sys: net: add UHCP protocol code and gnrc client implementation

Makefile.dep

@@ -25,6 +25,12 @@ ifneq (,$(filter netdev2_ieee802154,$(USEMODULE)))
   USEMODULE += ieee802154
 endif
 
+ifneq (,$(filter gnrc_uhcpc,$(USEMODULE)))
+    USEMODULE += uhcpc
+    USEMODULE += gnrc_conn_udp
+    USEMODULE += fmt
+endif
+
 ifneq (,$(filter gnrc_%,$(filter-out gnrc_netapi gnrc_netreg gnrc_netif% gnrc_pktbuf,$(USEMODULE))))
   USEMODULE += gnrc
 endif

sys/Makefile

@@ -78,6 +78,14 @@ ifneq (,$(filter hamming256,$(USEMODULE)))
     DIRS += ecc/hamming256
 endif
 
+ifneq (,$(filter uhcpc,$(USEMODULE)))
+    DIRS += net/application_layer/uhcp
+endif
+
+ifneq (,$(filter gnrc_uhcpc,$(USEMODULE)))
+    DIRS += net/gnrc/application_layer/uhcpc
+endif
+
 ifneq (,$(filter netopt,$(USEMODULE)))
     DIRS += net/crosslayer/netopt
 endif

sys/auto_init/auto_init.c

@@ -213,6 +213,11 @@ void auto_init(void)
     gnrc_ipv6_netif_init_by_dev();
 #endif
 
+#ifdef MODULE_GNRC_UHCPC
+    extern void auto_init_gnrc_uhcpc(void);
+    auto_init_gnrc_uhcpc();
+#endif
+
 /* initialize sensors and actuators */
 #ifdef MODULE_AUTO_INIT_SAUL
     DEBUG("auto_init SAUL\n");

sys/include/net/uhcp.h

@@ -0,0 +1,179 @@
+/*
+ * Copyright (C) 2016 Kaspar Schleiser <kaspar@schleiser.de>
+ *
+ * This file is subject to the terms and conditions of the GNU Lesser
+ * General Public License v2.1. See the file LICENSE in the top level
+ * directory for more details.
+ */
+
+/**
+ * @defgroup    net_uhcp UHCP
+ * @ingroup     net
+ * @brief       Provides UHCP (micro host configuration protocol)
+ * @{
+ *
+ * @file
+ * @brief   UHCP header
+ *
+ * @author  Kaspar Schleiser <kaspar@schleiser.de>
+ */
+
+#ifndef UHCP_H
+#define UHCP_H
+
+#include <stdint.h>
+#include <stddef.h>
+#include <arpa/inet.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/** @brief UHCP magic number */
+#define UHCP_MAGIC  (0x55484350) /* "UHCP" in hex */
+
+/** @brief UHCP version of this header */
+#define UHCP_VER    (0)
+
+/** @brief UHCP port number */
+#define UHCP_PORT       (12345U)
+
+/** @brief UHCP port number (as string for e.g., getaddrinfo() service arg */
+#define UHCP_PORT_STR   "12345"
+
+/** @brief Enum containing possible UHCP packet types */
+typedef enum {
+    UHCP_REQ,               /**< packet is a request packet */
+    UHCP_PUSH               /**< packet is a push / answer packet */
+} uhcp_type_t;
+
+/**
+ * @brief UHCP packet header struct
+ */
+typedef struct __attribute__((packed)) {
+    uint32_t uhcp_magic;    /**< always contains UHCP in hex */
+    uint8_t ver_type;       /**< four bits version number, four bits
+                                 packet type (see uchp_type_t) */
+} uhcp_hdr_t;
+
+/**
+ * @brief struct for request packets
+ *
+ * @extends uhcp_hdr_t
+ */
+typedef struct __attribute__((packed)) {
+    uhcp_hdr_t hdr;         /**< member holding parent type */
+    uint8_t prefix_len;     /**< contains the requested prefix length */
+} uhcp_req_t;
+
+/**
+ * @brief struct for push packets
+ *
+ * @extends uhcp_hdr_t
+ */
+typedef struct __attribute__((packed)) {
+    uhcp_hdr_t hdr;         /**< member holding parent type */
+    uint8_t prefix_len;     /**< contains the prefix length of assigned
+                                 prefix */
+    uint8_t prefix[];       /**< contains the assigned prefix */
+} uhcp_push_t;
+
+/** @brief typedef for interface handle */
+typedef unsigned uhcp_iface_t;
+
+/**
+ * @brief handle incoming UDP packet
+ *
+ * This function should be called by UHCP server/client network code for every
+ * incoming UDP packet destined to UCHP_PORT.
+ *
+ * @param[in]   buf     buffer containing UDP packet
+ * @param[in]   len     length of @c buf
+ * @param[in]   src     ptr to IPv6 source address
+ * @param[in]   port    source port of packet
+ * @param[in]   iface   interface number of incoming packet
+ */
+void uhcp_handle_udp(uint8_t *buf, size_t len, uint8_t *src, uint16_t port, uhcp_iface_t iface);
+
+/**
+ * @brief handle incoming UHCP request packet
+ *
+ * This function will be called by uhcp_handle_udp() for incoming request
+ * packet.
+ *
+ * @internal
+ *
+ * @param[in]   req     ptr to UHCP request header
+ * @param[in]   src     ptr to IPv6 source address
+ * @param[in]   port    source port of packet
+ * @param[in]   iface   number of interface the packet came in
+ */
+void uhcp_handle_req(uhcp_req_t *req, uint8_t *src, uint16_t port, uhcp_iface_t iface);
+
+/**
+ * @brief handle incoming UHCP push packet
+ *
+ * This function will be called by uhcp_handle_udp() for incoming push
+ * packet.
+ *
+ * @internal
+ *
+ * @param[in]   req     ptr to UHCP push header
+ * @param[in]   src     ptr to IPv6 source address
+ * @param[in]   port    source port of packet
+ * @param[in]   iface   number of interface the packet came in
+ */
+void uhcp_handle_push(uhcp_push_t *req, uint8_t *src, uint16_t port, uhcp_iface_t iface);
+
+/**
+ * @brief handle incoming prefix (as parsed from push packet)
+ *
+ * Supposed to be implemented by UHCP client implementations.
+ *
+ * The function might be called with an already configured prefix. In that
+ * case, the lifetime *MUST* be updated.
+ *
+ * If the function is called with a different prefix than before, the old
+ * prefix *MUST* be considered obsolete.
+ *
+ * @param[in]   prefix      ptr to assigned prefix
+ * @param[in]   prefix_len  length of assigned prefix
+ * @param[in]   lifetime    lifetime of prefix
+ * @param[in]   src         ptr to IPv6 source address
+ * @param[in]   iface       number of interface the packet came in
+ */
+void uhcp_handle_prefix(uint8_t *prefix, uint8_t prefix_len, uint16_t lifetime, uint8_t *src, uhcp_iface_t iface);
+
+/**
+ * @brief function to set constant values in UHCP header
+ *
+ * @internal
+ *
+ * @param[out]  hdr     hdr to set up
+ * @param[in]   type    type of packet (request or push)
+ */
+static inline void uhcp_hdr_set(uhcp_hdr_t *hdr, uhcp_type_t type)
+{
+    hdr->uhcp_magic = htonl(UHCP_MAGIC);
+    hdr->ver_type = (UHCP_VER << 4) | (type & 0xF);
+}
+
+/**
+ * @brief UDP send function used by UHCP client / server
+ *
+ * Supposed to be implemented by UHCP clients.
+ *
+ * @param[in]   buf         buffer to send
+ * @param[in]   len         length of buf
+ * @param[in]   dst         ptr to IPv6 destination address
+ * @param[in]   dst_port    destination port
+ * @param[in]   dst_iface   interface number of destination interface
+ */
+int udp_sendto(uint8_t *buf, size_t len, uint8_t *dst, uint16_t dst_port, uhcp_iface_t dst_iface);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* UHCP_H */
+/** @} */

sys/net/application_layer/uhcp/Makefile

@@ -0,0 +1,3 @@
+MODULE=uhcpc
+CFLAGS += -DUHCP_CLIENT
+include $(RIOTBASE)/Makefile.base

sys/net/application_layer/uhcp/uhcp.c

@@ -0,0 +1,111 @@
+/*
+ * Copyright (C) 2016 Kaspar Schleiser <kaspar@schleiser.de>
+ *
+ * This file is subject to the terms and conditions of the GNU Lesser
+ * General Public License v2.1. See the file LICENSE in the top level
+ * directory for more details.
+ */
+
+#include <stdio.h>
+
+#include <arpa/inet.h>
+#include <netinet/in.h>
+#include <string.h>
+
+#include "net/uhcp.h"
+
+void uhcp_handle_udp(uint8_t *buf, size_t len, uint8_t *src, uint16_t port, uhcp_iface_t iface)
+{
+    char addr_str[INET6_ADDRSTRLEN];
+    inet_ntop(AF_INET6, src, addr_str, INET6_ADDRSTRLEN);
+    printf("got packet from %s port %u\n", addr_str, (unsigned)port);
+
+    if (len < sizeof(uhcp_req_t)) {
+        puts("error: packet too small.");
+        return;
+    }
+
+    uhcp_hdr_t *hdr = (uhcp_hdr_t *)buf;
+
+    if (! (ntohl(hdr->uhcp_magic) == UHCP_MAGIC)) {
+        puts("error: wrong magic number.");
+        return;
+    }
+
+    unsigned ver, type;
+    ver = hdr->ver_type >> 4;
+    type = hdr->ver_type & 0xF;
+
+    if (ver != UHCP_VER) {
+        puts("error: wrong protocol version.");
+    }
+
+    switch(type) {
+#ifdef UHCP_SERVER
+        case UHCP_REQ:
+            if (len < sizeof(uhcp_req_t)) {
+                puts("error: request too small\n");
+            }
+            else {
+                uhcp_handle_req((uhcp_req_t*)hdr, src, port, iface);
+            }
+            break;
+#endif
+#ifdef UHCP_CLIENT
+        case UHCP_PUSH:
+            {
+                uhcp_push_t *push = (uhcp_push_t*)hdr;
+                if ((len < sizeof(uhcp_push_t))
+                    || (len < (sizeof(uhcp_push_t) + (push->prefix_len >> 3)))
+                   ) {
+                    puts("error: request too small\n");
+                }
+                else {
+                    uhcp_handle_push(push, src, port, iface);
+                }
+                break;
+            }
+#endif
+        default:
+             puts("error: unexpected type\n");
+    }
+}
+
+#ifdef UHCP_SERVER
+extern char _prefix[16];
+extern unsigned _prefix_len;
+void uhcp_handle_req(uhcp_req_t *req, uint8_t *src, uint16_t port, uhcp_iface_t iface)
+{
+    size_t prefix_bytes = (_prefix_len + 7)>>3;
+    uint8_t packet[sizeof(uhcp_push_t) + prefix_bytes];
+
+    uhcp_push_t *reply = (uhcp_push_t *)packet;
+    uhcp_hdr_set(&reply->hdr, UHCP_PUSH);
+
+    reply->prefix_len = _prefix_len;
+    memcpy(reply->prefix, _prefix, prefix_bytes);
+
+    int res = udp_sendto(packet, sizeof(packet), src, port, iface);
+    if (res == -1) {
+        printf("uhcp_handle_req(): udp_sendto() res=%i\n", res);
+    }
+}
+#endif /* UHCP_SERVER */
+
+#ifdef UHCP_CLIENT
+void uhcp_handle_push(uhcp_push_t *req, uint8_t *src, uint16_t port, uhcp_iface_t iface)
+{
+    char addr_str[INET6_ADDRSTRLEN];
+    char prefix_str[INET6_ADDRSTRLEN];
+    inet_ntop(AF_INET6, src, addr_str, INET6_ADDRSTRLEN);
+    uint8_t prefix[16];
+    size_t prefix_bytes = (req->prefix_len + 7)>>3;
+    memset(prefix + 16 - prefix_bytes, '\0', 16 - prefix_bytes);
+    memcpy(prefix, req->prefix, prefix_bytes);
+
+    inet_ntop(AF_INET6, prefix, prefix_str, INET6_ADDRSTRLEN);
+
+    printf("uhcp: push from %s:%u prefix=%s/%u\n", addr_str, (unsigned)port, prefix_str, req->prefix_len);
+    uhcp_handle_prefix(prefix, req->prefix_len, 0xFFFF, src, iface);
+}
+#endif