1 5cdb1798 2005-10-29 devnull #include "common.h"
  2 5cdb1798 2005-10-29 devnull #include <ndb.h>
  3 5cdb1798 2005-10-29 devnull #include "smtp.h"	/* to publish dial_string_parse */
  4 b5f65921 2006-02-11 devnull #include <ip.h>
  5 5cdb1798 2005-10-29 devnull 
  6 5cdb1798 2005-10-29 devnull enum
  7 5cdb1798 2005-10-29 devnull {
  8 5cdb1798 2005-10-29 devnull 	Nmx=	16,
  9 cbeb0b26 2006-04-01 devnull 	Maxstring=	256
 10 5cdb1798 2005-10-29 devnull };
 11 5cdb1798 2005-10-29 devnull 
 12 5cdb1798 2005-10-29 devnull typedef struct Mx	Mx;
 13 5cdb1798 2005-10-29 devnull struct Mx
 14 5cdb1798 2005-10-29 devnull {
 15 5cdb1798 2005-10-29 devnull 	char host[256];
 16 5cdb1798 2005-10-29 devnull 	char ip[24];
 17 5cdb1798 2005-10-29 devnull 	int pref;
 18 5cdb1798 2005-10-29 devnull };
 19 5cdb1798 2005-10-29 devnull static Mx mx[Nmx];
 20 5cdb1798 2005-10-29 devnull 
 21 5cdb1798 2005-10-29 devnull Ndb *db;
 22 5cdb1798 2005-10-29 devnull extern int debug;
 23 5cdb1798 2005-10-29 devnull 
 24 5cdb1798 2005-10-29 devnull static int	mxlookup(DS*, char*);
 25 a79cd783 2006-02-12 devnull static int	compar(const void*, const void*);
 26 5cdb1798 2005-10-29 devnull static int	callmx(DS*, char*, char*);
 27 5cdb1798 2005-10-29 devnull static void expand_meta(DS *ds);
 28 5cdb1798 2005-10-29 devnull extern int	cistrcmp(char*, char*);
 29 5cdb1798 2005-10-29 devnull 
 30 5cdb1798 2005-10-29 devnull int
 31 5cdb1798 2005-10-29 devnull mxdial(char *addr, char *ddomain, char *gdomain)
 32 5cdb1798 2005-10-29 devnull {
 33 5cdb1798 2005-10-29 devnull 	int fd;
 34 5cdb1798 2005-10-29 devnull 	DS ds;
 35 5cdb1798 2005-10-29 devnull 	char err[Errlen];
 36 5cdb1798 2005-10-29 devnull 
 37 5cdb1798 2005-10-29 devnull 	addr = netmkaddr(addr, 0, "smtp");
 38 5cdb1798 2005-10-29 devnull 	dial_string_parse(addr, &ds);
 39 5cdb1798 2005-10-29 devnull 
 40 5cdb1798 2005-10-29 devnull 	/* try connecting to destination or any of it's mail routers */
 41 5cdb1798 2005-10-29 devnull 	fd = callmx(&ds, addr, ddomain);
 42 5cdb1798 2005-10-29 devnull 
 43 5cdb1798 2005-10-29 devnull 	/* try our mail gateway */
 44 5cdb1798 2005-10-29 devnull 	rerrstr(err, sizeof(err));
 45 b5f65921 2006-02-11 devnull 	if(fd < 0 && gdomain && strstr(err, "can't translate") != 0)
 46 5cdb1798 2005-10-29 devnull 		fd = dial(netmkaddr(gdomain, 0, "smtp"), 0, 0, 0);
 47 5cdb1798 2005-10-29 devnull 
 48 5cdb1798 2005-10-29 devnull 	return fd;
 49 b5f65921 2006-02-11 devnull }
 50 b5f65921 2006-02-11 devnull 
 51 b5f65921 2006-02-11 devnull static int
 52 a79cd783 2006-02-12 devnull timeout(void *v, char *msg)
 53 b5f65921 2006-02-11 devnull {
 54 a79cd783 2006-02-12 devnull 	USED(v);
 55 a79cd783 2006-02-12 devnull 
 56 b5f65921 2006-02-11 devnull 	if(strstr(msg, "alarm"))
 57 b5f65921 2006-02-11 devnull 		return 1;
 58 b5f65921 2006-02-11 devnull 	return 0;
 59 5cdb1798 2005-10-29 devnull }
 60 5cdb1798 2005-10-29 devnull 
 61 5cdb1798 2005-10-29 devnull /*
 62 5cdb1798 2005-10-29 devnull  *  take an address and return all the mx entries for it,
 63 5cdb1798 2005-10-29 devnull  *  most preferred first
 64 5cdb1798 2005-10-29 devnull  */
 65 5cdb1798 2005-10-29 devnull static int
 66 5cdb1798 2005-10-29 devnull callmx(DS *ds, char *dest, char *domain)
 67 5cdb1798 2005-10-29 devnull {
 68 5cdb1798 2005-10-29 devnull 	int fd, i, nmx;
 69 5cdb1798 2005-10-29 devnull 	char addr[Maxstring];
 70 5cdb1798 2005-10-29 devnull 
 71 5cdb1798 2005-10-29 devnull 	/* get a list of mx entries */
 72 5cdb1798 2005-10-29 devnull 	nmx = mxlookup(ds, domain);
 73 5cdb1798 2005-10-29 devnull 	if(nmx < 0){
 74 5cdb1798 2005-10-29 devnull 		/* dns isn't working, don't just dial */
 75 5cdb1798 2005-10-29 devnull 		return -1;
 76 5cdb1798 2005-10-29 devnull 	}
 77 5cdb1798 2005-10-29 devnull 	if(nmx == 0){
 78 5cdb1798 2005-10-29 devnull 		if(debug)
 79 5cdb1798 2005-10-29 devnull 			fprint(2, "mxlookup returns nothing\n");
 80 5cdb1798 2005-10-29 devnull 		return dial(dest, 0, 0, 0);
 81 5cdb1798 2005-10-29 devnull 	}
 82 5cdb1798 2005-10-29 devnull 
 83 5cdb1798 2005-10-29 devnull 	/* refuse to honor loopback addresses given by dns */
 84 5cdb1798 2005-10-29 devnull 	for(i = 0; i < nmx; i++){
 85 5cdb1798 2005-10-29 devnull 		if(strcmp(mx[i].ip, "127.0.0.1") == 0){
 86 5cdb1798 2005-10-29 devnull 			if(debug)
 87 5cdb1798 2005-10-29 devnull 				fprint(2, "mxlookup returns loopback\n");
 88 5cdb1798 2005-10-29 devnull 			werrstr("illegal: domain lists 127.0.0.1 as mail server");
 89 5cdb1798 2005-10-29 devnull 			return -1;
 90 5cdb1798 2005-10-29 devnull 		}
 91 5cdb1798 2005-10-29 devnull 	}
 92 5cdb1798 2005-10-29 devnull 
 93 5cdb1798 2005-10-29 devnull 	/* sort by preference */
 94 5cdb1798 2005-10-29 devnull 	if(nmx > 1)
 95 5cdb1798 2005-10-29 devnull 		qsort(mx, nmx, sizeof(Mx), compar);
 96 5cdb1798 2005-10-29 devnull 
 97 e269d00c 2006-02-25 devnull 	if(debug){
 98 e269d00c 2006-02-25 devnull 		for(i=0; i<nmx; i++)
 99 e269d00c 2006-02-25 devnull 			print("%s %d\n", mx[i].host, mx[i].pref);
100 e269d00c 2006-02-25 devnull 	}
101 5cdb1798 2005-10-29 devnull 	/* dial each one in turn */
102 5cdb1798 2005-10-29 devnull 	for(i = 0; i < nmx; i++){
103 5cdb1798 2005-10-29 devnull 		snprint(addr, sizeof(addr), "%s/%s!%s!%s", ds->netdir, ds->proto,
104 5cdb1798 2005-10-29 devnull 			mx[i].host, ds->service);
105 5cdb1798 2005-10-29 devnull 		if(debug)
106 fe02cd59 2006-03-03 devnull 			fprint(2, "mxdial trying %s (%d)\n", addr, i);
107 b5f65921 2006-02-11 devnull 		atnotify(timeout, 1);
108 b5f65921 2006-02-11 devnull 		alarm(10*1000);
109 5cdb1798 2005-10-29 devnull 		fd = dial(addr, 0, 0, 0);
110 b5f65921 2006-02-11 devnull 		alarm(0);
111 b5f65921 2006-02-11 devnull 		atnotify(timeout, 0);
112 5cdb1798 2005-10-29 devnull 		if(fd >= 0)
113 5cdb1798 2005-10-29 devnull 			return fd;
114 5cdb1798 2005-10-29 devnull 	}
115 5cdb1798 2005-10-29 devnull 	return -1;
116 5cdb1798 2005-10-29 devnull }
117 5cdb1798 2005-10-29 devnull 
118 5cdb1798 2005-10-29 devnull /*
119 5cc53af9 2006-02-12 devnull  *  use dns to resolve the mx request
120 5cdb1798 2005-10-29 devnull  */
121 5cdb1798 2005-10-29 devnull static int
122 5cdb1798 2005-10-29 devnull mxlookup(DS *ds, char *domain)
123 5cdb1798 2005-10-29 devnull {
124 5cc53af9 2006-02-12 devnull 	int i, n, nmx;
125 5cc53af9 2006-02-12 devnull 	Ndbtuple *t, *tmx, *tpref, *tip;
126 5cc53af9 2006-02-12 devnull 	
127 5cc53af9 2006-02-12 devnull 	ds->netdir = "/net";
128 5cdb1798 2005-10-29 devnull 	nmx = 0;
129 5cc53af9 2006-02-12 devnull 	if((t = dnsquery(nil, ds->host, "mx")) != nil){
130 5cc53af9 2006-02-12 devnull 		for(tmx=t; (tmx=ndbfindattr(tmx->entry, nil, "mx")) != nil && nmx<Nmx; ){
131 e269d00c 2006-02-25 devnull 			for(tpref=tmx->line; tpref != tmx; tpref=tpref->line){
132 5cc53af9 2006-02-12 devnull 				if(strcmp(tpref->attr, "pref") == 0){
133 5cc53af9 2006-02-12 devnull 					strncpy(mx[nmx].host, tmx->val, sizeof(mx[n].host)-1);
134 5cc53af9 2006-02-12 devnull 					mx[nmx].pref = atoi(tpref->val);
135 5cc53af9 2006-02-12 devnull 					nmx++;
136 5cc53af9 2006-02-12 devnull 					break;
137 5cc53af9 2006-02-12 devnull 				}
138 5cc53af9 2006-02-12 devnull 			}	
139 5cdb1798 2005-10-29 devnull 		}
140 5cc53af9 2006-02-12 devnull 		ndbfree(t);
141 5cdb1798 2005-10-29 devnull 	}
142 5cdb1798 2005-10-29 devnull 
143 5cdb1798 2005-10-29 devnull 	/*
144 5cdb1798 2005-10-29 devnull 	 * no mx record? try name itself.
145 5cdb1798 2005-10-29 devnull 	 */
146 5cdb1798 2005-10-29 devnull 	/*
147 5cdb1798 2005-10-29 devnull 	 * BUG? If domain has no dots, then we used to look up ds->host
148 5cdb1798 2005-10-29 devnull 	 * but return domain instead of ds->host in the list.  Now we return
149 5cdb1798 2005-10-29 devnull 	 * ds->host.  What will this break?
150 5cdb1798 2005-10-29 devnull 	 */
151 5cdb1798 2005-10-29 devnull 	if(nmx == 0){
152 5cdb1798 2005-10-29 devnull 		mx[0].pref = 1;
153 5cdb1798 2005-10-29 devnull 		strncpy(mx[0].host, ds->host, sizeof(mx[0].host));
154 5cdb1798 2005-10-29 devnull 		nmx++;
155 5cdb1798 2005-10-29 devnull 	}
156 5cdb1798 2005-10-29 devnull 
157 5cdb1798 2005-10-29 devnull 	/*
158 5cdb1798 2005-10-29 devnull 	 * look up all ip addresses
159 5cdb1798 2005-10-29 devnull 	 */
160 5cdb1798 2005-10-29 devnull 	for(i = 0; i < nmx; i++){
161 5cc53af9 2006-02-12 devnull 		if((t = dnsquery(nil, mx[i].host, "ip")) == nil)
162 5cdb1798 2005-10-29 devnull 			goto no;
163 5cc53af9 2006-02-12 devnull 		if((tip = ndbfindattr(t, nil, "ip")) == nil){
164 5cc53af9 2006-02-12 devnull 			ndbfree(t);
165 5cdb1798 2005-10-29 devnull 			goto no;
166 5cc53af9 2006-02-12 devnull 		}
167 5cc53af9 2006-02-12 devnull 		strncpy(mx[i].ip, tip->val, sizeof(mx[i].ip)-1);
168 5cc53af9 2006-02-12 devnull 		ndbfree(t);
169 5cdb1798 2005-10-29 devnull 		continue;
170 5cc53af9 2006-02-12 devnull 	
171 5cdb1798 2005-10-29 devnull 	no:
172 5cdb1798 2005-10-29 devnull 		/* remove mx[i] and go around again */
173 5cdb1798 2005-10-29 devnull 		nmx--;
174 5cdb1798 2005-10-29 devnull 		mx[i] = mx[nmx];
175 5cdb1798 2005-10-29 devnull 		i--;
176 5cdb1798 2005-10-29 devnull 	}
177 5cdb1798 2005-10-29 devnull 	return nmx;		
178 5cdb1798 2005-10-29 devnull }
179 5cdb1798 2005-10-29 devnull 
180 5cdb1798 2005-10-29 devnull static int
181 a79cd783 2006-02-12 devnull compar(const void *a, const void *b)
182 5cdb1798 2005-10-29 devnull {
183 5cdb1798 2005-10-29 devnull 	return ((Mx*)a)->pref - ((Mx*)b)->pref;
184 5cdb1798 2005-10-29 devnull }
185 5cdb1798 2005-10-29 devnull 
186 5cdb1798 2005-10-29 devnull /* break up an address to its component parts */
187 5cdb1798 2005-10-29 devnull void
188 5cdb1798 2005-10-29 devnull dial_string_parse(char *str, DS *ds)
189 5cdb1798 2005-10-29 devnull {
190 5cdb1798 2005-10-29 devnull 	char *p, *p2;
191 5cdb1798 2005-10-29 devnull 
192 5cdb1798 2005-10-29 devnull 	strncpy(ds->buf, str, sizeof(ds->buf));
193 5cdb1798 2005-10-29 devnull 	ds->buf[sizeof(ds->buf)-1] = 0;
194 5cdb1798 2005-10-29 devnull 
195 5cdb1798 2005-10-29 devnull 	p = strchr(ds->buf, '!');
196 5cdb1798 2005-10-29 devnull 	if(p == 0) {
197 5cdb1798 2005-10-29 devnull 		ds->netdir = 0;
198 5cdb1798 2005-10-29 devnull 		ds->proto = "net";
199 5cdb1798 2005-10-29 devnull 		ds->host = ds->buf;
200 5cdb1798 2005-10-29 devnull 	} else {
201 5cdb1798 2005-10-29 devnull 		if(*ds->buf != '/'){
202 5cdb1798 2005-10-29 devnull 			ds->netdir = 0;
203 5cdb1798 2005-10-29 devnull 			ds->proto = ds->buf;
204 5cdb1798 2005-10-29 devnull 		} else {
205 5cdb1798 2005-10-29 devnull 			for(p2 = p; *p2 != '/'; p2--)
206 5cdb1798 2005-10-29 devnull 				;
207 5cdb1798 2005-10-29 devnull 			*p2++ = 0;
208 5cdb1798 2005-10-29 devnull 			ds->netdir = ds->buf;
209 5cdb1798 2005-10-29 devnull 			ds->proto = p2;
210 5cdb1798 2005-10-29 devnull 		}
211 5cdb1798 2005-10-29 devnull 		*p = 0;
212 5cdb1798 2005-10-29 devnull 		ds->host = p + 1;
213 5cdb1798 2005-10-29 devnull 	}
214 5cdb1798 2005-10-29 devnull 	ds->service = strchr(ds->host, '!');
215 5cdb1798 2005-10-29 devnull 	if(ds->service)
216 5cdb1798 2005-10-29 devnull 		*ds->service++ = 0;
217 5cdb1798 2005-10-29 devnull 	if(*ds->host == '$')
218 5cdb1798 2005-10-29 devnull 		expand_meta(ds);
219 5cdb1798 2005-10-29 devnull }
220 5cdb1798 2005-10-29 devnull 
221 5cdb1798 2005-10-29 devnull static void
222 5cdb1798 2005-10-29 devnull expand_meta(DS *ds)
223 5cdb1798 2005-10-29 devnull {
224 5cc53af9 2006-02-12 devnull 	static Ndb *db;
225 5cdb1798 2005-10-29 devnull 	Ndbs s;
226 5cdb1798 2005-10-29 devnull 	char *sys, *smtpserver;
227 5cdb1798 2005-10-29 devnull 
228 5cc53af9 2006-02-12 devnull 	/* can't ask cs, so query database directly. */
229 5cdb1798 2005-10-29 devnull 	sys = sysname();
230 5cc53af9 2006-02-12 devnull 	if(db == nil)
231 5cc53af9 2006-02-12 devnull 		db = ndbopen(0);
232 5cdb1798 2005-10-29 devnull 	smtpserver = ndbgetvalue(db, &s, "sys", sys, "smtp", nil);
233 5cc53af9 2006-02-12 devnull 	snprint(ds->host, 128, "%s", smtpserver);
234 5cdb1798 2005-10-29 devnull }