net: lwip: add dns command

Add CMD_DNS when NET_LWIP is enabled to provide the dns command using
lwIP.

Signed-off-by: Jerome Forissier <jerome.forissier@linaro.org>
Acked-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>

diff --git a/cmd/Kconfig b/cmd/Kconfig
index b7d1dd028a1265a252db4a24d6d6dbca80b0380b..2791ad5393c1b4fbaa4c452c336bb2ca5637e0a5 100644 (file)
--- a/cmd/Kconfig
+++ b/cmd/Kconfig
@@ -2027,11 +2027,6 @@ config CMD_SNTP
        help
          Synchronize RTC via network
 
-config CMD_DNS
-       bool "dns"
-       help
-         Lookup the IP of a hostname
-
 config CMD_LINK_LOCAL
        bool "linklocal"
        select LIB_RAND
@@ -2079,6 +2074,12 @@ config CMD_DHCP
        help
          Boot image via network using DHCP/TFTP protocol
 
+config CMD_DNS
+       bool "dns"
+       select PROT_DNS_LWIP if NET_LWIP
+       help
+         Lookup the IP of a hostname
+
 config CMD_MII
        bool "mii"
        imply CMD_MDIO

diff --git a/cmd/net-lwip.c b/cmd/net-lwip.c
index feed719beefe922a89af1b427eceba81ac84d7e4..c021da6a6748d431d460402f5f03ba8176978bf5 100644 (file)
--- a/cmd/net-lwip.c
+++ b/cmd/net-lwip.c
@@ -27,3 +27,11 @@ U_BOOT_CMD(
        "[loadAddress] [[hostIPaddr:]bootfilename]"
 );
 #endif
+
+#if defined(CONFIG_CMD_DNS)
+U_BOOT_CMD(
+       dns,    3,      1,      do_dns,
+       "lookup the IP of a hostname",
+       "hostname [envvar]"
+);
+#endif

diff --git a/include/net-lwip.h b/include/net-lwip.h
index 9aa371e962c2e594e2f641289cf1b8d3e65af986..ff9d03b23e80c7990414bbc9b8c3657838770f3c 100644 (file)
--- a/include/net-lwip.h
+++ b/include/net-lwip.h
@@ -17,6 +17,7 @@ struct netif *net_lwip_get_netif(void);
 int net_lwip_rx(struct udevice *udev, struct netif *netif);
 
 int do_dhcp(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[]);
+int do_dns(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[]);
 int do_ping(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[]);
 
 #endif /* __NET_LWIP_H__ */

diff --git a/net/lwip/Makefile b/net/lwip/Makefile
index b5af37a9b182c087235aace66b2db4f0c620cf2c..645d8a8c45749f345c201ba34b1a84f70ac775ea 100644 (file)
--- a/net/lwip/Makefile
+++ b/net/lwip/Makefile
@@ -2,5 +2,6 @@ ccflags-y += -I$(srctree)/lib/lwip/lwip/src/include -I$(srctree)/lib/lwip/u-boot
 
 obj-$(CONFIG_$(SPL_)DM_ETH) += net-lwip.o
 obj-$(CONFIG_CMD_DHCP) += dhcp.o
+obj-$(CONFIG_CMD_DNS) += dns.o
 obj-$(CONFIG_CMD_PING) += ping.o
 obj-$(CONFIG_CMD_TFTPBOOT) += tftp.o

diff --git a/net/lwip/dns.c b/net/lwip/dns.c
new file mode 100644 (file)
index 0000000..4b937fe
--- /dev/null
+++ b/net/lwip/dns.c
@@ -0,0 +1,127 @@
+// SPDX-License-Identifier: GPL-2.0+
+/* Copyright (C) 2024 Linaro Ltd. */
+
+#include <command.h>
+#include <console.h>
+#include <lwip/dns.h>
+#include <lwip/timeouts.h>
+#include <net.h>
+#include <time.h>
+
+#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;
+       }
+
+       if (dns_cb_arg->var)
+               env_set(dns_cb_arg->var, ipstr);
+
+       printf("%s\n", ipstr);
+}
+
+static int dns_loop(struct udevice *udev, const char *name, const char *var)
+{
+       struct dns_cb_arg dns_cb_arg = { };
+       bool has_server = false;
+       struct netif *netif;
+       ip_addr_t ipaddr;
+       ip_addr_t ns;
+       ulong start;
+       char *nsenv;
+       int ret;
+
+       dns_cb_arg.var = var;
+
+       netif = net_lwip_new_netif(udev);
+       if (!netif)
+               return -1;
+
+       dns_init();
+
+       nsenv = env_get("dnsip");
+       if (nsenv && ipaddr_aton(nsenv, &ns)) {
+               dns_setserver(0, &ns);
+               has_server = true;
+       }
+
+       nsenv = env_get("dnsip2");
+       if (nsenv && ipaddr_aton(nsenv, &ns)) {
+               dns_setserver(1, &ns);
+               has_server = true;
+       }
+
+       if (!has_server) {
+               log_err("No valid name server (dnsip/dnsip2)\n");
+               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;
+                       sys_check_timeouts();
+                       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)
+               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];
+
+       eth_set_current();
+
+       return dns_loop(eth_get_dev(), name, var);
+}