xref: /netbsd-src/external/ibm-public/postfix/dist/src/cleanup/cleanup_map1n.c (revision a5847cc334d9a7029f6352b847e9e8d71a0f9e0c)
1 /*	$NetBSD: cleanup_map1n.c,v 1.1.1.2 2011/03/02 19:32:09 tron Exp $	*/
2 
3 /*++
4 /* NAME
5 /*	cleanup_map1n 3
6 /* SUMMARY
7 /*	one-to-many address mapping
8 /* SYNOPSIS
9 /*	#include <cleanup.h>
10 /*
11 /*	ARGV	*cleanup_map1n_internal(state, addr, maps, propagate)
12 /*	CLEANUP_STATE *state;
13 /*	const char *addr;
14 /*	MAPS	*maps;
15 /*	int	propagate;
16 /* DESCRIPTION
17 /*	This module implements one-to-many table mapping via table lookup.
18 /*	Table lookups are done with quoted (externalized) address forms.
19 /*	The process is recursive. The recursion terminates when the
20 /*	left-hand side appears in its own expansion.
21 /*
22 /*	cleanup_map1n_internal() is the interface for addresses in
23 /*	internal (unquoted) form.
24 /* DIAGNOSTICS
25 /*	When the maximal expansion or recursion limit is reached,
26 /*	the alias is not expanded and the CLEANUP_STAT_DEFER error
27 /*	is raised with reason "4.6.0 Alias expansion error".
28 /*
29 /*	When table lookup fails, the alias is not expanded and the
30 /*	CLEANUP_STAT_WRITE error is raised with reason "4.6.0 Alias
31 /*	expansion error".
32 /* SEE ALSO
33 /*	mail_addr_map(3) address mappings
34 /*	mail_addr_find(3) address lookups
35 /* LICENSE
36 /* .ad
37 /* .fi
38 /*	The Secure Mailer license must be distributed with this software.
39 /* AUTHOR(S)
40 /*	Wietse Venema
41 /*	IBM T.J. Watson Research
42 /*	P.O. Box 704
43 /*	Yorktown Heights, NY 10598, USA
44 /*--*/
45 
46 /* System library. */
47 
48 #include <sys_defs.h>
49 #include <string.h>
50 
51 #ifdef STRCASECMP_IN_STRINGS_H
52 #include <strings.h>
53 #endif
54 
55 /* Utility library. */
56 
57 #include <mymalloc.h>
58 #include <msg.h>
59 #include <argv.h>
60 #include <vstring.h>
61 #include <dict.h>
62 
63 /* Global library. */
64 
65 #include <mail_params.h>
66 #include <mail_addr_map.h>
67 #include <cleanup_user.h>
68 #include <quote_822_local.h>
69 #include <been_here.h>
70 
71 /* Application-specific. */
72 
73 #include "cleanup.h"
74 
75 /* cleanup_map1n_internal - one-to-many table lookups */
76 
77 ARGV   *cleanup_map1n_internal(CLEANUP_STATE *state, const char *addr,
78 			               MAPS *maps, int propagate)
79 {
80     ARGV   *argv;
81     ARGV   *lookup;
82     int     count;
83     int     i;
84     int     arg;
85     BH_TABLE *been_here;
86     char   *saved_lhs;
87 
88     /*
89      * Initialize.
90      */
91     argv = argv_alloc(1);
92     argv_add(argv, addr, ARGV_END);
93     argv_terminate(argv);
94     been_here = been_here_init(0, BH_FLAG_FOLD);
95 
96     /*
97      * Rewrite the address vector in place. With each map lookup result,
98      * split it into separate addresses, then rewrite and flatten each
99      * address, and repeat the process. Beware: argv is being changed, so we
100      * must index the array explicitly, instead of running along it with a
101      * pointer.
102      */
103 #define UPDATE(ptr,new)	do { \
104 	if (ptr) myfree(ptr); ptr = mystrdup(new); \
105     } while (0)
106 #define STR	vstring_str
107 #define RETURN(x) do { \
108 	been_here_free(been_here); return (x); \
109     } while (0)
110 #define UNEXPAND(argv, addr) do { \
111 	argv_truncate((argv), 0); argv_add((argv), (addr), (char *) 0); \
112     } while (0)
113 
114     for (arg = 0; arg < argv->argc; arg++) {
115 	if (argv->argc > var_virt_expan_limit) {
116 	    msg_warn("%s: unreasonable %s map expansion size for %s -- "
117 		     "deferring delivery",
118 		     state->queue_id, maps->title, addr);
119 	    state->errs |= CLEANUP_STAT_DEFER;
120 	    UPDATE(state->reason, "4.6.0 Alias expansion error");
121 	    UNEXPAND(argv, addr);
122 	    RETURN(argv);
123 	}
124 	for (count = 0; /* void */ ; count++) {
125 
126 	    /*
127 	     * Don't expand an address that already expanded into itself.
128 	     */
129 	    if (been_here_check_fixed(been_here, argv->argv[arg]) != 0)
130 		break;
131 	    if (count >= var_virt_recur_limit) {
132 		msg_warn("%s: unreasonable %s map nesting for %s -- "
133 			 "deferring delivery",
134 			 state->queue_id, maps->title, addr);
135 		state->errs |= CLEANUP_STAT_DEFER;
136 		UPDATE(state->reason, "4.6.0 Alias expansion error");
137 		UNEXPAND(argv, addr);
138 		RETURN(argv);
139 	    }
140 	    quote_822_local(state->temp1, argv->argv[arg]);
141 	    if ((lookup = mail_addr_map(maps, STR(state->temp1), propagate)) != 0) {
142 		saved_lhs = mystrdup(argv->argv[arg]);
143 		for (i = 0; i < lookup->argc; i++) {
144 		    unquote_822_local(state->temp1, lookup->argv[i]);
145 		    if (i == 0) {
146 			UPDATE(argv->argv[arg], STR(state->temp1));
147 		    } else {
148 			argv_add(argv, STR(state->temp1), ARGV_END);
149 			argv_terminate(argv);
150 		    }
151 
152 		    /*
153 		     * Allow an address to expand into itself once.
154 		     */
155 		    if (strcasecmp(saved_lhs, STR(state->temp1)) == 0)
156 			been_here_fixed(been_here, saved_lhs);
157 		}
158 		myfree(saved_lhs);
159 		argv_free(lookup);
160 	    } else if (dict_errno != 0) {
161 		msg_warn("%s: %s map lookup problem for %s -- "
162 			 "deferring delivery",
163 			 state->queue_id, maps->title, addr);
164 		state->errs |= CLEANUP_STAT_WRITE;
165 		UPDATE(state->reason, "4.6.0 Alias expansion error");
166 		UNEXPAND(argv, addr);
167 		RETURN(argv);
168 	    } else {
169 		break;
170 	    }
171 	}
172     }
173     RETURN(argv);
174 }
175