Virgin import of ntpd 4.2.0

1 files changed, 221 insertions, 0 deletions

diff --git a/contrib/ntp/sntp/internet.c b/contrib/ntp/sntp/internet.c
new file mode 100644
index 0000000..2d23e50
--- /dev/null
+++ b/contrib/ntp/sntp/internet.c
@@ -0,0 +1,221 @@
+/*  Copyright (C) 1996 N.M. Maclaren
+    Copyright (C) 1996 The University of Cambridge
+
+This includes all of the code needed to handle Internet addressing.  It is way
+outside current POSIX, unfortunately.  It should be easy to convert to a system
+that uses another mechanism.  The signal handling is not necessary for its
+function, but is an attempt to avoid the program hanging when the name server
+is inaccessible. */
+
+
+
+#include "header.h"
+#include "internet.h"
+
+#include <netdb.h>
+#include <arpa/inet.h>
+
+#define INTERNET
+#include "kludges.h"
+#undef INTERNET
+
+
+/* Used to force dns resolving to ipv4 or ipv6 addresses. */
+static int pref_family;
+
+/* There needs to be some disgusting grobble for handling timeouts, which is
+identical to the grobble in socket.c. */
+
+static jmp_buf jump_buffer;
+
+static void jump_handler (int sig) {
+    longjmp(jump_buffer,1);
+}
+
+static void clear_alarm (void) {
+    int k;
+
+    k = errno;
+    alarm(0);
+    errno = 0;
+    if (signal(SIGALRM,SIG_DFL) == SIG_ERR)
+        fatal(1,"unable to reset signal handler",NULL);
+    errno = k;
+}
+
+void preferred_family(int fam) {
+	switch(fam) {
+	case PREF_FAM_INET:
+	    pref_family = AF_INET;
+	    break;
+#ifdef HAVE_IPV6
+	case PREF_FAM_INET6:
+	    pref_family = AF_INET6;
+	    break;
+#endif
+	default:
+	    fatal(0,"unable to set the preferred family", NULL);
+	    break;
+	}
+}
+
+#ifdef HAVE_IPV6
+
+void find_address (struct sockaddr_storage *address,
+    struct sockaddr_storage *anywhere, struct sockaddr_storage *everywhere,
+    int *port, char *hostname, int timespan) {
+
+/* Locate the specified NTP server and return its Internet address and port 
+number. */
+
+    int family, rval;
+    struct addrinfo hints;
+    struct addrinfo *res;
+    struct sockaddr_in *sin;
+    struct sockaddr_in6 *sin6;
+
+    res = NULL;
+    memset(address, 0, sizeof(struct sockaddr_storage));
+    memset(anywhere, 0, sizeof(struct sockaddr_storage));
+    memset(everywhere, 0, sizeof(struct sockaddr_storage));
+
+    if (setjmp(jump_buffer))
+        fatal(0,"unable to set up access to NTP server %s",hostname);
+    errno = 0;
+    if (signal(SIGALRM,jump_handler) == SIG_ERR)
+        fatal(1,"unable to set up signal handler",NULL);
+    alarm((unsigned int)timespan);
+
+/* Look up the Internet name or IP number. */
+    memset(&hints, 0, sizeof(hints));
+    hints.ai_socktype = SOCK_DGRAM;
+    hints.ai_family = pref_family;
+    rval = getaddrinfo(hostname, "ntp", &hints, &res);
+    if (rval != 0)
+	fatal(0, "getaddrinfo failed with %s", gai_strerror(rval));
+
+/* Now clear the timer and check the result. */
+
+    clear_alarm();
+    /* There can be more than one address in the list, but for now only
+    use the first. */
+    memcpy(address, res->ai_addr, res->ai_addrlen);
+    family = res->ai_family;
+    freeaddrinfo(res);
+
+    switch(family) {
+    case AF_INET:
+	hints.ai_family = AF_INET;
+	hints.ai_flags = AI_PASSIVE;
+	rval = getaddrinfo(NULL, "ntp", &hints, &res);
+	if (rval != 0)
+	    fatal(0, "getaddrinfo failed with %s", gai_strerror(rval));
+	memcpy(anywhere, res->ai_addr, res->ai_addrlen);
+	freeaddrinfo(res);
+	rval = getaddrinfo("255.255.255.255", "ntp", &hints, &res);
+	if (rval != 0)
+	    fatal(0, "getaddrinfo failed with %s", gai_strerror(rval));
+	memcpy(everywhere, res->ai_addr, res->ai_addrlen);
+	freeaddrinfo(res);
+	break;
+    case AF_INET6:
+	hints.ai_family = AF_INET6;
+	hints.ai_flags = AI_PASSIVE;
+	rval = getaddrinfo(NULL, "ntp", &hints, &res);
+	if (rval != 0)
+	    fatal(0, "getaddrinfo failed with %s", gai_strerror(rval));
+	memcpy(anywhere, res->ai_addr, res->ai_addrlen);
+	freeaddrinfo(res);
+	/* IPv6 do not have broadcast, give it loopback. */
+	hints.ai_flags = 0;
+	rval = getaddrinfo(NULL, "ntp", &hints, &res);
+	if (rval != 0)
+	    fatal(0, "getaddrinfo failed with %s", gai_strerror(rval));
+	memcpy(everywhere, res->ai_addr, res->ai_addrlen);
+	freeaddrinfo(res);
+	break;
+    }
+}
+
+#else
+
+void find_address (struct in_addr *address, struct in_addr *anywhere,
+    struct in_addr *everywhere, int *port, char *hostname, int timespan) {
+
+/* Locate the specified NTP server and return its Internet address and port 
+number. */
+
+    unsigned long ipaddr;
+    struct in_addr nowhere[1];
+    struct hostent *host;
+    struct servent *service;
+
+/* Set up the reserved Internet addresses, attempting not to assume that
+addresses are 32 bits. */
+
+    local_to_address(nowhere,INADDR_LOOPBACK);
+    local_to_address(anywhere,INADDR_ANY);
+    local_to_address(everywhere,INADDR_BROADCAST);
+
+/* Check the address, if any.  This assumes that the DNS is reliable, or is at
+least checked by someone else.  But it doesn't assume that it is accessible, so
+it needs to set up a timeout. */
+
+    if (hostname == NULL)
+        *address = *anywhere;
+    else {
+        if (setjmp(jump_buffer))
+            fatal(0,"unable to set up access to NTP server %s",hostname);
+        errno = 0;
+        if (signal(SIGALRM,jump_handler) == SIG_ERR)
+            fatal(1,"unable to set up signal handler",NULL);
+        alarm((unsigned int)timespan);
+
+/* Look up the Internet name or IP number. */
+
+        if (! isdigit(hostname[0])) {
+            errno = 0;
+            host = gethostbyname(hostname);
+        } else {
+            if ((ipaddr = inet_addr(hostname)) == (unsigned long)-1)
+                fatal(0,"invalid IP number %s",hostname);
+            network_to_address(address,ipaddr);
+            errno = 0;
+            host = gethostbyaddr((void *)address,sizeof(struct in_addr),
+                AF_INET);
+        }
+
+/* Now clear the timer and check the result. */
+
+        clear_alarm();
+        if (host == NULL) fatal(1,"unable to locate IP address/number",NULL);
+        if (host->h_length != sizeof(struct in_addr))
+            fatal(0,"the address does not seem to be an Internet one",NULL);
+        *address = *((struct in_addr **)host->h_addr_list)[0];
+        if (memcmp(address,nowhere,sizeof(struct in_addr)) == 0 ||
+                memcmp(address,anywhere,sizeof(struct in_addr)) == 0 ||
+                memcmp(address,everywhere,sizeof(struct in_addr)) == 0)
+            fatal(0,"reserved IP numbers cannot be used",NULL);
+        if (verbose)
+            fprintf(stderr,
+                "%s: using NTP server %s (%s)\n",
+                argv0,host->h_name,inet_ntoa(*address));
+    }
+
+/* Find out the port number (usually from /etc/services), and leave it in 
+network format.  This is assumed not to be obtained from a network service!
+Note that a port number is not assumed to be 16 bits. */
+
+    if ((service = getservbyname("ntp","udp")) != NULL) {
+        *port = service->s_port;
+        if (verbose > 2)
+            fprintf(stderr,"Using port %d for NTP\n",port_to_integer(*port));
+    } else {
+        *port = NTP_PORT;
+        if (verbose)
+            fprintf(stderr,
+                "%s: assuming port %d for NTP - check /etc/services\n",
+                argv0,port_to_integer(*port));
+    }
+}
+#endif