2 * socktoa - return a numeric host name from a sockaddr_storage structure
6 #ifdef HAVE_SYS_SOCKET_H
7 #include <sys/socket.h>
9 #ifdef HAVE_NETINET_IN_H
10 #include <netinet/in.h>
13 #include <arpa/inet.h>
18 #include "lib_strbuf.h"
19 #include "ntp_stdlib.h"
21 #include "ntp_debug.h"
26 const sockaddr_u *sock
29 const char svc[] = "ntp";
33 struct addrinfo hints;
34 struct addrinfo * alist;
41 saved_errno = socket_errno();
43 /* reverse the address to purported DNS name */
45 gni_flags = NI_DGRAM | NI_NAMEREQD;
46 if (getnameinfo(&sock->sa, SOCKLEN(sock), pbuf, LIB_BUFLENGTH,
47 NULL, 0, gni_flags)) {
49 return stoa(sock); /* use address */
52 TRACE(1, ("%s reversed to %s\n", stoa(sock), pbuf));
55 * Resolve the reversed name and make sure the reversed address
56 * is among the results.
59 hints.ai_family = AF(sock);
60 hints.ai_protocol = IPPROTO_UDP;
61 hints.ai_socktype = SOCK_DGRAM;
65 a_info = getaddrinfo(pbuf, svc, &hints, &alist);
66 if (a_info == EAI_NONAME
68 || a_info == EAI_NODATA
71 hints.ai_flags = AI_CANONNAME;
73 hints.ai_flags |= AI_ADDRCONFIG;
75 a_info = getaddrinfo(pbuf, svc, &hints, &alist);
78 /* Some older implementations don't like AI_ADDRCONFIG. */
79 if (a_info == EAI_BADFLAGS) {
80 hints.ai_flags &= ~AI_ADDRCONFIG;
81 a_info = getaddrinfo(pbuf, svc, &hints, &alist);
87 INSIST(alist != NULL);
89 for (ai = alist; ai != NULL; ai = ai->ai_next) {
91 * Make a convenience sockaddr_u copy from ai->ai_addr
92 * because casting from sockaddr * to sockaddr_u * is
93 * risking alignment problems on platforms where
94 * sockaddr_u has stricter alignment than sockaddr,
98 octets = min(sizeof(addr), ai->ai_addrlen);
99 memcpy(&addr, ai->ai_addr, octets);
100 if (SOCK_EQ(sock, &addr))
107 return pbuf; /* forward check passed */
111 TRACE(1, ("%s forward check lookup fail: %s\n", pbuf,
112 gai_strerror(a_info)));
114 snprintf(pliar, LIB_BUFLENGTH, "%s (%s)", stoa(sock), pbuf);