - check that it really was! */
+			if ((tmp != offset) || section_buf_remaining(section) || (*section_status != 1)) {
+				*section_status = -ERANGE;
+				section->wait_pdu = 1;
+				return 1 + tmp;
+			}
+
+			/* it is complete - return the number of bytes we used */
+			return 1 + tmp;
+		}
+
+		/* otherwise, we skip the end of the previous section, and
+		 * start accumulating the new data. */
+		used = 1 + offset;
+	}
+
+	/* ok, just accumulate the data as normal */
+	tmp = section_buf_add(section, payload+used, len - used, section_status);
+	if (*section_status < 0) {
+		section->wait_pdu = 1;
+	}
+
+	return used + tmp;
+}