+/*
+ * checkalias.c -- check to see if two hostnames or IP addresses are equivalent
+ *
+ * Copyright 1997 by Eric S. Raymond
+ * For license terms, see the file COPYING in this directory.
+ */
+#include "config.h"
+#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <sys/types.h>
-#include <sys/socket.h>
-#include <netinet/in.h>
-#include <arpa/inet.h>
-#include <netdb.h>
-#include "fetchmail.h"
-
-
-int is_ip_alias(const char *name1,const char *name2)
-/* Given two hostnames as arguments, returns TRUE if they
- * have at least one IP address in common.
- * It is meant to be called by the is_host_alias() function in driver.c
- * No check is done on errors returned by gethostbyname,
- * the calling function does them.
- */
- {
-
- typedef unsigned char address_t[sizeof (struct in_addr)];
- typedef struct _address_e { struct _address_e *next;
- address_t address;
- } address_e;
-
- address_e *host_a_addr, *host_b_addr,*dummy_addr;
-
- int i;
-
- struct hostent *hp;
-
- char **p;
-
- hp = gethostbyname(name1);
-
- dummy_addr = (address_e *)NULL;
-
- for (i=0,p = hp->h_addr_list; *p != 0; i++,p++) {
- struct in_addr in;
- (void) memcpy(&in.s_addr, *p, sizeof (in.s_addr));
- host_a_addr = (address_e *)xmalloc(sizeof( address_e));
- memset (host_a_addr,0, sizeof (address_e));
- host_a_addr->next = dummy_addr;
- (void) memcpy(&host_a_addr->address, *p, sizeof (in.s_addr));
- dummy_addr = host_a_addr;
- }
+#include "fetchmail.h"
- hp = gethostbyname(name2);
+int is_host_alias(const char *name, struct query *ctl, struct addrinfo **res)
+/* determine whether name is a DNS alias of the mailserver for this query */
+{
+ struct idlist *idl;
+ size_t namelen;
- dummy_addr = (address_e *)NULL;
+ struct hostdata *lead_server =
+ ctl->server.lead_server ? ctl->server.lead_server : &ctl->server;
- for (i=0,p = hp->h_addr_list; *p != 0; i++,p++) {
- struct in_addr in;
- (void) memcpy(&in.s_addr, *p, sizeof (in.s_addr));
- host_b_addr = (address_e *)xmalloc(sizeof( address_e));
- memset (host_b_addr,0, sizeof (address_e));
- host_b_addr->next = dummy_addr;
- (void) memcpy(&host_b_addr->address, *p, sizeof (in.s_addr));
- dummy_addr = host_b_addr;
- }
+ /*
+ * The first two checks are optimizations that will catch a good
+ * many cases.
+ *
+ * (1) check against the `true name' deduced from the poll label
+ * and the via option (if present) at the beginning of the poll cycle.
+ * Odds are good this will either be the mailserver's FQDN or a suffix of
+ * it with the mailserver's domain's default host name omitted.
+ *
+ * (2) Then check the rest of the `also known as'
+ * cache accumulated by previous DNS checks. This cache is primed
+ * by the aka list option.
+ *
+ * Any of these on a mail address is definitive. Only if the
+ * name doesn't match any is it time to call the bind library.
+ * If this happens odds are good we're looking at an MX name.
+ */
+ if (strcasecmp(lead_server->truename, name) == 0)
+ return(TRUE);
+ else if (str_in_list(&lead_server->akalist, name, TRUE))
+ return(TRUE);
- while (host_a_addr) {
- while (host_b_addr) {
+ /*
+ * Now check for a suffix match on the akalist. The theory here is
+ * that if the user says `aka netaxs.com', we actually want to match
+ * foo.netaxs.com and bar.netaxs.com.
+ */
+ namelen = strlen(name);
+ for (idl = lead_server->akalist; idl; idl = idl->next)
+ {
+ const char *ep;
- if (!memcmp(host_b_addr->address,host_a_addr->address, sizeof (address_t))) return (TRUE);
+ /*
+ * Test is >= here because str_in_list() should have caught the
+ * equal-length case above. Doing it this way guarantees that
+ * ep[-1] is a valid reference.
+ */
+ if (strlen(idl->id) >= namelen)
+ continue;
+ ep = name + (namelen - strlen(idl->id));
+ /* a suffix led by . must match */
+ if (ep[-1] == '.' && !strcasecmp(ep, idl->id))
+ return(TRUE);
+ }
- host_b_addr = host_b_addr->next;
- }
- host_a_addr = host_a_addr->next;
- }
-return (FALSE);
+ if (!ctl->server.dns)
+ return(FALSE);
+ (void)res;
+ return(FALSE);
}
+/* checkalias.c ends here */
projects / ~andy / fetchmail / blobdiff