Pi-Hole/dnsmasq
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import of dnsmasq-2.3.tar.gz

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This commit is contained in:
Simon Kelley
2004-03-10 20:04:35 +00:00
parent b49644f39f
commit 44a2a3165c
19 changed files with 1687 additions and 920 deletions
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239
src/dnsmasq.c
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@@ -16,7 +16,7 @@
#include "dnsmasq.h"
static int sigterm, sighup, sigusr1, sigusr2;
static int sigterm, sighup, sigusr1, sigalarm;
static void sig_handler(int sig)
{
@@ -26,23 +26,24 @@ static void sig_handler(int sig)
sighup = 1;
else if (sig == SIGUSR1)
sigusr1 = 1;
else if (sig == SIGUSR2)
sigusr2 = 1;
else if (sig == SIGALRM)
sigalarm = 1;
}
int main (int argc, char **argv)
{
char *int_err_string;
int cachesize = CACHESIZ;
int port = NAMESERVER_PORT;
int maxleases = MAXLEASES;
int query_port = 0;
int first_loop = 1;
unsigned long local_ttl = 0;
unsigned int options;
unsigned int options, min_leasetime;
char *runfile = RUNFILE;
time_t resolv_changed = 0;
time_t now, last = 0;
struct irec *iface, *interfaces = NULL;
struct irec *interfaces = NULL;
struct listener *listener, *listeners;
char *mxname = NULL;
char *mxtarget = NULL;
char *lease_file = NULL;
@@ -53,9 +54,9 @@ int main (int argc, char **argv)
struct iname *if_names = NULL;
struct iname *if_addrs = NULL;
struct iname *if_except = NULL;
struct iname *if_tmp;
struct server *serv_addrs = NULL;
char *dnamebuff, *packet;
int uptime_fd = -1;
struct server *servers, *last_server;
struct resolvc default_resolv = { NULL, 1, 0, RESOLVFILE };
struct resolvc *resolv = &default_resolv;
@@ -66,29 +67,33 @@ int main (int argc, char **argv)
struct dhcp_opt *dhcp_options = NULL;
char *dhcp_file = NULL, *dhcp_sname = NULL;
struct in_addr dhcp_next_server;
int leasefd = 0;
int leasefd = -1, dhcpfd = -1, dhcp_raw_fd = -1;
struct sigaction sigact;
sigset_t sigmask;
sighup = 1; /* init cache the first time through */
sigusr1 = 0; /* but don't dump */
sigusr2 = 0; /* or rescan interfaces */
sigterm = 0; /* or die */
#ifdef HAVE_BROKEN_RTC
sigalarm = 1; /* need regular lease dumps */
#else
sigalarm = 0; /* or not */
#endif
sigact.sa_handler = sig_handler;
sigact.sa_flags = 0;
sigemptyset(&sigact.sa_mask);
sigaction(SIGUSR1, &sigact, NULL);
sigaction(SIGUSR2, &sigact, NULL);
sigaction(SIGHUP, &sigact, NULL);
sigaction(SIGTERM, &sigact, NULL);
sigaction(SIGALRM, &sigact, NULL);
/* now block all the signals, they stay that way except
during the call to pselect */
sigaddset(&sigact.sa_mask, SIGUSR1);
sigaddset(&sigact.sa_mask, SIGUSR2);
sigaddset(&sigact.sa_mask, SIGTERM);
sigaddset(&sigact.sa_mask, SIGHUP);
sigaddset(&sigact.sa_mask, SIGALRM);
sigprocmask(SIG_BLOCK, &sigact.sa_mask, &sigmask);
/* These get allocated here to avoid overflowing the small stack
@@ -96,17 +101,21 @@ int main (int argc, char **argv)
maximal sixed domain name and gets passed into all the processing
code. We manage to get away with one buffer. */
dnamebuff = safe_malloc(MAXDNAME);
/* Size: we check after adding each record, so there must be
memory for the largest packet, and the largest record */
packet = safe_malloc(PACKETSZ+MAXDNAME+RRFIXEDSZ);
packet = safe_malloc(DNSMASQ_PACKETSZ);
dhcp_next_server.s_addr = 0;
options = read_opts(argc, argv, dnamebuff, &resolv, &mxname, &mxtarget, &lease_file,
&username, &groupname, &domain_suffix, &runfile,
&if_names, &if_addrs, &if_except, &bogus_addr,
&serv_addrs, &cachesize, &port, &query_port, &local_ttl, &addn_hosts,
&dhcp, &dhcp_configs, &dhcp_options,
&dhcp_file, &dhcp_sname, &dhcp_next_server);
&dhcp, &dhcp_configs, &dhcp_options,
&dhcp_file, &dhcp_sname, &dhcp_next_server, &maxleases, &min_leasetime);
/* if we cannot support binding the wildcard address, set the "bind only
interfaces in use" option */
#ifndef HAVE_UDP_SRC_DST
options |= OPT_NOWILD;
#endif
if (!lease_file)
lease_file = LEASEFILE;
@@ -121,46 +130,32 @@ int main (int argc, char **argv)
}
}
if ((int_err_string = enumerate_interfaces(&interfaces, if_names, if_addrs, if_except, dhcp, port)))
die(int_err_string, NULL);
for (if_tmp = if_names; if_tmp; if_tmp = if_tmp->next)
if (if_tmp->name && !if_tmp->found)
die("unknown interface %s", if_tmp->name);
for (if_tmp = if_addrs; if_tmp; if_tmp = if_tmp->next)
if (!if_tmp->found)
{
#ifdef HAVE_IPV6
if (if_tmp->addr.sa.sa_family == AF_INET)
inet_ntop(AF_INET, &if_tmp->addr.in.sin_addr,
dnamebuff, MAXDNAME);
else
inet_ntop(AF_INET6, &if_tmp->addr.in6.sin6_addr,
dnamebuff, MAXDNAME);
die("no interface with address %s", dnamebuff);
#else
die("no interface with address %s", inet_ntoa(if_tmp->addr.in.sin_addr));
#endif
}
interfaces = enumerate_interfaces(if_names, if_addrs, if_except, port);
if (options & OPT_NOWILD)
listeners = create_bound_listeners(interfaces);
else
listeners = create_wildcard_listeners(port);
forward_init(1);
cache_init(cachesize, options & OPT_LOG);
#ifdef HAVE_BROKEN_RTC
if ((uptime_fd = open(UPTIME, O_RDONLY)) == -1)
die("cannot open " UPTIME ":%s", NULL);
#endif
now = dnsmasq_time(uptime_fd);
if (dhcp)
{
#if !defined(HAVE_PF_PACKET) && !defined(HAVE_BPF)
die("no DHCP support available on this OS.", NULL);
#endif
for (dhcp_tmp = dhcp; dhcp_tmp; dhcp_tmp = dhcp_tmp->next)
if (!dhcp_tmp->iface)
die("No suitable interface for DHCP service at address %s", inet_ntoa(dhcp_tmp->start));
set_configs_from_cache(dhcp_configs);
leasefd = lease_init(lease_file, domain_suffix, dnamebuff, packet, time(NULL), dhcp_configs);
lease_update_dns(1); /* must follow cache_init and lease_init */
dhcp_init(&dhcpfd, &dhcp_raw_fd);
leasefd = lease_init(lease_file, domain_suffix, dnamebuff, packet, now, maxleases);
if (options & OPT_ETHERS)
dhcp_configs = dhcp_read_ethers(dhcp_configs, dnamebuff);
dhcp_update_configs(dhcp_configs);
lease_update_from_configs(dhcp_configs, domain_suffix); /* must follow cache_init and lease_init */
lease_update_file(0, now);
lease_update_dns();
}
setbuf(stdout, NULL);
@@ -198,19 +193,16 @@ int main (int argc, char **argv)
for (i=0; i<64; i++)
{
for (iface = interfaces; iface; iface = iface->next)
if (iface->fd == i)
for (listener = listeners; listener; listener = listener->next)
if (listener->fd == i)
break;
if (iface)
if (listener)
continue;
for (dhcp_tmp = dhcp; dhcp_tmp; dhcp_tmp = dhcp_tmp->next)
if (dhcp_tmp->fd == i || dhcp_tmp->rawfd == i)
break;
if (dhcp_tmp)
continue;
if (dhcp && (i == leasefd))
if (i == leasefd ||
i == uptime_fd ||
i == dhcpfd ||
i == dhcp_raw_fd)
continue;
close(i);
@@ -255,10 +247,15 @@ int main (int argc, char **argv)
sprintf(packet, "infinite");
else
sprintf(packet, "%ds", (int)dhcp_tmp->lease_time);
syslog(LOG_INFO, "DHCP on %s, IP range %s -- %s, lease time %s",
dhcp_tmp->iface, dnamebuff, inet_ntoa(dhcp_tmp->end), packet);
syslog(LOG_INFO, "DHCP, IP range %s -- %s, lease time %s",
dnamebuff, inet_ntoa(dhcp_tmp->end), packet);
}
#ifdef HAVE_BROKEN_RTC
if (dhcp)
syslog(LOG_INFO, "DHCP, %s will be written every %ds", lease_file, min_leasetime/3);
#endif
if (getuid() == 0 || geteuid() == 0)
syslog(LOG_WARNING, "failed to drop root privs");
@@ -271,8 +268,13 @@ int main (int argc, char **argv)
if (sighup)
{
cache_reload(options, dnamebuff, domain_suffix, addn_hosts);
set_configs_from_cache(dhcp_configs);
lease_update_dns(1);
if (dhcp)
{
dhcp_update_configs(dhcp_configs);
lease_update_from_configs(dhcp_configs, domain_suffix);
lease_update_file(0, now);
lease_update_dns();
}
if (resolv && (options & OPT_NO_POLL))
servers = last_server =
check_servers(reload_servers(resolv->name, dnamebuff, servers, query_port),
@@ -286,18 +288,16 @@ int main (int argc, char **argv)
sigusr1 = 0;
}
if (sigusr2)
if (sigalarm)
{
if (getuid() != 0 && port <= 1024)
syslog(LOG_ERR, "cannot re-scan interfaces unless --user=root");
else
{
syslog(LOG_INFO, "rescanning network interfaces");
int_err_string = enumerate_interfaces(&interfaces, if_names, if_addrs, if_except, NULL, port);
if (int_err_string)
syslog(LOG_ERR, int_err_string, strerror(errno));
}
sigusr2 = 0;
if (dhcp)
{
lease_update_file(1, now);
#ifdef HAVE_BROKEN_RTC
alarm(min_leasetime/3);
#endif
}
sigalarm = 0;
}
FD_ZERO(&rset);
@@ -313,19 +313,20 @@ int main (int argc, char **argv)
maxfd = serverfdp->fd;
}
for (iface = interfaces; iface; iface = iface->next)
for (listener = listeners; listener; listener = listener->next)
{
FD_SET(iface->fd, &rset);
if (iface->fd > maxfd)
maxfd = iface->fd;
FD_SET(listener->fd, &rset);
if (listener->fd > maxfd)
maxfd = listener->fd;
}
for (dhcp_tmp = dhcp; dhcp_tmp; dhcp_tmp = dhcp_tmp->next)
if (dhcp)
{
FD_SET(dhcp_tmp->fd, &rset);
if (dhcp_tmp->fd > maxfd)
maxfd = dhcp_tmp->fd;
FD_SET(dhcpfd, &rset);
if (dhcpfd > maxfd)
maxfd = dhcpfd;
}
#ifdef HAVE_PSELECT
if (pselect(maxfd+1, &rset, NULL, NULL, NULL, &sigmask) < 0)
FD_ZERO(&rset); /* rset otherwise undefined after error */
@@ -342,7 +343,7 @@ int main (int argc, char **argv)
}
first_loop = 0;
now = time(NULL);
now = dnsmasq_time(uptime_fd);
/* Check for changes to resolv files once per second max. */
if (last == 0 || difftime(now, last) > 1.0)
@@ -391,62 +392,28 @@ int main (int argc, char **argv)
last_server = reply_query(serverfdp->fd, options, packet, now,
dnamebuff, last_server, bogus_addr);
for (dhcp_tmp = dhcp; dhcp_tmp; dhcp_tmp = dhcp_tmp->next)
if (FD_ISSET(dhcp_tmp->fd, &rset))
dhcp_packet(dhcp_tmp, packet, dhcp_options, dhcp_configs,
now, dnamebuff, domain_suffix, dhcp_file,
dhcp_sname, dhcp_next_server);
if (dhcp && FD_ISSET(dhcpfd, &rset))
dhcp_packet(dhcp, packet, dhcp_options, dhcp_configs,
now, dnamebuff, domain_suffix, dhcp_file,
dhcp_sname, dhcp_next_server, dhcpfd, dhcp_raw_fd,
if_names, if_addrs, if_except);
for (iface = interfaces; iface; iface = iface->next)
{
if (FD_ISSET(iface->fd, &rset))
{
/* request packet, deal with query */
union mysockaddr udpaddr;
socklen_t udplen = sizeof(udpaddr);
HEADER *header = (HEADER *)packet;
int m, n = recvfrom(iface->fd, packet, PACKETSZ, 0, &udpaddr.sa, &udplen);
udpaddr.sa.sa_family = iface->addr.sa.sa_family;
#ifdef HAVE_IPV6
if (udpaddr.sa.sa_family == AF_INET6)
udpaddr.in6.sin6_flowinfo = htonl(0);
#endif
if (n >= (int)sizeof(HEADER) && !header->qr)
{
if (extract_request(header, (unsigned int)n, dnamebuff))
{
if (udpaddr.sa.sa_family == AF_INET)
log_query(F_QUERY | F_IPV4 | F_FORWARD, dnamebuff,
(struct all_addr *)&udpaddr.in.sin_addr);
#ifdef HAVE_IPV6
else
log_query(F_QUERY | F_IPV6 | F_FORWARD, dnamebuff,
(struct all_addr *)&udpaddr.in6.sin6_addr);
#endif
}
m = answer_request (header, ((char *) header) + PACKETSZ, (unsigned int)n,
mxname, mxtarget, options, now, local_ttl, dnamebuff);
if (m >= 1)
{
/* answered from cache, send reply */
sendto(iface->fd, (char *)header, m, 0,
&udpaddr.sa, sa_len(&udpaddr));
}
else
{
/* cannot answer from cache, send on to real nameserver */
last_server = forward_query(iface->fd, &udpaddr, header, n,
options, dnamebuff, servers,
last_server, now, local_ttl);
}
}
}
}
for (listener = listeners; listener; listener = listener->next)
if (FD_ISSET(listener->fd, &rset))
last_server = receive_query(listener, packet,
mxname, mxtarget, options, now, local_ttl, dnamebuff,
if_names, if_addrs, if_except, last_server, servers);
}
syslog(LOG_INFO, "exiting on receipt of SIGTERM");
#ifdef HAVE_BROKEN_RTC
if (dhcp)
lease_update_file(1, now);
#endif
if (leasefd != -1)
close(leasefd);
return 0;
}