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import of dnsmasq-2.34.tar.gz

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This commit is contained in:
Simon Kelley
2006-10-16 20:04:18 +01:00
parent 208b65c5cf
commit 1697269ce7
33 changed files with 3660 additions and 2711 deletions
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262
src/dnsmasq.c
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@@ -24,6 +24,9 @@ static char *compile_opts =
#ifdef HAVE_BROKEN_RTC
"no-RTC "
#endif
#ifdef NO_FORK
"no-MMU "
#endif
#ifndef HAVE_ISC_READER
"no-"
#endif
@@ -40,7 +43,7 @@ static char *compile_opts =
static pid_t pid;
static int pipewrite;
static int set_dns_listeners(struct daemon *daemon, fd_set *set, int maxfd);
static int set_dns_listeners(struct daemon *daemon, time_t now, fd_set *set, int *maxfdp);
static void check_dns_listeners(struct daemon *daemon, fd_set *set, time_t now);
static void sig_handler(int sig);
@@ -195,62 +198,18 @@ int main (int argc, char **argv)
/* prime the pipe to load stuff first time. */
sig = SIGHUP;
write(pipewrite, &sig, 1);
if (daemon->options & OPT_DEBUG)
{
#ifdef LOG_PERROR
openlog("dnsmasq", LOG_PERROR, daemon->log_fac);
#else
openlog("dnsmasq", 0, daemon->log_fac);
#endif
#ifdef HAVE_LINUX_NETWORK
prctl(PR_SET_DUMPABLE, 1);
#endif
}
else
if (!(daemon->options & OPT_DEBUG))
{
FILE *pidfile;
struct passwd *ent_pw = daemon->username ? getpwnam(daemon->username) : NULL;
fd_set test_set;
int maxfd, i;
int maxfd = -1, i;
int nullfd = open("/dev/null", O_RDWR);
#ifdef HAVE_LINUX_NETWORK
cap_user_header_t hdr = NULL;
cap_user_data_t data = NULL;
/* On linux, we keep CAP_NETADMIN (for ARP-injection) and
CAP_NET_RAW (for icmp) if we're doing dhcp */
if (ent_pw && ent_pw->pw_uid != 0)
{
hdr = safe_malloc(sizeof(*hdr));
data = safe_malloc(sizeof(*data));
hdr->version = _LINUX_CAPABILITY_VERSION;
hdr->pid = 0; /* this process */
data->effective = data->permitted = data->inheritable =
(1 << CAP_NET_ADMIN) | (1 << CAP_NET_RAW) |
(1 << CAP_SETGID) | (1 << CAP_SETUID);
/* Tell kernel to not clear capabilities when dropping root */
if (capset(hdr, data) == -1 || prctl(PR_SET_KEEPCAPS, 1) == -1)
{
bad_capabilities = errno;
ent_pw = NULL;
}
}
#endif
FD_ZERO(&test_set);
maxfd = set_dns_listeners(daemon, &test_set, -1);
#ifdef HAVE_DBUS
maxfd = set_dbus_listeners(daemon, maxfd, &test_set, &test_set, &test_set);
#endif
/* The following code "daemonizes" the process.
See Stevens section 12.4 */
#ifndef NO_FORK
#ifndef NO_FORK
if (!(daemon->options & OPT_NO_FORK))
{
if (fork() != 0 )
@@ -274,7 +233,12 @@ int main (int argc, char **argv)
}
umask(0);
FD_ZERO(&test_set);
set_dns_listeners(daemon, now, &test_set, &maxfd);
#ifdef HAVE_DBUS
set_dbus_listeners(daemon, &maxfd, &test_set, &test_set, &test_set);
#endif
for (i=0; i<64; i++)
{
if (i == piperead || i == pipewrite)
@@ -303,7 +267,16 @@ int main (int argc, char **argv)
else
close(i);
}
}
/* if we are to run scripts, we need to fork a helper before dropping root. */
daemon->helperfd = create_helper(daemon);
if (!(daemon->options & OPT_DEBUG))
{
/* UID changing, etc */
struct passwd *ent_pw = daemon->username ? getpwnam(daemon->username) : NULL;
if (daemon->groupname || ent_pw)
{
gid_t dummy;
@@ -318,32 +291,55 @@ int main (int argc, char **argv)
setgid(gp->gr_gid);
}
}
if (ent_pw && ent_pw->pw_uid != 0)
{
/* finally drop root */
setuid(ent_pw->pw_uid);
{
#ifdef HAVE_LINUX_NETWORK
data->effective = data->permitted =
(1 << CAP_NET_ADMIN) | (1 << CAP_NET_RAW);
data->inheritable = 0;
/* On linux, we keep CAP_NETADMIN (for ARP-injection) and
CAP_NET_RAW (for icmp) if we're doing dhcp */
cap_user_header_t hdr = safe_malloc(sizeof(*hdr));
cap_user_data_t data = safe_malloc(sizeof(*data));
hdr->version = _LINUX_CAPABILITY_VERSION;
hdr->pid = 0; /* this process */
data->effective = data->permitted = data->inheritable =
(1 << CAP_NET_ADMIN) | (1 << CAP_NET_RAW) |
(1 << CAP_SETGID) | (1 << CAP_SETUID);
/* lose the setuid and setgid capbilities */
capset(hdr, data);
/* Tell kernel to not clear capabilities when dropping root */
if (capset(hdr, data) == -1 || prctl(PR_SET_KEEPCAPS, 1) == -1)
bad_capabilities = errno;
else
#endif
{
/* finally drop root */
setuid(ent_pw->pw_uid);
#ifdef HAVE_LINUX_NETWORK
data->effective = data->permitted =
(1 << CAP_NET_ADMIN) | (1 << CAP_NET_RAW);
data->inheritable = 0;
/* lose the setuid and setgid capbilities */
capset(hdr, data);
#endif
}
}
openlog("dnsmasq", LOG_PID, daemon->log_fac);
}
log_start(daemon);
#ifdef HAVE_LINUX_NETWORK
if (daemon->options & OPT_DEBUG)
prctl(PR_SET_DUMPABLE, 1);
#endif
if (daemon->cachesize != 0)
syslog(LOG_INFO, _("started, version %s cachesize %d"), VERSION, daemon->cachesize);
else
syslog(LOG_INFO, _("started, version %s cache disabled"), VERSION);
syslog(LOG_INFO, _("compile time options: %s"), compile_opts);
#ifdef HAVE_DBUS
if (daemon->options & OPT_DBUS)
{
@@ -399,53 +395,59 @@ int main (int argc, char **argv)
pid = getpid();
/* Start lease-change script */
if (daemon->dhcp)
lease_collect(daemon);
while (1)
{
int maxfd;
int maxfd = -1;
struct timeval t, *tp = NULL;
fd_set rset, wset, eset;
t.tv_sec = 0; /* no warning */
FD_ZERO(&rset);
FD_ZERO(&wset);
FD_ZERO(&eset);
maxfd = set_dns_listeners(daemon, &rset, -1);
/* if we are out of resources, find how long we have to wait
for some to come free, we'll loop around then and restart
listening for queries */
if ((t.tv_sec = set_dns_listeners(daemon, now, &rset, &maxfd)) != 0)
{
t.tv_usec = 0;
tp = &t;
}
#ifdef HAVE_DBUS
/* Whilst polling for the dbus, wake every quarter second */
if ((daemon->options & OPT_DBUS) && !daemon->dbus)
{
t.tv_sec = 0;
t.tv_usec = 250000;
tp = &t;
tp->tv_sec = 0;
tp->tv_usec = 250000;
}
maxfd = set_dbus_listeners(daemon, maxfd, &rset, &wset, &eset);
set_dbus_listeners(daemon, &maxfd, &rset, &wset, &eset);
#endif
if (daemon->dhcp)
{
FD_SET(daemon->dhcpfd, &rset);
if (daemon->dhcpfd > maxfd)
maxfd = daemon->dhcpfd;
bump_maxfd(daemon->dhcpfd, &maxfd);
}
#ifdef HAVE_LINUX_NETWORK
FD_SET(daemon->netlinkfd, &rset);
if (daemon->netlinkfd > maxfd)
maxfd = daemon->netlinkfd;
bump_maxfd(daemon->netlinkfd, &maxfd);
#endif
FD_SET(piperead, &rset);
if (piperead > maxfd)
maxfd = piperead;
bump_maxfd(piperead, &maxfd);
while (helper_buf_empty() && do_script_run(daemon));
if (!helper_buf_empty())
{
FD_SET(daemon->helperfd, &wset);
bump_maxfd(daemon->helperfd, &maxfd);
}
if (select(maxfd+1, &rset, &wset, &eset, tp) < 0)
{
/* otherwise undefined after error */
@@ -502,6 +504,8 @@ int main (int argc, char **argv)
syslog(LOG_INFO, _("reading %s"), latest->name);
warned = 0;
check_servers(daemon);
if (daemon->options & OPT_RELOAD)
cache_reload(daemon->options, daemon->namebuff, daemon->domain_suffix, daemon->addn_hosts);
}
else
{
@@ -541,22 +545,33 @@ int main (int argc, char **argv)
{
lease_prune(NULL, now);
lease_update_file(daemon, now);
lease_collect(daemon);
}
break;
case SIGTERM:
{
int i;
syslog(LOG_INFO, _("exiting on receipt of SIGTERM"));
/* Knock all our children on the head. */
for (i = 0; i < MAX_PROCS; i++)
if (daemon->tcp_pids[i] != 0)
kill(daemon->tcp_pids[i], SIGALRM);
/* handle pending lease transitions */
if (daemon->helperfd != -1)
{
/* block in writes until all done */
if ((i = fcntl(daemon->helperfd, F_GETFL)) != -1)
fcntl(daemon->helperfd, F_SETFL, i & ~O_NONBLOCK);
do {
helper_write(daemon);
} while (!helper_buf_empty() || do_script_run(daemon));
close(daemon->helperfd);
}
if (daemon->lease_stream)
fclose(daemon->lease_stream);
syslog(LOG_INFO, _("exiting on receipt of SIGTERM"));
exit(0);
}
@@ -568,22 +583,13 @@ int main (int argc, char **argv)
whose pid != script_pid are TCP server threads. */
while ((p = waitpid(-1, NULL, WNOHANG)) > 0)
{
if (p == daemon->script_pid)
{
daemon->script_pid = 0;
lease_collect(daemon);
}
else
{
int i;
for (i = 0 ; i < MAX_PROCS; i++)
if (daemon->tcp_pids[i] == p)
{
daemon->tcp_pids[i] = 0;
daemon->num_kids--;
break;
}
}
int i;
for (i = 0 ; i < MAX_PROCS; i++)
if (daemon->tcp_pids[i] == p)
{
daemon->tcp_pids[i] = 0;
break;
}
}
break;
}
@@ -611,6 +617,9 @@ int main (int argc, char **argv)
if (daemon->dhcp && FD_ISSET(daemon->dhcpfd, &rset))
dhcp_packet(daemon, now);
if (daemon->helperfd != -1 && FD_ISSET(daemon->helperfd, &wset))
helper_write(daemon);
}
}
@@ -618,7 +627,8 @@ static void sig_handler(int sig)
{
if (pid == 0)
{
/* ignore anything other than TERM during startup */
/* ignore anything other than TERM during startup
and in helper proc. (helper ignore TERM too) */
if (sig == SIGTERM)
exit(0);
}
@@ -632,7 +642,7 @@ static void sig_handler(int sig)
}
else
{
/* alarm is used to kill children after a fixed time. */
/* alarm is used to kill TCP children after a fixed time. */
if (sig == SIGALRM)
_exit(0);
}
@@ -653,29 +663,42 @@ void clear_cache_and_reload(struct daemon *daemon, time_t now)
}
}
static int set_dns_listeners(struct daemon *daemon, fd_set *set, int maxfd)
static int set_dns_listeners(struct daemon *daemon, time_t now, fd_set *set, int *maxfdp)
{
struct serverfd *serverfdp;
struct listener *listener;
int wait, i;
/* will we be able to get memory? */
get_new_frec(daemon, now, &wait);
for (serverfdp = daemon->sfds; serverfdp; serverfdp = serverfdp->next)
{
FD_SET(serverfdp->fd, set);
if (serverfdp->fd > maxfd)
maxfd = serverfdp->fd;
bump_maxfd(serverfdp->fd, maxfdp);
}
for (listener = daemon->listeners; listener; listener = listener->next)
{
FD_SET(listener->fd, set);
if (listener->fd > maxfd)
maxfd = listener->fd;
FD_SET(listener->tcpfd, set);
if (listener->tcpfd > maxfd)
maxfd = listener->tcpfd;
/* only listen for queries if we have resources */
if (wait == 0)
{
FD_SET(listener->fd, set);
bump_maxfd(listener->fd, maxfdp);
}
/* death of a child goes through the select loop, so
we don't need to explicitly arrange to wake up here */
for (i = 0; i < MAX_PROCS; i++)
if (daemon->tcp_pids[i] == 0)
{
FD_SET(listener->tcpfd, set);
bump_maxfd(listener->tcpfd, maxfdp);
break;
}
}
return maxfd;
return wait;
}
static void check_dns_listeners(struct daemon *daemon, fd_set *set, time_t now)
@@ -723,7 +746,7 @@ static void check_dns_listeners(struct daemon *daemon, fd_set *set, time_t now)
break;
}
if ((daemon->num_kids >= MAX_PROCS) || !iface)
if (!iface)
{
shutdown(confd, SHUT_RDWR);
close(confd);
@@ -740,7 +763,6 @@ static void check_dns_listeners(struct daemon *daemon, fd_set *set, time_t now)
daemon->tcp_pids[i] = p;
break;
}
daemon->num_kids++;
}
close(confd);
}
@@ -869,7 +891,7 @@ int icmp_ping(struct daemon *daemon, struct in_addr addr)
struct timeval tv;
fd_set rset;
struct sockaddr_in faddr;
int maxfd;
int maxfd = fd;
socklen_t len = sizeof(faddr);
tv.tv_usec = 250000;
@@ -877,7 +899,7 @@ int icmp_ping(struct daemon *daemon, struct in_addr addr)
FD_ZERO(&rset);
FD_SET(fd, &rset);
maxfd = set_dns_listeners(daemon, &rset, fd);
set_dns_listeners(daemon, now, &rset, &maxfd);
if (select(maxfd+1, &rset, NULL, NULL, &tv) < 0)
FD_ZERO(&rset);