dhcp: add client implementation

.github/workflows/check.yml

@@ -71,6 +71,7 @@ jobs:
             libibverbs-dev libasan8 libcmocka-dev libedit-dev libarchive-dev \
             libevent-dev libsmartcols-dev libmnl-dev libnuma-dev python3-pyelftools \
             socat tcpdump traceroute graphviz iproute2 iputils-ping ndisc6 jq \
+            dnsmasq \
             "linux-modules-extra-$(uname -r)"
           if echo $MESON_EXTRA_OPTS | grep -q frr=enabled ; then
             sudo apt-get install -qy --no-install-recommends \

modules/dhcp/api/gr_dhcp.h

@@ -0,0 +1,59 @@
+// SPDX-License-Identifier: BSD-3-Clause
+// Copyright (c) 2025 Anthony Harivel
+
+#pragma once
+
+#include <gr_api.h>
+#include <gr_infra.h>
+#include <gr_net_types.h>
+
+#include <stdint.h>
+
+typedef enum dhcp_state : uint8_t {
+	DHCP_STATE_INIT = 0,
+	DHCP_STATE_SELECTING,
+	DHCP_STATE_REQUESTING,
+	DHCP_STATE_BOUND,
+	DHCP_STATE_RENEWING,
+	DHCP_STATE_REBINDING,
+} dhcp_state_t;
+
+struct gr_dhcp_status {
+	uint16_t iface_id;
+	dhcp_state_t state;
+	ip4_addr_t server_ip;
+	ip4_addr_t assigned_ip;
+	uint32_t lease_time;
+	uint32_t renewal_time; // T1
+	uint32_t rebind_time; // T2
+};
+
+#define GR_DHCP_MODULE 0xd4c9
+
+// list ////////////////////////////////////////////////////////////////////////
+
+#define GR_DHCP_LIST REQUEST_TYPE(GR_DHCP_MODULE, 0x01)
+
+// struct gr_dhcp_list_req { };
+
+// STREAM(struct gr_dhcp_status);
+
+// start ///////////////////////////////////////////////////////////////////////
+
+#define GR_DHCP_START REQUEST_TYPE(GR_DHCP_MODULE, 0x02)
+
+struct gr_dhcp_start_req {
+	uint16_t iface_id;
+};
+
+// struct gr_dhcp_start_resp { };
+
+// stop ////////////////////////////////////////////////////////////////////////
+
+#define GR_DHCP_STOP REQUEST_TYPE(GR_DHCP_MODULE, 0x03)
+
+struct gr_dhcp_stop_req {
+	uint16_t iface_id;
+};
+
+// struct gr_dhcp_stop_resp { };

modules/dhcp/api/meson.build

@@ -0,0 +1,5 @@
+# SPDX-License-Identifier: BSD-3-Clause
+# Copyright (c) 2025 Anthony Harivel
+
+api_headers += files('gr_dhcp.h')
+api_inc += include_directories('.')

modules/dhcp/cli/dhcp.c

@@ -0,0 +1,177 @@
+// SPDX-License-Identifier: BSD-3-Clause
+// Copyright (c) 2025 Anthony Harivel
+
+#include <gr_cli.h>
+#include <gr_cli_iface.h>
+#include <gr_dhcp.h>
+#include <gr_net_types.h>
+#include <gr_table.h>
+
+#include <ecoli.h>
+#include <libsmartcols.h>
+
+#include <errno.h>
+#include <stdio.h>
+#include <string.h>
+
+static cmd_status_t dhcp_enable_cmd(struct gr_api_client *c, const struct ec_pnode *p) {
+	const char *iface_name = arg_str(p, "IFACE");
+	struct gr_dhcp_start_req req;
+	struct gr_iface *iface;
+
+	iface = iface_from_name(c, iface_name);
+	if (iface == NULL)
+		return CMD_ERROR;
+
+	req.iface_id = iface->id;
+	free(iface);
+
+	if (gr_api_client_send_recv(c, GR_DHCP_START, sizeof(req), &req, NULL) < 0)
+		return CMD_ERROR;
+
+	return CMD_SUCCESS;
+}
+
+static cmd_status_t dhcp_disable_cmd(struct gr_api_client *c, const struct ec_pnode *p) {
+	const char *iface_name = arg_str(p, "IFACE");
+	struct gr_dhcp_stop_req req;
+	struct gr_iface *iface;
+
+	iface = iface_from_name(c, iface_name);
+	if (iface == NULL)
+		return CMD_ERROR;
+
+	req.iface_id = iface->id;
+	free(iface);
+
+	if (gr_api_client_send_recv(c, GR_DHCP_STOP, sizeof(req), &req, NULL) < 0)
+		return CMD_ERROR;
+
+	return CMD_SUCCESS;
+}
+
+static const char *dhcp_state_str(enum dhcp_state state) {
+	switch (state) {
+	case DHCP_STATE_INIT:
+		return "INIT";
+	case DHCP_STATE_SELECTING:
+		return "SELECTING";
+	case DHCP_STATE_REQUESTING:
+		return "REQUESTING";
+	case DHCP_STATE_BOUND:
+		return "BOUND";
+	case DHCP_STATE_RENEWING:
+		return "RENEWING";
+	case DHCP_STATE_REBINDING:
+		return "REBINDING";
+	default:
+		return "UNKNOWN";
+	}
+}
+
+static cmd_status_t dhcp_show_cmd(struct gr_api_client *c, const struct ec_pnode *) {
+	const struct gr_dhcp_status *status;
+	struct libscols_table *table;
+	int ret;
+
+	table = scols_new_table();
+	if (table == NULL)
+		return CMD_ERROR;
+
+	scols_table_new_column(table, "INTERFACE", 0, 0);
+	scols_table_new_column(table, "STATE", 0, 0);
+	scols_table_new_column(table, "ADDRESS", 0, 0);
+	scols_table_new_column(table, "SERVER", 0, 0);
+	scols_table_new_column(table, "LEASE", 0, SCOLS_FL_RIGHT);
+
+	gr_api_client_stream_foreach (status, ret, c, GR_DHCP_LIST, 0, NULL) {
+		struct libscols_line *line = scols_table_new_line(table, NULL);
+		struct gr_iface *iface = iface_from_id(c, status->iface_id);
+
+		if (iface != NULL) {
+			scols_line_sprintf(line, 0, "%s", iface->name);
+			free(iface);
+		} else {
+			scols_line_sprintf(line, 0, "%u", status->iface_id);
+		}
+
+		scols_line_sprintf(line, 1, "%s", dhcp_state_str(status->state));
+
+		if (status->assigned_ip != 0) {
+			scols_line_sprintf(line, 2, IP4_F, &status->assigned_ip);
+		} else {
+			scols_line_sprintf(line, 2, "-");
+		}
+
+		if (status->server_ip != 0) {
+			scols_line_sprintf(line, 3, IP4_F, &status->server_ip);
+		} else {
+			scols_line_sprintf(line, 3, "-");
+		}
+
+		if (status->lease_time != 0)
+			scols_line_sprintf(line, 4, "%us", status->lease_time);
+		else
+			scols_line_sprintf(line, 4, "-");
+	}
+
+	if (ret < 0) {
+		scols_unref_table(table);
+		return CMD_ERROR;
+	}
+
+	scols_print_table(table);
+	scols_unref_table(table);
+
+	return CMD_SUCCESS;
+}
+
+static int ctx_init(struct ec_node *root) {
+	int ret;
+
+	ret = CLI_COMMAND(
+		CLI_CONTEXT(root, CTX_ARG("dhcp", "DHCP client.")),
+		"enable IFACE",
+		dhcp_enable_cmd,
+		"Enable DHCP on interface.",
+		with_help(
+			"Interface name.",
+			ec_node_dyn("IFACE", complete_iface_names, INT2PTR(GR_IFACE_TYPE_UNDEF))
+		)
+	);
+	if (ret < 0)
+		return ret;
+
+	ret = CLI_COMMAND(
+		CLI_CONTEXT(root, CTX_ARG("dhcp", "DHCP client.")),
+		"disable IFACE",
+		dhcp_disable_cmd,
+		"Disable DHCP on interface.",
+		with_help(
+			"Interface name.",
+			ec_node_dyn("IFACE", complete_iface_names, INT2PTR(GR_IFACE_TYPE_UNDEF))
+		)
+	);
+	if (ret < 0)
+		return ret;
+
+	ret = CLI_COMMAND(
+		CLI_CONTEXT(root, CTX_ARG("dhcp", "DHCP client.")),
+		"show",
+		dhcp_show_cmd,
+		"Show DHCP client status."
+	);
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+
+static struct cli_context ctx = {
+	.name = "dhcp",
+	.init = ctx_init,
+};
+
+static void __attribute__((constructor, used)) init(void) {
+	cli_context_register(&ctx);
+}

modules/dhcp/cli/meson.build

@@ -0,0 +1,6 @@
+# SPDX-License-Identifier: BSD-3-Clause
+# Copyright (c) 2025 Anthony Harivel
+
+cli_src += files(
+  'dhcp.c',
+)