zte's code,first commit

Change-Id: I9a04da59e459a9bc0d67f101f700d9d7dc8d681b
diff --git a/ap/app/busybox/src/networking/udhcp/files.c b/ap/app/busybox/src/networking/udhcp/files.c
new file mode 100644
index 0000000..6840f3c
--- /dev/null
+++ b/ap/app/busybox/src/networking/udhcp/files.c
@@ -0,0 +1,216 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * DHCP server config and lease file manipulation
+ *
+ * Rewrite by Russ Dill <Russ.Dill@asu.edu> July 2001
+ *
+ * Licensed under GPLv2, see file LICENSE in this source tree.
+ */
+#include <netinet/ether.h>
+
+#include "common.h"
+#include "dhcpd.h"
+
+/* on these functions, make sure your datatype matches */
+static int FAST_FUNC read_str(const char *line, void *arg)
+{
+	char **dest = arg;
+
+	free(*dest);
+	*dest = xstrdup(line);
+	return 1;
+}
+
+static int FAST_FUNC read_u32(const char *line, void *arg)
+{
+	*(uint32_t*)arg = bb_strtou32(line, NULL, 10);
+	return errno == 0;
+}
+
+static int FAST_FUNC read_staticlease(const char *const_line, void *arg)
+{
+	char *line;
+	char *mac_string;
+	char *ip_string;
+	struct ether_addr mac_bytes; /* it's "struct { uint8_t mac[6]; }" */
+	uint32_t nip;
+
+	/* Read mac */
+	line = (char *) const_line;
+	mac_string = strtok_r(line, " \t", &line);
+	if (!mac_string || !ether_aton_r(mac_string, &mac_bytes))
+		return 0;
+
+	/* Read ip */
+	ip_string = strtok_r(NULL, " \t", &line);
+	if (!ip_string || !udhcp_str2nip(ip_string, &nip))
+		return 0;
+
+	add_static_lease(arg, (uint8_t*) &mac_bytes, nip);
+
+	log_static_leases(arg);
+
+	return 1;
+}
+
+
+struct config_keyword {
+	const char *keyword;
+	int (*handler)(const char *line, void *var) FAST_FUNC;
+	void *var;
+	const char *def;
+};
+
+static const struct config_keyword keywords[] = {
+	/* keyword        handler           variable address               default */
+	{"start"        , udhcp_str2nip   , &server_config.start_ip     , "192.168.0.20"},
+	{"end"          , udhcp_str2nip   , &server_config.end_ip       , "192.168.0.254"},
+	{"interface"    , read_str        , &server_config.interface    , "eth0"},
+	/* Avoid "max_leases value not sane" warning by setting default
+	 * to default_end_ip - default_start_ip + 1: */
+	{"max_leases"   , read_u32        , &server_config.max_leases   , "235"},
+	{"auto_time"    , read_u32        , &server_config.auto_time    , "7200"},
+	{"decline_time" , read_u32        , &server_config.decline_time , "3600"},
+	{"conflict_time", read_u32        , &server_config.conflict_time, "3600"},
+	{"offer_time"   , read_u32        , &server_config.offer_time   , "60"},
+	{"min_lease"    , read_u32        , &server_config.min_lease_sec, "60"},
+	{"lease_file"   , read_str        , &server_config.lease_file   , LEASES_FILE},
+	{"pidfile"      , read_str        , &server_config.pidfile      , "/var/run/udhcpd.pid"},
+	{"siaddr"       , udhcp_str2nip   , &server_config.siaddr_nip   , "0.0.0.0"},
+	/* keywords with no defaults must be last! */
+	{"option"       , udhcp_str2optset, &server_config.options      , ""},
+	{"opt"          , udhcp_str2optset, &server_config.options      , ""},
+	{"notify_file"  , read_str        , &server_config.notify_file  , NULL},
+	{"sname"        , read_str        , &server_config.sname        , NULL},
+	{"boot_file"    , read_str        , &server_config.boot_file    , NULL},
+	{"static_lease" , read_staticlease, &server_config.static_leases, ""},
+};
+enum { KWS_WITH_DEFAULTS = ARRAY_SIZE(keywords) - 6 };
+
+void FAST_FUNC read_config(const char *file)
+{
+	parser_t *parser;
+	const struct config_keyword *k;
+	unsigned i;
+	char *token[2];
+
+	for (i = 0; i < KWS_WITH_DEFAULTS; i++)
+		keywords[i].handler(keywords[i].def, keywords[i].var);
+
+	parser = config_open(file);
+	while (config_read(parser, token, 2, 2, "# \t", PARSE_NORMAL)) {
+		for (k = keywords, i = 0; i < ARRAY_SIZE(keywords); k++, i++) {
+			if (strcasecmp(token[0], k->keyword) == 0) {
+				if (!k->handler(token[1], k->var)) {
+					bb_error_msg("can't parse line %u in %s",
+							parser->lineno, file);
+					/* reset back to the default value */
+					k->handler(k->def, k->var);
+				}
+				break;
+			}
+		}
+	}
+	config_close(parser);
+
+	server_config.start_ip = ntohl(server_config.start_ip);
+	server_config.end_ip = ntohl(server_config.end_ip);
+}
+
+void FAST_FUNC write_leases(void)
+{
+	int fd;
+	unsigned i;
+	leasetime_t curr;
+	int64_t written_at;
+
+	fd = open_or_warn(server_config.lease_file, O_WRONLY|O_CREAT|O_TRUNC);
+	if (fd < 0)
+		return;
+
+	curr = written_at = time(NULL);
+
+	written_at = SWAP_BE64(written_at);
+	full_write(fd, &written_at, sizeof(written_at));
+
+	for (i = 0; i < server_config.max_leases; i++) {
+		leasetime_t tmp_time;
+
+		if (g_leases[i].lease_nip == 0)
+			continue;
+
+		/* Screw with the time in the struct, for easier writing */
+		tmp_time = g_leases[i].expires;
+
+		g_leases[i].expires -= curr;
+		if ((signed_leasetime_t) g_leases[i].expires < 0)
+			g_leases[i].expires = 0;
+		g_leases[i].expires = htonl(g_leases[i].expires);
+
+		/* No error check. If the file gets truncated,
+		 * we lose some leases on restart. Oh well. */
+		full_write(fd, &g_leases[i], sizeof(g_leases[i]));
+
+		/* Then restore it when done */
+		g_leases[i].expires = tmp_time;
+	}
+	close(fd);
+
+	if (server_config.notify_file) {
+		char *argv[3];
+		argv[0] = server_config.notify_file;
+		argv[1] = server_config.lease_file;
+		argv[2] = NULL;
+		spawn_and_wait(argv);
+	}
+}
+
+void FAST_FUNC read_leases(const char *file)
+{
+	struct dyn_lease lease;
+	int64_t written_at, time_passed;
+	int fd;
+#if defined CONFIG_UDHCP_DEBUG && CONFIG_UDHCP_DEBUG >= 1
+	unsigned i = 0;
+#endif
+
+	fd = open_or_warn(file, O_RDONLY);
+	if (fd < 0)
+		return;
+
+	if (full_read(fd, &written_at, sizeof(written_at)) != sizeof(written_at))
+		goto ret;
+	written_at = SWAP_BE64(written_at);
+
+	time_passed = time(NULL) - written_at;
+	/* Strange written_at, or lease file from old version of udhcpd
+	 * which had no "written_at" field? */
+	if ((uint64_t)time_passed > 12 * 60 * 60)
+		goto ret;
+
+	while (full_read(fd, &lease, sizeof(lease)) == sizeof(lease)) {
+//FIXME: what if it matches some static lease?
+		uint32_t y = ntohl(lease.lease_nip);
+		if (y >= server_config.start_ip && y <= server_config.end_ip) {
+			signed_leasetime_t expires = ntohl(lease.expires) - (signed_leasetime_t)time_passed;
+			if (expires <= 0)
+				continue;
+			/* NB: add_lease takes "relative time", IOW,
+			 * lease duration, not lease deadline. */
+			if (add_lease(lease.lease_mac, lease.lease_nip,
+					expires,
+					lease.hostname, sizeof(lease.hostname)
+				) == 0
+			) {
+				bb_error_msg("too many leases while loading %s", file);
+				break;
+			}
+#if defined CONFIG_UDHCP_DEBUG && CONFIG_UDHCP_DEBUG >= 1
+			i++;
+#endif
+		}
+	}
+	log1("Read %d leases", i);
+ ret:
+	close(fd);
+}