1 /*
2  *
3  * adding/removing headers or any other data chunk from a message
4  *
5  * Copyright (C) 2001-2003 FhG Fokus
6  *
7  * This file is part of Kamailio, a free SIP server.
8  *
9  * Kamailio is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License as published by
11  * the Free Software Foundation; either version 2 of the License, or
12  * (at your option) any later version
13  *
14  * Kamailio is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17  * GNU General Public License for more details.
18  *
19  * You should have received a copy of the GNU General Public License
20  * along with this program; if not, write to the Free Software
21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
22  */
23 /*!
24 * \file
25 * \brief Kamailio core :: Adding/removing headers or any other data chunk from a message
26 * \ingroup core
27 * \author jiri, andrei, janakj
28 * Module: \ref core
29 */
30 
31 #ifndef lump_struct_h
32 #define lump_struct_h
33 
34 #include "./parser/hf.h"
35 
36 
37 enum lump_op { LUMP_NOP=0, LUMP_DEL, LUMP_ADD, LUMP_ADD_SUBST, LUMP_ADD_OPT };
38 
39 enum lump_subst{ SUBST_NOP=0,                  /* do nothing */
40 			SUBST_RCV_IP,     SUBST_SND_IP,    /* add ip address */
41 			SUBST_RCV_PORT,   SUBST_SND_PORT,  /* add port no */
42 			SUBST_RCV_PROTO,  SUBST_SND_PROTO, /* add protocol(udp,tcp,tls)*/
43 			SUBST_RCV_ALL,    SUBST_SND_ALL,   /* ip:port;transport=proto */
44 			SUBST_RCV_ALL_EX, SUBST_SND_ALL_EX /* ip:port;transport=proto;sn=xyz */
45 		};
46 				/* Where:
47 				 * SND = sending, e.g the src ip of the outgoing message
48 				 * RCV = received e.g the dst ip of the original incoming msg,
49 				 *  or the ip of the ser socket on which the msg was received
50 				 * For SUBST_{RCV,SND}_ALL, :port is added only if port!=5060
51 				 * and transport=proto only if proto!=udp
52 				 */
53 
54 enum lump_conditions {	COND_FALSE,         /* always false */
55 						COND_TRUE,          /* always true */
56 						COND_IF_DIFF_REALMS,/* true if RCV realm != SND realm */
57 						COND_IF_DIFF_AF,    /* true if RCV af != SND af */
58 						COND_IF_DIFF_PROTO, /* true if RCV proto != SND proto */
59 						COND_IF_DIFF_PORT,  /* true if RCV port != SND port */
60 						COND_IF_DIFF_IP,    /* true if RCV ip != SND ip */
61 						COND_IF_RAND        /* 50-50 random prob.of being true*/
62 						};
63 						/* Where:
64 						 * REALM= ip_addr:port:proto
65 						 * af   = address family (ipv4 or ipv6)
66 						 * proto = protocol (tcp, udp, tls)
67 						*/
68 
69 enum lump_flag { LUMPFLAG_NONE=0,  /* */
70 	LUMPFLAG_DUPED=1,              /* lump struct duplicated in pkg, with value
71 									* pointing to initial lump structure
72 									* - e.g., used for branch_route execution */
73 	LUMPFLAG_SHMEM=2,              /* lump stored in shared memory (e.g., tm) */
74 	LUMPFLAG_BRANCH=4,             /* not in use ?!? */
75 	LUMPFLAG_COND_TRUE=8           /* conditional lump processing */
76 };
77 
78 #define LUMP_SET_COND_TRUE(_lump)	 (_lump)->flags |= LUMPFLAG_COND_TRUE
79 #define LUMP_IS_COND_TRUE(_lump)	 ((_lump)->flags & LUMPFLAG_COND_TRUE)
80 
81 typedef struct lump{
82 	enum _hdr_types_t type; /* HDR_VIA_T, HDR_OTHER_T (0), ... */
83 	enum lump_op op;   /* DEL, ADD, NOP, UNSPEC(=0) */
84 
85 	union{
86 		int offset; /* used for DEL, MODIFY */
87 		enum lump_subst subst; /*what to subst: ip addr, port, proto*/
88 		enum lump_conditions cond; /* condition for LUMP_ADD_OPT */
89 		char * value; /* used for ADD */
90 	}u;
91 	int len; /* length of this header field */
92 
93 
94 	struct lump* before; /* list of headers to be inserted in front of the
95 								current one */
96 	struct lump* after;    /* list of headers to be inserted immediately after
97 							* the current one */
98 
99 	struct lump* next;
100 
101 	enum lump_flag flags; /* additional hints for use from TM's shmem */
102 } sr_lump_t;
103 
104 
105 /*
106  * hdrs must be kept sorted after their offset (DEL, NOP, UNSPEC)
107  * and/or their position (ADD). E.g.:
108  *  - to delete header Z insert it in to the list according to its offset
109  *   and with op=DELETE
110  * - if you want to add a new header X after a  header Y, insert Y in the list
111  *   with op NOP and after it X (op ADD).
112  * - if you want X before Y, insert X in Y's before list.
113  * - if you want X to be the first header just put it first in hdr_lst.
114  *  -if you want to replace Y with X, insert Y with op=DELETE and then X with
115  *  op=ADD.
116  * before and after must contain only ADD ops!
117  *
118  * Difference between "after" & "next" when Adding:
119  * "after" forces the new header immediately after the current one while
120  * "next" means another header can be inserted between them.
121  *
122  */
123 
124 /* frees the content of a lump struct */
125 void free_lump(struct lump* l);
126 /* frees an entire lump list, recursively */
127 void free_lump_list(struct lump* lump_list);
128 /* count applied lumps in a list having a specific type */
129 unsigned int count_applied_lumps(struct lump *ll, int type);
130 #endif
131