xref: /netbsd-src/external/ibm-public/postfix/dist/src/cleanup/cleanup_map1n.c (revision c48c605c14fd8622b523d1d6a3f0c0bad133ea89)
1 /*	$NetBSD: cleanup_map1n.c,v 1.4 2023/12/23 20:30:43 christos 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 /*	Wietse Venema
46 /*	Google, Inc.
47 /*	111 8th Avenue
48 /*	New York, NY 10011, USA
49 /*--*/
50 
51 /* System library. */
52 
53 #include <sys_defs.h>
54 #include <string.h>
55 
56 /* Utility library. */
57 
58 #include <mymalloc.h>
59 #include <msg.h>
60 #include <argv.h>
61 #include <vstring.h>
62 #include <dict.h>
63 #include <stringops.h>
64 
65 /* Global library. */
66 
67 #include <mail_params.h>
68 #include <mail_addr_map.h>
69 #include <cleanup_user.h>
70 #include <quote_822_local.h>
71 #include <been_here.h>
72 
73 /* Application-specific. */
74 
75 #include "cleanup.h"
76 
77 /* cleanup_map1n_internal - one-to-many table lookups */
78 
cleanup_map1n_internal(CLEANUP_STATE * state,const char * addr,MAPS * maps,int propagate)79 ARGV   *cleanup_map1n_internal(CLEANUP_STATE *state, const char *addr,
80 			               MAPS *maps, int propagate)
81 {
82     ARGV   *argv;
83     ARGV   *lookup;
84     int     count;
85     int     i;
86     int     arg;
87     BH_TABLE *been_here;
88     char   *saved_lhs;
89 
90     /*
91      * Initialize.
92      */
93     argv = argv_alloc(1);
94     argv_add(argv, addr, ARGV_END);
95     argv_terminate(argv);
96     been_here = been_here_init(0, BH_FLAG_FOLD);
97 
98     /*
99      * Rewrite the address vector in place. With each map lookup result,
100      * split it into separate addresses, then rewrite and flatten each
101      * address, and repeat the process. Beware: argv is being changed, so we
102      * must index the array explicitly, instead of running along it with a
103      * pointer.
104      */
105 #define UPDATE(ptr,new)	do { \
106 	if (ptr) { myfree(ptr); } ptr = mystrdup(new); \
107     } while (0)
108 #define STR	vstring_str
109 #define RETURN(x) do { \
110 	been_here_free(been_here); return (x); \
111     } while (0)
112 #define UNEXPAND(argv, addr) do { \
113 	argv_truncate((argv), 0); argv_add((argv), (addr), (char *) 0); \
114     } while (0)
115 
116     for (arg = 0; arg < argv->argc; arg++) {
117 	if (argv->argc > var_virt_expan_limit) {
118 	    msg_warn("%s: unreasonable %s map expansion size for %s -- "
119 		     "message not accepted, try again later",
120 		     state->queue_id, maps->title, addr);
121 	    state->errs |= CLEANUP_STAT_DEFER;
122 	    UPDATE(state->reason, "4.6.0 Alias expansion error");
123 	    UNEXPAND(argv, addr);
124 	    RETURN(argv);
125 	}
126 	for (count = 0; /* void */ ; count++) {
127 
128 	    /*
129 	     * Don't expand an address that already expanded into itself.
130 	     */
131 	    if (been_here_check_fixed(been_here, argv->argv[arg]) != 0)
132 		break;
133 	    if (count >= var_virt_recur_limit) {
134 		msg_warn("%s: unreasonable %s map nesting for %s -- "
135 			 "message not accepted, try again later",
136 			 state->queue_id, maps->title, addr);
137 		state->errs |= CLEANUP_STAT_DEFER;
138 		UPDATE(state->reason, "4.6.0 Alias expansion error");
139 		UNEXPAND(argv, addr);
140 		RETURN(argv);
141 	    }
142 	    if ((lookup = mail_addr_map_internal(maps, argv->argv[arg],
143 						 propagate)) != 0) {
144 		saved_lhs = mystrdup(argv->argv[arg]);
145 		for (i = 0; i < lookup->argc; i++) {
146 		    if (strlen(lookup->argv[i]) > var_virt_addrlen_limit) {
147 			msg_warn("%s: unreasonable %s result %.300s... -- "
148 				 "message not accepted, try again later",
149 			     state->queue_id, maps->title, lookup->argv[i]);
150 			state->errs |= CLEANUP_STAT_DEFER;
151 			UPDATE(state->reason, "4.6.0 Alias expansion error");
152 			UNEXPAND(argv, addr);
153 			RETURN(argv);
154 		    }
155 		    if (i == 0) {
156 			UPDATE(argv->argv[arg], lookup->argv[i]);
157 		    } else {
158 			argv_add(argv, lookup->argv[i], ARGV_END);
159 			argv_terminate(argv);
160 		    }
161 
162 		    /*
163 		     * Allow an address to expand into itself once.
164 		     */
165 		    if (strcasecmp_utf8(saved_lhs, lookup->argv[i]) == 0)
166 			been_here_fixed(been_here, saved_lhs);
167 		}
168 		myfree(saved_lhs);
169 		argv_free(lookup);
170 	    } else if (maps->error != 0) {
171 		msg_warn("%s: %s map lookup problem for %s -- "
172 			 "message not accepted, try again later",
173 			 state->queue_id, maps->title, addr);
174 		state->errs |= CLEANUP_STAT_WRITE;
175 		UPDATE(state->reason, "4.6.0 Alias expansion error");
176 		UNEXPAND(argv, addr);
177 		RETURN(argv);
178 	    } else {
179 		break;
180 	    }
181 	}
182     }
183     RETURN(argv);
184 }
185