WIP dnsupdatednsupdate

1 files changed, 217 insertions, 0 deletions

diff --git a/src/dnsupdate.c b/src/dnsupdate.c
new file mode 100644
index 0000000..e8550a6
--- /dev/null
+++ b/src/dnsupdate.c
@@ -0,0 +1,217 @@
+#include <arpa/inet.h>
+#include <fcntl.h>
+#include <syslog.h>
+#include <unistd.h>
+#include <libubox/uloop.h>
+#include "odhcpd.h"
+
+#define READ_END 0
+#define WRITE_END 1
+
+static void update_cb(struct uloop_fd *u, unsigned int events);
+static void update_proc_cb(struct uloop_process *c, int ret);
+static void update_time_cb(struct uloop_timeout *t);
+
+static int dns_start();
+static int dns_update_init();
+static ssize_t dns_write(const char *buf, size_t count);
+
+static struct uloop_fd update_in = { .fd = -1, .cb = update_cb };
+static struct uloop_fd update_err = { .fd = -1, .cb = update_cb };
+static struct uloop_process update_proc = { .cb = update_proc_cb };
+static int update_pipes[3][2] = {{-1, -1}, {-1, -1}, {-1, -1}};
+static struct uloop_timeout update_time = { .cb = update_time_cb };
+
+static void update_time_cb(struct uloop_timeout *t)
+{
+	const char CMD_QUIT[] = "quit\n";
+	syslog(LOG_ERR, "update_time");
+	if (update_pipes[1][WRITE_END] < 0) {
+		return;
+	}
+	dns_write(CMD_QUIT, sizeof(CMD_QUIT));
+}
+
+static void update_cb(struct uloop_fd *u, unsigned int events)
+{
+	syslog(LOG_ERR, "update_cb: %d %d", u->fd, events);
+
+//	if (events & ULOOP_READ) {
+		char buf[512];
+		int len = 0;
+		if ((len = read(u->fd, buf, sizeof(buf)-1)) > 0) {
+			buf[len] = 0;
+			syslog(LOG_ERR, "update_cb: read '%s'", buf);
+		}
+//	}
+	syslog(LOG_ERR, "update_cb: read done");
+}
+
+
+static void update_proc_cb(struct uloop_process *c, int ret)
+{
+	syslog(LOG_ERR, "update_cb: process exit: %d", ret);
+	uloop_timeout_cancel(&update_time);
+	c->pid = 0;
+	uloop_fd_delete(&update_in);
+	update_in.fd = -1;
+	uloop_fd_delete(&update_err);
+	update_err.fd = -1;
+	close(update_pipes[0][READ_END]);
+	close(update_pipes[1][WRITE_END]);
+	close(update_pipes[2][READ_END]);
+	update_pipes[0][READ_END] = -1;
+	update_pipes[1][WRITE_END] = -1;
+	update_pipes[2][READ_END] = -1;
+}
+
+static ssize_t dns_write(const char *buf, size_t count)
+{
+	if (update_pipes[1][WRITE_END] < 0) {
+		if (dns_start() < 0)
+			return -1;
+	}
+
+	uloop_timeout_set(&update_time, 10 * 1000);
+	return write(update_pipes[1][WRITE_END], buf, count);
+}
+
+int dns_update_rr(const char *hostname, int family, const void *addr)
+{
+	if (!config.nsupdate_domain) {
+		return 0;
+	}
+
+	if (!hostname) {
+		syslog(LOG_ERR, "update_cb: no hostname");
+		return 0;
+	}
+
+	dns_update_init();
+
+	char tmp_addr[INET6_ADDRSTRLEN];
+	inet_ntop(family, addr, tmp_addr, sizeof(tmp_addr));
+
+	char buf[512]="";
+	int res = snprintf(buf, sizeof(buf), "add %s.%s. 3600 %s %s\n", hostname, config.nsupdate_domain, family==AF_INET6?"AAAA":"A", tmp_addr);
+	// build_nsupdate(name, 'dhcid', build_dhcid(TYPE_HWID, mac))
+	// build_nsupdate(name, 'dhcid', build_dhcid(TYPE_DUID, duid))
+
+	syslog(LOG_ERR, "dns_update_rr: buf=%s", buf);
+
+	if (res > 0 && res < (int)sizeof(buf)) {
+		res = dns_write(buf, strlen(buf));
+		syslog(LOG_ERR, "dns_update_rr: write %d %zd", res, strlen(buf));
+		syslog(LOG_ERR, "dns_update_rr: hostname=%s addr=%s", hostname, tmp_addr);
+	}
+	return 0;
+}
+
+int dns_update_finish()
+{
+	const char CMD[] = "send\n";
+	int res = dns_write(CMD, strlen(CMD));
+	syslog(LOG_ERR, "dns_update_finish: write %d %zd", res, strlen(CMD));
+	return res;
+}
+
+int dns_reload()
+{
+	return 0;
+}
+
+static int dns_update_init()
+{
+	struct {
+		const char *name;
+		const char *value;
+	} params[] = {
+		{ "key", config.nsupdate_key },
+		{ "server", config.nsupdate_server },
+		{ "zone", config.nsupdate_zone },
+		{ NULL, NULL },
+	};
+
+	for (int i = 0; params[i].name; i++) {
+
+		if (!params[i].value)
+			continue;
+
+		char buf[512];
+		int len = snprintf(buf, sizeof(buf), "%s %s\n",
+				   params[i].name, params[i].value);
+
+		if (len < 0 || len > (int)sizeof(buf))
+			continue;
+
+		syslog(LOG_ERR, "dns_reload: %s=%s", params[i].name, params[i].value);
+		int res = dns_write(buf, len);
+		syslog(LOG_ERR, "dns_reload: write %d %d", res, len);
+	}
+
+	return 0;
+}
+
+int dns_init()
+{
+	syslog(LOG_ERR, "dns_init");
+	return -1;
+}
+
+static int dns_start()
+{
+	/* if (update_pipes[0] > -1) */
+	/* 	close(update_pipes[0]); */
+
+	/* if (update_pipes[1] > -1) */
+	/* 	close(update_pipes[1]); */
+
+	for (int i = 0; i < 3; i++) {
+		if (pipe2(update_pipes[i], 0) < 0) {
+			syslog(LOG_ERR, "dns_init: pipe2 failed");
+			return -1;
+		}
+	}
+
+	int pid = fork();
+
+	switch (pid) {
+	case 0:
+		/* child */
+		syslog(LOG_ERR, "dns_init: child");
+		dup2(update_pipes[0][WRITE_END], STDOUT_FILENO);
+		dup2(update_pipes[1][READ_END], STDIN_FILENO);
+		dup2(update_pipes[2][WRITE_END], STDERR_FILENO);
+		close(update_pipes[0][READ_END]);
+		close(update_pipes[1][WRITE_END]);
+		close(update_pipes[2][READ_END]);
+
+		char *argv[2] = {"/root/knsupdate.sh", NULL};
+		execv(argv[0], argv);
+		syslog(LOG_ERR, "dns_init: exec error?");
+		return 0;
+	case -1:
+		/* error returned in parent. */
+		syslog(LOG_ERR, "dns_init: failed");
+		return -1;
+	default:
+		/* parent */
+		break;
+	}
+
+	syslog(LOG_ERR, "dns_init: parent '%d'", pid);
+	update_in.fd = update_pipes[0][READ_END];
+	update_err.fd = update_pipes[2][READ_END];
+	close(update_pipes[0][WRITE_END]);
+	close(update_pipes[1][READ_END]);
+	close(update_pipes[2][WRITE_END]);
+	update_pipes[0][WRITE_END] = -1;
+	update_pipes[1][READ_END] = -1;
+	update_pipes[2][WRITE_END] = -1;
+	uloop_fd_add(&update_in, ULOOP_READ | ULOOP_BLOCKING);
+	uloop_fd_add(&update_err, ULOOP_READ | ULOOP_BLOCKING);
+	update_proc.pid = pid;
+	uloop_process_add(&update_proc);
+	//dns_reload();
+	return 0;
+}