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import of dnsmasq-2.10.tar.gz

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This commit is contained in:
Simon Kelley
2004-07-27 20:28:58 +01:00
parent de37951cf4
commit feba5c1d25
21 changed files with 1968 additions and 602 deletions
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207
src/dnsmasq.c
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@@ -10,13 +10,11 @@
GNU General Public License for more details.
*/
/* See RFC1035 for details of the protocol this code talks. */
/* Author's email: simon@thekelleys.org.uk */
#include "dnsmasq.h"
static int sigterm, sighup, sigusr1, sigalarm;
static int sigterm, sighup, sigusr1, sigalarm, num_kids, in_child;
static void sig_handler(int sig)
{
@@ -27,7 +25,22 @@ static void sig_handler(int sig)
else if (sig == SIGUSR1)
sigusr1 = 1;
else if (sig == SIGALRM)
sigalarm = 1;
{
/* alarm is used to kill children after a fixed time. */
if (in_child)
exit(0);
else
sigalarm = 1;
}
else if (sig == SIGCHLD)
{
/* See Stevens 5.10 */
pid_t pid;
int stat;
while ((pid = waitpid(-1, &stat, WNOHANG)) > 0)
num_kids--;
}
}
int main (int argc, char **argv)
@@ -35,6 +48,7 @@ int main (int argc, char **argv)
int cachesize = CACHESIZ;
int port = NAMESERVER_PORT;
int maxleases = MAXLEASES;
unsigned short edns_pktsz = EDNS_PKTSZ;
int query_port = 0;
int first_loop = 1;
int bind_fallback = 0;
@@ -82,6 +96,8 @@ int main (int argc, char **argv)
#else
sigalarm = 0; /* or not */
#endif
num_kids = 0;
in_child = 0;
sigact.sa_handler = sig_handler;
sigact.sa_flags = 0;
@@ -90,6 +106,11 @@ int main (int argc, char **argv)
sigaction(SIGHUP, &sigact, NULL);
sigaction(SIGTERM, &sigact, NULL);
sigaction(SIGALRM, &sigact, NULL);
sigaction(SIGCHLD, &sigact, NULL);
/* ignore SIGPIPE */
sigact.sa_handler = SIG_IGN;
sigaction(SIGPIPE, &sigact, NULL);
/* now block all the signals, they stay that way except
during the call to pselect */
@@ -97,6 +118,7 @@ int main (int argc, char **argv)
sigaddset(&sigact.sa_mask, SIGTERM);
sigaddset(&sigact.sa_mask, SIGHUP);
sigaddset(&sigact.sa_mask, SIGALRM);
sigaddset(&sigact.sa_mask, SIGCHLD);
sigprocmask(SIG_BLOCK, &sigact.sa_mask, &sigmask);
/* These get allocated here to avoid overflowing the small stack
@@ -104,7 +126,6 @@ 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);
packet = safe_malloc(DNSMASQ_PACKETSZ);
dhcp_next_server.s_addr = 0;
options = read_opts(argc, argv, dnamebuff, &resolv, &mxnames, &mxtarget, &lease_file,
@@ -113,7 +134,11 @@ int main (int argc, char **argv)
&serv_addrs, &cachesize, &port, &query_port, &local_ttl, &addn_hosts,
&dhcp, &dhcp_configs, &dhcp_options, &dhcp_vendors,
&dhcp_file, &dhcp_sname, &dhcp_next_server, &maxleases, &min_leasetime,
&doctors);
&doctors, &edns_pktsz);
if (edns_pktsz < PACKETSZ)
edns_pktsz = PACKETSZ;
packet = safe_malloc(edns_pktsz > DNSMASQ_PACKETSZ ? edns_pktsz : DNSMASQ_PACKETSZ);
if (!lease_file)
{
@@ -136,7 +161,7 @@ int main (int argc, char **argv)
if (options & OPT_NOWILD)
{
struct iname *if_tmp;
listeners = create_bound_listeners(interfaces);
listeners = create_bound_listeners(interfaces, port);
for (if_tmp = if_names; if_tmp; if_tmp = if_tmp->next)
if (if_tmp->name && !if_tmp->used)
@@ -184,6 +209,31 @@ int main (int argc, char **argv)
dhcp_init(&dhcpfd, &dhcp_raw_fd);
leasefd = lease_init(lease_file, domain_suffix, dnamebuff, packet, now, maxleases);
}
/* If query_port is set then create a socket now, before dumping root
for use to access nameservers without more specific source addresses.
This allows query_port to be a low port */
if (query_port)
{
union mysockaddr addr;
addr.in.sin_family = AF_INET;
addr.in.sin_addr.s_addr = INADDR_ANY;
addr.in.sin_port = htons(query_port);
#ifdef HAVE_SOCKADDR_SA_LEN
addr.in.sin_len = sizeof(struct sockaddr_in);
#endif
allocate_sfd(&addr, &sfds);
#ifdef HAVE_IPV6
addr.in6.sin6_family = AF_INET6;
addr.in6.sin6_addr = in6addr_any;
addr.in6.sin6_port = htons(query_port);
addr.in6.sin6_flowinfo = htonl(0);
#ifdef HAVE_SOCKADDR_SA_LEN
addr.in6.sin6_len = sizeof(struct sockaddr_in6);
#endif
allocate_sfd(&addr, &sfds);
#endif
}
setbuf(stdout, NULL);
@@ -221,8 +271,12 @@ int main (int argc, char **argv)
for (i=0; i<64; i++)
{
for (listener = listeners; listener; listener = listener->next)
if (listener->fd == i)
break;
{
if (listener->fd == i)
break;
if (listener->tcpfd == i)
break;
}
if (listener)
continue;
@@ -232,6 +286,12 @@ int main (int argc, char **argv)
i == dhcp_raw_fd)
continue;
for (serverfdp = sfds; serverfdp; serverfdp = serverfdp->next)
if (serverfdp->fd == i)
break;
if (serverfdp)
continue;
close(i);
}
@@ -256,13 +316,13 @@ int main (int argc, char **argv)
DNSMASQ_LOG_OPT(options & OPT_DEBUG),
DNSMASQ_LOG_FAC(options & OPT_DEBUG));
if (cachesize)
if (cachesize != 0)
syslog(LOG_INFO, "started, version %s cachesize %d", VERSION, cachesize);
else
syslog(LOG_INFO, "started, version %s cache disabled", VERSION);
if (bind_fallback)
syslog(LOG_WARNING, "setting --bind-interfaces option because if OS limitations");
syslog(LOG_WARNING, "setting --bind-interfaces option because of OS limitations");
for (dhcp_tmp = dhcp; dhcp_tmp; dhcp_tmp = dhcp_tmp->next)
{
@@ -270,7 +330,15 @@ int main (int argc, char **argv)
if (dhcp_tmp->lease_time == 0)
sprintf(packet, "infinite");
else
sprintf(packet, "%ds", (int)dhcp_tmp->lease_time);
{
unsigned int x, p = 0, t = (unsigned int)dhcp_tmp->lease_time;
if ((x = t/3600))
p += sprintf(&packet[p], "%dh", x);
if ((x = (t/60)%60))
p += sprintf(&packet[p], "%dm", x);
if ((x = t%60))
p += sprintf(&packet[p], "%ds", x);
}
syslog(LOG_INFO,
dhcp_tmp->start.s_addr == dhcp_tmp->end.s_addr ?
"DHCP, static leases only on %.0s%s, lease time %s" :
@@ -282,9 +350,9 @@ int main (int argc, char **argv)
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");
if (!(options & OPT_DEBUG) && (getuid() == 0 || geteuid() == 0))
syslog(LOG_WARNING, "running as root");
servers = check_servers(serv_addrs, interfaces, &sfds);
last_server = NULL;
@@ -350,6 +418,9 @@ int main (int argc, char **argv)
FD_SET(listener->fd, &rset);
if (listener->fd > maxfd)
maxfd = listener->fd;
FD_SET(listener->tcpfd, &rset);
if (listener->tcpfd > maxfd)
maxfd = listener->tcpfd;
}
if (dhcp)
@@ -428,7 +499,8 @@ int main (int argc, char **argv)
for (serverfdp = sfds; serverfdp; serverfdp = serverfdp->next)
if (FD_ISSET(serverfdp->fd, &rset))
last_server = reply_query(serverfdp, options, packet, now,
dnamebuff, servers, last_server, bogus_addr, doctors);
dnamebuff, servers, last_server,
bogus_addr, doctors, edns_pktsz);
if (dhcp && FD_ISSET(dhcpfd, &rset))
dhcp_packet(dhcp, packet, dhcp_options, dhcp_configs, dhcp_vendors,
@@ -437,10 +509,105 @@ int main (int argc, char **argv)
if_names, if_addrs, if_except);
for (listener = listeners; listener; listener = listener->next)
if (FD_ISSET(listener->fd, &rset))
last_server = receive_query(listener, packet,
mxnames, mxtarget, options, now, local_ttl, dnamebuff,
if_names, if_addrs, if_except, last_server, servers);
{
if (FD_ISSET(listener->fd, &rset))
last_server = receive_query(listener, packet,
mxnames, mxtarget, options, now, local_ttl, dnamebuff,
if_names, if_addrs, if_except, last_server, servers, edns_pktsz);
if (FD_ISSET(listener->tcpfd, &rset))
{
int confd;
while((confd = accept(listener->tcpfd, NULL, NULL)) == -1 && errno == EINTR);
if (confd != -1)
{
int match = 1;
if (!(options & OPT_NOWILD))
{
/* Check for allowed interfaces when binding the wildcard address */
/* Don't know how to get interface of a connection, so we have to
check by address. This will break when interfaces change address */
union mysockaddr tcp_addr;
socklen_t tcp_len = sizeof(union mysockaddr);
struct iname *tmp;
if (getsockname(confd, (struct sockaddr *)&tcp_addr, &tcp_len) != -1)
{
#ifdef HAVE_IPV6
if (tcp_addr.sa.sa_family == AF_INET6)
tcp_addr.in6.sin6_flowinfo = htonl(0);
#endif
for (match = 1, tmp = if_except; tmp; tmp = tmp->next)
if (sockaddr_isequal(&tmp->addr, &tcp_addr))
match = 0;
if (match && (if_names || if_addrs))
{
match = 0;
for (tmp = if_names; tmp; tmp = tmp->next)
if (sockaddr_isequal(&tmp->addr, &tcp_addr))
match = 1;
for (tmp = if_addrs; tmp; tmp = tmp->next)
if (sockaddr_isequal(&tmp->addr, &tcp_addr))
match = 1;
}
}
}
if (!match || (num_kids >= MAX_PROCS))
close(confd);
else if (!(options & OPT_DEBUG) && fork())
{
num_kids++;
close(confd);
}
else
{
char *buff;
struct server *s;
int flags;
/* Arrange for SIGALARM after CHILD_LIFETIME seconds to
terminate the process. */
if (!(options & OPT_DEBUG))
{
sigemptyset(&sigact.sa_mask);
sigaddset(&sigact.sa_mask, SIGALRM);
sigprocmask(SIG_UNBLOCK, &sigact.sa_mask, NULL);
alarm(CHILD_LIFETIME);
in_child = 1;
}
/* start with no upstream connections. */
for (s = servers; s; s = s->next)
s->tcpfd = -1;
/* The connected socket inherits non-blocking
attribute from the listening socket.
Reset that here. */
if ((flags = fcntl(confd, F_GETFL, 0)) != -1)
fcntl(confd, F_SETFL, flags & ~O_NONBLOCK);
buff = tcp_request(confd, mxnames, mxtarget, options, now,
local_ttl, dnamebuff, last_server, servers,
bogus_addr, doctors, edns_pktsz);
if (!(options & OPT_DEBUG))
exit(0);
close(confd);
if (buff)
free(buff);
for (s = servers; s; s = s->next)
if (s->tcpfd != -1)
close(s->tcpfd);
}
}
}
}
}
syslog(LOG_INFO, "exiting on receipt of SIGTERM");