net: lwip: nfs: Port the NFS code to work with lwIP

After the preparatory patches moved most of the NFS code into common
files we now add the code to enable NFS support with lwIP.

Signed-off-by: Andrew Goodbody <andrew.goodbody@linaro.org>
Acked-by: Jerome Forissier <jerome.forissier@linaro.org>

cmd/Kconfig

@@ -2116,20 +2116,6 @@ config CMD_RARP
 	help
 	  Boot image via network using RARP/TFTP protocol
 
-config CMD_NFS
-	bool "nfs"
-	help
-	  Boot image via network using NFS protocol.
-
-config NFS_TIMEOUT
-	int "Timeout in milliseconds for NFS mounts"
-	depends on CMD_NFS
-	default 2000
-	help
-	  Timeout in milliseconds used in NFS protocol.  If you encounter
-	  "ERROR: Cannot umount" in nfs command, try longer timeout such as
-	  10000.
-
 config SYS_DISABLE_AUTOLOAD
 	bool "Disable automatically loading files over the network"
 	depends on CMD_BOOTP || CMD_DHCP || CMD_NFS || CMD_RARP
@@ -2224,6 +2210,20 @@ config CMD_MDIO
 	  The MDIO interface is orthogonal to the MII interface and extends
 	  it by adding access to more registers through indirect addressing.
 
+config CMD_NFS
+	bool "nfs"
+	help
+	  Boot image via network using NFS protocol.
+
+config NFS_TIMEOUT
+	int "Timeout in milliseconds for NFS mounts"
+	depends on CMD_NFS
+	default 2000
+	help
+	  Timeout in milliseconds used in NFS protocol.  If you encounter
+	  "ERROR: Cannot umount" in nfs command, try longer timeout such as
+	  10000.
+
 config CMD_PING
 	bool "ping"
 	select PROT_RAW_LWIP if NET_LWIP

cmd/lwip/Makefile

@@ -1,5 +1,6 @@
 obj-$(CONFIG_CMD_DHCP) += dhcp.o
 obj-$(CONFIG_CMD_DNS) += dns.o
+obj-$(CONFIG_CMD_NFS) += nfs.o
 obj-$(CONFIG_CMD_PING) += ping.o
 obj-$(CONFIG_CMD_SNTP) += sntp.o
 obj-$(CONFIG_CMD_TFTPBOOT) += tftp.o

cmd/lwip/nfs.c

@@ -0,0 +1,11 @@
+// SPDX-License-Identifier: GPL-2.0+
+/* Copyright (C) 2025 Linaro Ltd. */
+
+#include <command.h>
+#include <net.h>
+
+U_BOOT_CMD(nfs,	3,	1,	do_nfs,
+	   "boot image via network using NFS protocol",
+	   "[loadAddress] [[hostIPaddr:]bootfilename]"
+	  );
+

include/net-lwip.h

@@ -51,6 +51,7 @@ int net_lwip_dns_resolve(char *name_or_ip, ip_addr_t *ip);
 bool wget_validate_uri(char *uri);
 
 int do_dns(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[]);
+int do_nfs(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[]);
 int do_wget(struct cmd_tbl *cmdtp, int flag, int argc, char * const argv[]);
 
 #endif /* __NET_LWIP_H__ */

net/lwip/Makefile

@@ -4,6 +4,7 @@ obj-$(CONFIG_$(PHASE_)DM_ETH) += net-lwip.o
 obj-$(CONFIG_CMD_DHCP) += dhcp.o
 obj-$(CONFIG_DNS) += dns.o
 obj-$(CONFIG_LWIP_ICMP_SHOW_UNREACH) += icmp_unreach.o
+obj-$(CONFIG_CMD_NFS) += nfs.o
 obj-$(CONFIG_CMD_TFTPBOOT) += tftp.o
 obj-$(CONFIG_WGET) += wget.o
 

net/lwip/nfs.c

@@ -0,0 +1,286 @@
+// SPDX-License-Identifier: GPL-2.0+
+/* Copyright (C) 2025 Linaro Ltd. */
+
+#include <console.h>
+#include <display_options.h>
+#include <env.h>
+#include <image.h>
+#include <linux/kconfig.h>
+#include <lwip/timeouts.h>
+#include <lwip/udp.h>
+#include <net.h>
+#include "../nfs-common.h"
+#include <time.h>
+
+static ulong timer_start;
+
+static struct nfs_ctx {
+	ip_addr_t nfs_server;
+	struct udp_pcb *pcb;
+} sess_ctx;
+
+/**************************************************************************
+ * RPC_LOOKUP - Lookup RPC Port numbers
+ **************************************************************************
+ */
+void rpc_req(int rpc_prog, int rpc_proc, uint32_t *data, int datalen)
+{
+	struct pbuf *pb;
+	int pktlen;
+	int sport;
+	err_t err;
+
+	pb = pbuf_alloc(PBUF_TRANSPORT, sizeof(struct rpc_t), PBUF_RAM);
+	if (!pb) {
+		debug("Failed to allocate pbuf to build RPC packet\n");
+		return;
+	}
+
+	rpc_req_common(rpc_prog, rpc_proc, data, datalen,
+		       pb->payload, &pktlen, &sport);
+
+	pbuf_realloc(pb, (u16_t)pktlen);
+
+	err = udp_sendto(sess_ctx.pcb, pb, &sess_ctx.nfs_server, sport);
+	debug_cond((err != ERR_OK), "Failed to send UDP packet err = %d\n", err);
+	pbuf_free(pb);
+}
+
+void nfs_refresh_timeout(void)
+{
+	timer_start = get_timer(0);
+}
+
+static void nfs_recv(void *arg, struct udp_pcb *pcb, struct pbuf *p,
+		     const ip_addr_t *addr, u16_t port)
+{
+	struct nfs_ctx *ctx = arg;
+	int plen;
+	struct rpc_t rpc_pkt;
+
+	if (addr->addr != ctx->nfs_server.addr)
+		goto exitfree;
+
+	if (p->tot_len > sizeof(struct rpc_t))
+		goto exitfree;
+
+	plen = pbuf_copy_partial(p, &rpc_pkt.u.data[0], sizeof(rpc_pkt), 0);
+	nfs_pkt_recv(&rpc_pkt.u.data[0], plen);
+
+exitfree:
+	pbuf_free(p);
+}
+
+static int nfs_udp_init(struct nfs_ctx *ctx)
+{
+	ctx->pcb = udp_new();
+	if (!ctx->pcb)
+		return -ENOMEM;
+
+	ctx->pcb->local_port = nfs_our_port;
+	udp_recv(ctx->pcb, nfs_recv, ctx);
+
+	return 0;
+}
+
+static int nfs_timeout_check(void)
+{
+	if (get_timer(timer_start) < nfs_timeout)
+		return 0;
+	if (++nfs_timeout_count < NFS_RETRY_COUNT) {
+		puts("T ");
+		timer_start = get_timer(0);
+		nfs_send();
+		return 0;
+	}
+
+	return 1;
+}
+
+static int nfs_loop(struct udevice *udev, ulong addr, char *fname,
+		    ip_addr_t srvip)
+{
+	struct netif *netif;
+	int ret;
+
+	nfs_download_state = NETLOOP_FAIL;
+	net_set_state(NETLOOP_FAIL);
+
+	if (!fname || addr == 0)
+		return -1;
+
+	netif = net_lwip_new_netif(udev);
+	if (!netif)
+		return -1;
+
+	nfs_filename = nfs_basename(fname);
+	nfs_path     = nfs_dirname(fname);
+
+	printf("Using %s device\n", eth_get_name());
+
+	printf("File transfer via NFS from server %s; our IP address is %s\n",
+	       ip4addr_ntoa(&srvip), env_get("ipaddr"));
+
+	printf("\nFilename '%s/%s'.", nfs_path, nfs_filename);
+
+	if (net_boot_file_expected_size_in_blocks) {
+		printf(" Size is 0x%x Bytes = ",
+		       net_boot_file_expected_size_in_blocks << 9);
+		print_size(net_boot_file_expected_size_in_blocks << 9, "");
+	}
+	printf("\nLoad address: 0x%lx\nLoading: *\b", addr);
+	image_load_addr = addr;
+
+	nfs_timeout_count = 0;
+	nfs_state = STATE_PRCLOOKUP_PROG_MOUNT_REQ;
+
+	ret = nfs_udp_init(&sess_ctx);
+	if (ret < 0) {
+		net_lwip_remove_netif(netif);
+		debug("Failed to init network interface, aborting for error = %d\n", ret);
+		return ret;
+	}
+
+	net_set_state(NETLOOP_CONTINUE);
+
+	sess_ctx.nfs_server.addr = srvip.addr;
+
+	nfs_send();
+
+	timer_start = get_timer(0);
+	do {
+		net_lwip_rx(udev, netif);
+		if (net_state != NETLOOP_CONTINUE)
+			break;
+		if (ctrlc()) {
+			printf("\nAbort\n");
+			break;
+		}
+
+		if (nfs_timeout_check())
+			break;
+	} while (true);
+	debug("%s: Loop exit at %lu\n", __func__, get_timer(0));
+
+	net_lwip_remove_netif(netif);
+
+	if (net_state == NETLOOP_SUCCESS) {
+		ret = 0;
+		if (net_boot_file_size > 0) {
+			printf("Bytes transferred = %u (%x hex)\n",
+			       net_boot_file_size, net_boot_file_size);
+			env_set_hex("filesize", net_boot_file_size);
+			env_set_hex("fileaddr", image_load_addr);
+		}
+
+	} else {
+		debug("%s: NFS loop failed\n", __func__);
+		ret = -1;
+	}
+
+	return ret;
+}
+
+int do_nfs(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
+{
+	int ret = CMD_RET_SUCCESS;
+	char *arg = NULL;
+	char *words[2] = { };
+	char *fname = NULL;
+	char *server_ip = NULL;
+	char *end;
+	ip_addr_t srvip;
+	ulong laddr;
+	ulong addr;
+	int i;
+
+	laddr = env_get_ulong("loadaddr", 16, image_load_addr);
+
+	switch (argc) {
+	case 1:
+		fname = env_get("bootfile");
+		break;
+	case 2:
+		/*
+		 * Only one arg - accept two forms:
+		 * Just load address, or just boot file name. The latter
+		 * form must be written in a format which can not be
+		 * mis-interpreted as a valid number.
+		 */
+		addr = hextoul(argv[1], &end);
+		if (end == (argv[1] + strlen(argv[1]))) {
+			laddr = addr;
+			fname = env_get("bootfile");
+		} else {
+			arg = strdup(argv[1]);
+		}
+		break;
+	case 3:
+		laddr = hextoul(argv[1], NULL);
+		arg = strdup(argv[2]);
+		break;
+	default:
+		ret = CMD_RET_USAGE;
+		goto out;
+	}
+
+	if (!arg)
+		arg = net_boot_file_name;
+
+	if (*arg) {
+		/* Parse [ip:]fname */
+		i = 0;
+		while ((*(words + i) = strsep(&arg, ":")))
+			i++;
+
+		switch (i) {
+		case 2:
+			server_ip = words[0];
+			fname = words[1];
+			break;
+		case 1:
+			fname = words[0];
+			break;
+		default:
+			break;
+		}
+	}
+
+	if (!server_ip)
+		server_ip = env_get("serverip");
+	if (!server_ip) {
+		log_err("*** ERROR: 'serverip' not set\n");
+		ret = CMD_RET_FAILURE;
+		goto out;
+	}
+
+	if (!ipaddr_aton(server_ip, &srvip)) {
+		log_err("error: ipaddr_aton\n");
+		ret = CMD_RET_FAILURE;
+		goto out;
+	}
+
+	if (!fname) {
+		log_err("error: no file name\n");
+		ret = CMD_RET_FAILURE;
+		goto out;
+	}
+
+	if (!laddr) {
+		log_err("error: no load address\n");
+		ret = CMD_RET_FAILURE;
+		goto out;
+	}
+
+	if (net_lwip_eth_start() < 0) {
+		ret = CMD_RET_FAILURE;
+		goto out;
+	}
+
+	if (nfs_loop(eth_get_dev(), laddr, fname, srvip) < 0)
+		ret = CMD_RET_FAILURE;
+out:
+	if (arg != net_boot_file_name)
+		free(arg);
+	return ret;
+}

net/nfs-common.c

@@ -286,9 +286,11 @@ static void nfs_umountall_req(void)
 	u32 *p;
 	int len;
 
-	if ((nfs_server_mount_port == -1) || !fs_mounted)
+	if ((nfs_server_mount_port == -1) || !fs_mounted) {
 		/* Nothing mounted, nothing to umount */
+		net_set_state(NETLOOP_FAIL);
 		return;
+	}
 
 	p = &data[0];
 	p = rpc_add_credentials(p);