浏览代码

get_body_part() function is introduced, that returns
a specific part of the message body, for example application/sdp.
The result can be the whole body, or a part of it
in case of multipart/somehing Content-Type.

Miklos Tirpak 17 年之前
父节点
当前提交
0580adb02d
共有 3 个文件被更改,包括 336 次插入0 次删除
  1. 291 0
      parser/parse_body.c
  2. 40 0
      parser/parse_body.h
  3. 5 0
      parser/parse_content.h

+ 291 - 0
parser/parse_body.c

@@ -0,0 +1,291 @@
+/*
+ * $Id$
+ *
+ * Copyright (C) 2008 iptelorg GmbH
+ *
+ * This file is part of ser, a free SIP server.
+ *
+ * ser 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 of the License, or
+ * (at your option) any later version
+ *
+ * For a license to use the ser software under conditions
+ * other than those described here, or to purchase support for this
+ * software, please contact iptel.org by e-mail at the following addresses:
+ *    [email protected]
+ *
+ * ser 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 this program; if not, write to the Free Software 
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ * History:
+ * --------
+ *  2008-05-22  Initial version, get_body_part() is introduced (Miklos)
+ */
+
+#include "../trim.h"
+#include "parser_f.h"
+#include "parse_content.h"
+#include "parse_param.h"
+#include "keys.h"
+#include "parse_body.h"
+
+/* returns the value of boundary parameter from the Contect-Type HF */
+static inline int get_boundary_param(struct sip_msg *msg, str *boundary)
+{
+	str	s;
+	char	*c;
+	param_t	*p, *list;
+
+#define is_boundary(c) \
+	(((c)[0] == 'b' || (c)[0] == 'B') && \
+	((c)[1] == 'o' || (c)[1] == 'O') && \
+	((c)[2] == 'u' || (c)[2] == 'U') && \
+	((c)[3] == 'n' || (c)[3] == 'N') && \
+	((c)[4] == 'd' || (c)[4] == 'D') && \
+	((c)[5] == 'a' || (c)[5] == 'A') && \
+	((c)[6] == 'r' || (c)[6] == 'R') && \
+	((c)[7] == 'y' || (c)[7] == 'Y'))
+
+#define boundary_param_len (sizeof("boundary")-1)
+
+	/* get the pointer to the beginning of the parameter list */
+	s.s = msg->content_type->body.s;
+	s.len = msg->content_type->body.len;
+	c = find_not_quoted(&s, ';');
+	if (!c)
+		return -1;
+	c++;
+	s.len = s.len - (c - s.s);
+	s.s = c;
+	trim_leading(&s);
+
+	if (s.len <= 0)
+		return -1;
+
+	/* parse the parameter list, and search for boundary */
+	if (parse_params(&s, CLASS_ANY, NULL, &list)<0)
+		return -1;
+
+	boundary->s = NULL;
+	for (p = list; p; p = p->next)
+		if ((p->name.len == boundary_param_len) &&
+			is_boundary(p->name.s)
+		) {
+			boundary->s = p->body.s;
+			boundary->len = p->body.len;
+			break;
+		}
+	free_params(list);
+	if (!boundary->s || !boundary->len)
+		return -1;
+
+	DBG("boundary is \"%.*s\"\n",
+		boundary->len, boundary->s);
+	return 0;
+}
+
+/* search the next boundary in the buffer */
+static inline char *search_boundary(char *buf, char *buf_end, str *boundary)
+{
+	char *c;
+
+	c = buf;
+	while (c + 2 /* -- */ + boundary->len < buf_end) {
+		if ((*c == '-') && (*(c+1) == '-') &&
+			(memcmp(c+2, boundary->s, boundary->len) == 0)
+		)
+			return c; /* boundary found */
+
+		/* go to the next line */
+		while ((c < buf_end) && (*c != '\n')) c++;
+		c++;
+	}
+	return NULL;
+}
+
+/* extract the body of a part from a multipart SIP msg body */
+inline static char *get_multipart_body(char *buf,
+					char *buf_end,
+					str *boundary,
+					int *len)
+{
+	char *beg, *end;
+
+	if (buf >= buf_end)
+		goto error;
+
+	beg = buf;
+	while ((*beg != '\r') && (*beg != '\n')) {
+		while ((beg < buf_end) && (*beg != '\n'))
+			beg++;
+		beg++;
+		if (beg >= buf_end)
+			goto error;
+	}
+	/* CRLF delimeter found, the body begins right after it */
+	while ((beg < buf_end) && (*beg != '\n'))
+		beg++;
+	beg++;
+	if (beg >= buf_end)
+		goto error;
+
+	if (!(end = search_boundary(beg, buf_end, boundary)))
+		goto error;
+
+	/* CRLF preceding the boundary belongs to the boundary
+	and not to the body */
+	if (*(end-1) == '\n') end--;
+	if (*(end-1) == '\r') end--;
+
+	if (end < beg)
+		goto error;
+
+	*len = end-beg;
+	return beg;
+error:
+	ERR("failed to extract the body from the multipart mime type\n");
+	return NULL;
+}
+
+
+/* macros from parse_hname2.c */
+#define READ(val) \
+(*(val + 0) + (*(val + 1) << 8) + (*(val + 2) << 16) + (*(val + 3) << 24))
+
+#define LOWER_DWORD(d) ((d) | 0x20202020)
+
+/* Returns the pointer within the msg body to the given type/subtype,
+ * and sets the length of the body part.
+ * The result can be the whole msg body, or a part of a multipart body.
+ */
+char *get_body_part(	struct sip_msg *msg,
+			unsigned short type, unsigned short subtype,
+			int *len)
+{
+	int	mime;
+	unsigned int	umime;
+	char	*c, *c2, *buf_end;
+	str	boundary;
+
+#define content_type_len \
+	(sizeof("Content-Type") - 1)
+
+	if ((mime = parse_content_type_hdr(msg)) <= 0)
+		return NULL;
+
+	if (mime == ((type<<16)|subtype)) {
+		/* content-type is type/subtype */
+		c = get_body(msg);
+		if (c)
+			*len = msg->buf+msg->len - c;
+		return c;
+
+	} else if ((mime>>16) == TYPE_MULTIPART) {
+		/* type is multipart/something, search for type/subtype part */
+
+		if (get_boundary_param(msg, &boundary)) {
+			ERR("failed to get boundary parameter\n");
+			return NULL;
+		}
+		if (!(c = get_body(msg)))
+			return NULL;
+		buf_end = msg->buf+msg->len;
+
+		/* check all the body parts delimated by the boundary value,
+		and search for the Content-Type HF with the given 
+		type/subtype */
+next_part:
+		while ((c = search_boundary(c, buf_end, &boundary))) {
+			/* skip boundary */
+			c += 2 + boundary.len;
+
+			if ((c+2 > buf_end) ||
+				((*c == '-') && (*(c+1) == '-'))
+			)
+				/* end boundary, no more body part
+				will follow */
+				return NULL;
+
+			/* go to the next line */
+			while ((c < buf_end) && (*c != '\n')) c++;
+			c++;
+			if (c >= buf_end)
+				return NULL;
+
+			/* try to find the content-type header */
+			while ((*c != '\r') && (*c != '\n')) {
+				if (c + content_type_len >= buf_end)
+					return NULL;
+
+				if ((LOWER_DWORD(READ(c)) == _cont_) &&
+					(LOWER_DWORD(READ(c+4)) == _ent__) &&
+					(LOWER_DWORD(READ(c+8)) == _type_)
+				) {
+					/* Content-Type HF found */
+					c += content_type_len;
+					while ((c < buf_end) &&
+						((*c == ' ') || (*c == '\t'))
+					)
+						c++;
+
+					if (c + 1 /* : */ >= buf_end)
+						return NULL;
+
+					if (*c != ':')
+						/* not realy a Content-Type HF */
+						goto next_hf;
+					c++;
+
+					/* search the end of the header body,
+					decode_mime_type() needs it */
+					c2 = c;
+					while (((c2 < buf_end) && (*c2 != '\n')) ||
+						((c2+1 < buf_end) && (*c2 == '\n') &&
+							((*(c2+1) == ' ') || (*(c2+1) == '\t')))
+					)
+						c2++;
+
+					if (c2 >= buf_end)
+						return NULL;
+					if (*(c2-1) == '\r') c2--;
+
+					if (!decode_mime_type(c, c2 , &umime)) {
+						ERR("failed to decode the mime type\n");
+						return NULL;
+					}
+
+					/* c2 points to the CRLF at the end of the line,
+					move the pointer to the beginning of the next line */
+					c = c2;
+					if ((c < buf_end) && (*c == '\r')) c++;
+					if ((c < buf_end) && (*c == '\n')) c++;
+
+					if (umime != ((type<<16)|subtype)) {
+						/* this is not the part we are looking for */
+						goto next_part;
+					}
+
+					/* the requested type/subtype is found! */
+					return get_multipart_body(c,
+							buf_end,
+							&boundary,
+							len);
+				}
+next_hf:
+				/* go to the next line */
+				while ((c < buf_end) && (*c != '\n')) c++;
+				c++;
+			}
+			/* CRLF delimeter reached,
+			no Content-Type HF was found */
+		}
+	}
+	return NULL;
+}

+ 40 - 0
parser/parse_body.h

@@ -0,0 +1,40 @@
+/*
+ * $Id$
+ *
+ * Copyright (C) 2008 iptelorg GmbH
+ *
+ * This file is part of ser, a free SIP server.
+ *
+ * ser 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 of the License, or
+ * (at your option) any later version
+ *
+ * For a license to use the ser software under conditions
+ * other than those described here, or to purchase support for this
+ * software, please contact iptel.org by e-mail at the following addresses:
+ *    [email protected]
+ *
+ * ser 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 this program; if not, write to the Free Software 
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ */
+
+#ifndef PARSE_BODY_H
+#define PARSE_BODY_H
+
+/* Returns the pointer within the msg body to the given type/subtype,
+ * and sets the length.
+ * The result can be the whole msg body, or a part of a multipart body.
+ */
+char *get_body_part(	struct sip_msg *msg,
+			unsigned short type, unsigned short subtype,
+			int *len);
+
+#endif /* PARSE_BODY_H */

+ 5 - 0
parser/parse_content.h

@@ -120,4 +120,9 @@ int parse_accept_hdr( struct sip_msg *msg );
  */
 char* parse_content_length( char* buffer, char* end, int* len);
 
+/*
+ * Sets the mime type from the body of a Content-Type header
+ */
+char* decode_mime_type(char *start, char *end, unsigned int *mime_type);
+
 #endif