1 files changed, 116 insertions, 0 deletions
diff --git a/cmd/lwip/dns.c b/cmd/lwip/dns.c
new file mode 100644
index 00000000000..b5fccc7433e
--- /dev/null
+++ b/cmd/lwip/dns.c
@@ -0,0 +1,116 @@
+// SPDX-License-Identifier: GPL-2.0+
+/* Copyright (C) 2024 Linaro Ltd. */
+
+#include <command.h>
+#include <console.h>
+#include <env.h>
+#include <lwip/dns.h>
+#include <lwip/timeouts.h>
+#include <net.h>
+#include <time.h>
+
+U_BOOT_CMD(dns, 3, 1, do_dns, "lookup the IP of a hostname",
+	   "hostname [envvar]");
+
+#define DNS_RESEND_MS 1000
+#define DNS_TIMEOUT_MS 10000
+
+struct dns_cb_arg {
+	ip_addr_t host_ipaddr;
+	const char *var;
+	bool done;
+};
+
+static void do_dns_tmr(void *arg)
+{
+	dns_tmr();
+}
+
+static void dns_cb(const char *name, const ip_addr_t *ipaddr, void *arg)
+{
+	struct dns_cb_arg *dns_cb_arg = arg;
+	char *ipstr = ip4addr_ntoa(ipaddr);
+
+	dns_cb_arg->done = true;
+
+	if (!ipaddr) {
+		printf("DNS: host not found\n");
+		dns_cb_arg->host_ipaddr.addr = 0;
+		return;
+	}
+
+	dns_cb_arg->host_ipaddr.addr = ipaddr->addr;
+
+	if (dns_cb_arg->var)
+		env_set(dns_cb_arg->var, ipstr);
+}
+
+static int dns_loop(struct udevice *udev, const char *name, const char *var)
+{
+	struct dns_cb_arg dns_cb_arg = { };
+	struct netif *netif;
+	ip_addr_t ipaddr;
+	ulong start;
+	int ret;
+
+	dns_cb_arg.var = var;
+
+	netif = net_lwip_new_netif(udev);
+	if (!netif)
+		return CMD_RET_FAILURE;
+
+	if (net_lwip_dns_init()) {
+		net_lwip_remove_netif(netif);
+		return CMD_RET_FAILURE;
+	}
+
+	dns_cb_arg.done = false;
+
+	ret = dns_gethostbyname(name, &ipaddr, dns_cb, &dns_cb_arg);
+
+	if (ret == ERR_OK) {
+		dns_cb(name, &ipaddr, &dns_cb_arg);
+	} else if (ret == ERR_INPROGRESS) {
+		start = get_timer(0);
+		sys_timeout(DNS_RESEND_MS, do_dns_tmr, NULL);
+		do {
+			net_lwip_rx(udev, netif);
+			if (dns_cb_arg.done)
+				break;
+			if (ctrlc()) {
+				printf("\nAbort\n");
+				break;
+			}
+		} while (get_timer(start) < DNS_TIMEOUT_MS);
+		sys_untimeout(do_dns_tmr, NULL);
+	}
+
+	net_lwip_remove_netif(netif);
+
+	if (dns_cb_arg.done && dns_cb_arg.host_ipaddr.addr != 0) {
+		if (!var)
+			printf("%s\n", ipaddr_ntoa(&ipaddr));
+		return CMD_RET_SUCCESS;
+	}
+
+	return CMD_RET_FAILURE;
+}
+
+int do_dns(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
+{
+	char *name;
+	char *var = NULL;
+
+	if (argc == 1 || argc > 3)
+		return CMD_RET_USAGE;
+
+	name = argv[1];
+
+	if (argc == 3)
+		var = argv[2];
+
+	if (net_lwip_eth_start() < 0)
+		return CMD_RET_FAILURE;
+
+	return dns_loop(eth_get_dev(), name, var);
+}