Fold tables.c into options.c and stop exporting the one

table (dhcp_options) involved. Provide functions
code_to_name(), name_to_code(), code_to_format() and
replace direct access to dhcp_options with them. Eliminate
unneeded 'struct option'.

Unhook tables.c from Makefile.

5 files changed, 387 insertions, 65 deletions

diff --git a/sbin/dhclient/Makefile b/sbin/dhclient/Makefile
index 685425f0473..b0113857654 100644
--- a/sbin/dhclient/Makefile
+++ b/sbin/dhclient/Makefile
@@ -1,4 +1,4 @@
-# $OpenBSD: Makefile,v 1.19 2017/04/09 20:44:13 krw Exp $
+# $OpenBSD: Makefile,v 1.20 2017/07/08 20:38:31 krw Exp $
 #
 # Copyright (c) 1996, 1997 The Internet Software Consortium.
 # All rights reserved.
@@ -33,7 +33,7 @@
 .include <bsd.own.mk>
 
 SRCS=	dhclient.c clparse.c dispatch.c bpf.c options.c \
-	conflex.c log.c packet.c tables.c \
+	conflex.c log.c packet.c  \
 	parse.c privsep.c kroute.c
 
 PROG=	dhclient
diff --git a/sbin/dhclient/clparse.c b/sbin/dhclient/clparse.c
index 1cb8246ebd8..afe5db7b61e 100644
--- a/sbin/dhclient/clparse.c
+++ b/sbin/dhclient/clparse.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: clparse.c,v 1.118 2017/07/08 15:26:27 krw Exp $	*/
+/*	$OpenBSD: clparse.c,v 1.119 2017/07/08 20:38:31 krw Exp $	*/
 
 /* Parser for dhclient config and lease files. */
 
@@ -409,10 +409,8 @@ parse_option_list(FILE *cfile, uint8_t *list, size_t sz)
 		 * lists.  They are not really options and it makes no sense
 		 * to request, require or ignore them.
 		 */
-		for (i = 1; i < DHO_END; i++)
-			if (!strcasecmp(dhcp_options[i].name, val))
-				break;
 
+		i = name_to_code(val);
 		if (i == DHO_END) {
 			parse_warn("expecting option name.");
 			goto syntaxerror;
@@ -637,12 +635,8 @@ parse_option_decl(FILE *cfile, struct option_data *options)
 	}
 
 	/* Look up the actual option info. */
-	fmt = NULL;
-	for (code = 0; code < DHO_COUNT; code++)
-		if (strcasecmp(dhcp_options[code].name, val) == 0)
-			break;
-
-	if (code > 255) {
+	code = name_to_code(val);
+	if (code == DHO_END) {
 		parse_warn("unknown option name.");
 		skip_to_semi(cfile);
 		return (-1);
@@ -650,7 +644,7 @@ parse_option_decl(FILE *cfile, struct option_data *options)
 
 	/* Parse the option data. */
 	do {
-		for (fmt = dhcp_options[code].format; *fmt; fmt++) {
+		for (fmt = code_to_format(code); *fmt; fmt++) {
 			if (*fmt == 'A')
 				break;
 			switch (*fmt) {
diff --git a/sbin/dhclient/dhclient.c b/sbin/dhclient/dhclient.c
index 84e5007ea77..579be485671 100644
--- a/sbin/dhclient/dhclient.c
+++ b/sbin/dhclient/dhclient.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: dhclient.c,v 1.460 2017/07/08 00:36:10 krw Exp $	*/
+/*	$OpenBSD: dhclient.c,v 1.461 2017/07/08 20:38:31 krw Exp $	*/
 
 /*
  * Copyright 2004 Henning Brauer <henning@openbsd.org>
@@ -1187,7 +1187,7 @@ packet_to_lease(struct interface_info *ifi, struct option_data *options)
 	struct dhcp_packet *packet = &ifi->recv_packet;
 	char ifname[IF_NAMESIZE];
 	struct client_lease *lease;
-	char *pretty, *buf;
+	char *pretty, *buf, *name;
 	int i;
 
 	lease = calloc(1, sizeof(struct client_lease));
@@ -1200,8 +1200,8 @@ packet_to_lease(struct interface_info *ifi, struct option_data *options)
 	for (i = 0; i < DHO_COUNT; i++) {
 		if (options[i].len == 0)
 			continue;
-		if (!unknown_ok && strncmp("option-",
-		    dhcp_options[i].name, 7) != 0) {
+		name = code_to_name(i);
+		if (!unknown_ok && strncmp("option-", name, 7) != 0) {
 			log_warnx("lease declined: unknown option %d", i);
 			goto decline;
 		}
@@ -1215,7 +1215,7 @@ packet_to_lease(struct interface_info *ifi, struct option_data *options)
 			    options[i].len);
 			if (buf == NULL || !res_hnok_list(buf)) {
 				log_warnx("Ignoring %s in offer: invalid host "
-				    "name(s)", dhcp_options[i].name);
+				    "name(s)", name);
 				continue;
 			}
 			break;
@@ -1228,7 +1228,7 @@ packet_to_lease(struct interface_info *ifi, struct option_data *options)
 			 */
 			if (!res_hnok_list(pretty)) {
 				log_warnx("Ignoring %s in offer: invalid host "
-				    "name(s)", dhcp_options[i].name);
+				    "name(s)", name);
 				continue;
 			}
 			break;
@@ -1236,7 +1236,7 @@ packet_to_lease(struct interface_info *ifi, struct option_data *options)
 		case DHO_NIS_DOMAIN:
 			if (!res_hnok(pretty)) {
 				log_warnx("Ignoring %s in offer: invalid host "
-				    "name", dhcp_options[i].name);
+				    "name", name);
 				continue;
 			}
 			break;
@@ -1253,8 +1253,9 @@ packet_to_lease(struct interface_info *ifi, struct option_data *options)
 	 */
 	for (i = 0; i < config->required_option_count; i++) {
 		if (!lease->options[config->required_options[i]].len) {
+			name = code_to_name(i);
 			log_warnx("lease declined: %s required but missing",
-			    dhcp_options[i].name);
+			    name);
 			goto decline;
 		}
 	}
@@ -1829,12 +1830,12 @@ append_statement(char *string, size_t sz, char *s1, char *s2)
 }
 
 char *
-lease_as_string(char *name, char *type, struct client_lease *lease)
+lease_as_string(char *ifname, char *type, struct client_lease *lease)
 {
 	static char string[8192];
 	char timebuf[27];	/* to hold "6 2017/04/08 05:47:50 UTC;" */
 	struct option_data *opt;
-	char *buf;
+	char *buf, *name;
 	size_t rslt;
 	int i;
 
@@ -1844,7 +1845,7 @@ lease_as_string(char *name, char *type, struct client_lease *lease)
 	strlcat(string, " {\n", sizeof(string));
 	strlcat(string, BOOTP_LEASE(lease) ? "  bootp;\n" : "", sizeof(string));
 
-	buf = pretty_print_string(name, strlen(name), 1);
+	buf = pretty_print_string(ifname, strlen(ifname), 1);
 	if (buf == NULL)
 		return (NULL);
 	append_statement(string, sizeof(string), "  interface ", buf);
@@ -1880,12 +1881,13 @@ lease_as_string(char *name, char *type, struct client_lease *lease)
 		opt = &lease->options[i];
 		if (opt->len == 0)
 			continue;
+		name = code_to_name(i);
 
 		buf = pretty_print_option(i, opt, 1);
 		if (buf == NULL)
 			return (NULL);
 		strlcat(string, "  option ", sizeof(string));
-		strlcat(string, dhcp_options[i].name, sizeof(string));
+		strlcat(string, name, sizeof(string));
 		append_statement(string, sizeof(string), " ", buf);
 	}
 
@@ -2367,10 +2369,7 @@ apply_ignore_list(char *ignore_list)
 		if (*p == '\0')
 			continue;
 
-		for (i = 1; i < DHO_END; i++)
-			if (!strcasecmp(dhcp_options[i].name, p))
-				break;
-
+		i = name_to_code(p);
 		if (i == DHO_END) {
 			log_info("Invalid option name: '%s'", p);
 			return;
diff --git a/sbin/dhclient/dhcpd.h b/sbin/dhclient/dhcpd.h
index dbdee34dc1d..45d504b706d 100644
--- a/sbin/dhclient/dhcpd.h
+++ b/sbin/dhclient/dhcpd.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: dhcpd.h,v 1.208 2017/07/08 00:36:10 krw Exp $	*/
+/*	$OpenBSD: dhcpd.h,v 1.209 2017/07/08 20:38:31 krw Exp $	*/
 
 /*
  * Copyright (c) 2004 Henning Brauer <henning@openbsd.org>
@@ -44,11 +44,6 @@
 #define	INTERNALSIG	INT_MAX
 #define DB_TIMEFMT	"%w %Y/%m/%d %T UTC"
 
-struct option {
-	char *name;
-	char *format;
-};
-
 struct option_data {
 	unsigned int	 len;
 	uint8_t		*data;
@@ -176,6 +171,9 @@ char *pretty_print_domain_search(unsigned char *, size_t);
 char *pretty_print_string(unsigned char *, size_t, int);
 char *pretty_print_classless_routes(unsigned char *, size_t);
 struct option_data *unpack_options(struct dhcp_packet *);
+char *code_to_name(int);
+char *code_to_format(int);
+int name_to_code(char *);
 
 /* conflex.c */
 extern int lexline, lexchar;
@@ -213,9 +211,6 @@ int interface_status(char *);
 void get_hw_address(struct interface_info *);
 void sendhup(void);
 
-/* tables.c */
-extern const struct option dhcp_options[DHO_COUNT];
-
 /* dhclient.c */
 extern char *path_dhclient_conf;
 extern char *path_dhclient_db;
diff --git a/sbin/dhclient/options.c b/sbin/dhclient/options.c
index 1a2c5723d54..c0309e94fe9 100644
--- a/sbin/dhclient/options.c
+++ b/sbin/dhclient/options.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: options.c,v 1.96 2017/07/08 00:36:10 krw Exp $	*/
+/*	$OpenBSD: options.c,v 1.97 2017/07/08 20:38:31 krw Exp $	*/
 
 /* DHCP options parsing and reassembly. */
 
@@ -65,6 +65,338 @@ int parse_option_buffer(struct option_data *, unsigned char *, int);
 int expand_search_domain_name(unsigned char *, size_t, int *, unsigned char *);
 
 /*
+ * DHCP Option names, formats and codes, from RFC1533.
+ *
+ * Format codes:
+ *
+ * e - end of data
+ * I - IP address
+ * l - 32-bit signed integer
+ * L - 32-bit unsigned integer
+ * S - 16-bit unsigned integer
+ * B - 8-bit unsigned integer
+ * t - ASCII text
+ * f - flag (true or false)
+ * A - array of whatever precedes (e.g., IA means array of IP addresses)
+ * C - CIDR description
+ */
+
+static const struct {
+	char *name;
+	char *format;
+} dhcp_options[DHO_COUNT] = {
+	/*   0 */ { "pad", "" },
+	/*   1 */ { "subnet-mask", "I" },
+	/*   2 */ { "time-offset", "l" },
+	/*   3 */ { "routers", "IA" },
+	/*   4 */ { "time-servers", "IA" },
+	/*   5 */ { "ien116-name-servers", "IA" },
+	/*   6 */ { "domain-name-servers", "IA" },
+	/*   7 */ { "log-servers", "IA" },
+	/*   8 */ { "cookie-servers", "IA" },
+	/*   9 */ { "lpr-servers", "IA" },
+	/*  10 */ { "impress-servers", "IA" },
+	/*  11 */ { "resource-location-servers", "IA" },
+	/*  12 */ { "host-name", "t" },
+	/*  13 */ { "boot-size", "S" },
+	/*  14 */ { "merit-dump", "t" },
+	/*  15 */ { "domain-name", "t" },
+	/*  16 */ { "swap-server", "I" },
+	/*  17 */ { "root-path", "t" },
+	/*  18 */ { "extensions-path", "t" },
+	/*  19 */ { "ip-forwarding", "f" },
+	/*  20 */ { "non-local-source-routing", "f" },
+	/*  21 */ { "policy-filter", "IIA" },
+	/*  22 */ { "max-dgram-reassembly", "S" },
+	/*  23 */ { "default-ip-ttl", "B" },
+	/*  24 */ { "path-mtu-aging-timeout", "L" },
+	/*  25 */ { "path-mtu-plateau-table", "SA" },
+	/*  26 */ { "interface-mtu", "S" },
+	/*  27 */ { "all-subnets-local", "f" },
+	/*  28 */ { "broadcast-address", "I" },
+	/*  29 */ { "perform-mask-discovery", "f" },
+	/*  30 */ { "mask-supplier", "f" },
+	/*  31 */ { "router-discovery", "f" },
+	/*  32 */ { "router-solicitation-address", "I" },
+	/*  33 */ { "static-routes", "IIA" },
+	/*  34 */ { "trailer-encapsulation", "f" },
+	/*  35 */ { "arp-cache-timeout", "L" },
+	/*  36 */ { "ieee802-3-encapsulation", "f" },
+	/*  37 */ { "default-tcp-ttl", "B" },
+	/*  38 */ { "tcp-keepalive-interval", "L" },
+	/*  39 */ { "tcp-keepalive-garbage", "f" },
+	/*  40 */ { "nis-domain", "t" },
+	/*  41 */ { "nis-servers", "IA" },
+	/*  42 */ { "ntp-servers", "IA" },
+	/*  43 */ { "vendor-encapsulated-options", "X" },
+	/*  44 */ { "netbios-name-servers", "IA" },
+	/*  45 */ { "netbios-dd-server", "IA" },
+	/*  46 */ { "netbios-node-type", "B" },
+	/*  47 */ { "netbios-scope", "t" },
+	/*  48 */ { "font-servers", "IA" },
+	/*  49 */ { "x-display-manager", "IA" },
+	/*  50 */ { "dhcp-requested-address", "I" },
+	/*  51 */ { "dhcp-lease-time", "L" },
+	/*  52 */ { "dhcp-option-overload", "B" },
+	/*  53 */ { "dhcp-message-type", "B" },
+	/*  54 */ { "dhcp-server-identifier", "I" },
+	/*  55 */ { "dhcp-parameter-request-list", "BA" },
+	/*  56 */ { "dhcp-message", "t" },
+	/*  57 */ { "dhcp-max-message-size", "S" },
+	/*  58 */ { "dhcp-renewal-time", "L" },
+	/*  59 */ { "dhcp-rebinding-time", "L" },
+	/*  60 */ { "dhcp-class-identifier", "t" },
+	/*  61 */ { "dhcp-client-identifier", "X" },
+	/*  62 */ { NULL, NULL },
+	/*  63 */ { NULL, NULL },
+	/*  64 */ { "nisplus-domain", "t" },
+	/*  65 */ { "nisplus-servers", "IA" },
+	/*  66 */ { "tftp-server-name", "t" },
+	/*  67 */ { "bootfile-name", "t" },
+	/*  68 */ { "mobile-ip-home-agent", "IA" },
+	/*  69 */ { "smtp-server", "IA" },
+	/*  70 */ { "pop-server", "IA" },
+	/*  71 */ { "nntp-server", "IA" },
+	/*  72 */ { "www-server", "IA" },
+	/*  73 */ { "finger-server", "IA" },
+	/*  74 */ { "irc-server", "IA" },
+	/*  75 */ { "streettalk-server", "IA" },
+	/*  76 */ { "streettalk-directory-assistance-server", "IA" },
+	/*  77 */ { "user-class", "t" },
+	/*  78 */ { NULL, NULL },
+	/*  79 */ { NULL, NULL },
+	/*  80 */ { NULL, NULL },
+	/*  81 */ { NULL, NULL },
+	/*  82 */ { "relay-agent-information", "X" },
+	/*  83 */ { NULL, NULL },
+	/*  84 */ { NULL, NULL },
+	/*  85 */ { "nds-servers", "IA" },
+	/*  86 */ { "nds-tree-name", "X" },
+	/*  87 */ { "nds-context", "X" },
+	/*  88 */ { NULL, NULL },
+	/*  89 */ { NULL, NULL },
+	/*  90 */ { NULL, NULL },
+	/*  91 */ { NULL, NULL },
+	/*  92 */ { NULL, NULL },
+	/*  93 */ { NULL, NULL },
+	/*  94 */ { NULL, NULL },
+	/*  95 */ { NULL, NULL },
+	/*  96 */ { NULL, NULL },
+	/*  97 */ { NULL, NULL },
+	/*  98 */ { NULL, NULL },
+	/*  99 */ { NULL, NULL },
+	/* 100 */ { NULL, NULL },
+	/* 101 */ { NULL, NULL },
+	/* 102 */ { NULL, NULL },
+	/* 103 */ { NULL, NULL },
+	/* 104 */ { NULL, NULL },
+	/* 105 */ { NULL, NULL },
+	/* 106 */ { NULL, NULL },
+	/* 107 */ { NULL, NULL },
+	/* 108 */ { NULL, NULL },
+	/* 109 */ { NULL, NULL },
+	/* 110 */ { NULL, NULL },
+	/* 111 */ { NULL, NULL },
+	/* 112 */ { NULL, NULL },
+	/* 113 */ { NULL, NULL },
+	/* 114 */ { NULL, NULL },
+	/* 115 */ { NULL, NULL },
+	/* 116 */ { NULL, NULL },
+	/* 117 */ { NULL, NULL },
+	/* 118 */ { NULL, NULL },
+	/* 119 */ { "domain-search", "X" },
+	/* 120 */ { NULL, NULL },
+	/* 121 */ { "classless-static-routes", "CIA" },
+	/* 122 */ { NULL, NULL },
+	/* 123 */ { NULL, NULL },
+	/* 124 */ { NULL, NULL },
+	/* 125 */ { NULL, NULL },
+	/* 126 */ { NULL, NULL },
+	/* 127 */ { NULL, NULL },
+	/* 128 */ { NULL, NULL },
+	/* 129 */ { NULL, NULL },
+	/* 130 */ { NULL, NULL },
+	/* 131 */ { NULL, NULL },
+	/* 132 */ { NULL, NULL },
+	/* 133 */ { NULL, NULL },
+	/* 134 */ { NULL, NULL },
+	/* 135 */ { NULL, NULL },
+	/* 136 */ { NULL, NULL },
+	/* 137 */ { NULL, NULL },
+	/* 138 */ { NULL, NULL },
+	/* 139 */ { NULL, NULL },
+	/* 140 */ { NULL, NULL },
+	/* 141 */ { NULL, NULL },
+	/* 142 */ { NULL, NULL },
+	/* 143 */ { NULL, NULL },
+	/* 144 */ { "tftp-config-file", "t" },
+	/* 145 */ { NULL, NULL },
+	/* 146 */ { NULL, NULL },
+	/* 147 */ { NULL, NULL },
+	/* 148 */ { NULL, NULL },
+	/* 149 */ { NULL, NULL },
+	/* 150 */ { "voip-configuration-server", "IA" },
+	/* 151 */ { NULL, NULL },
+	/* 152 */ { NULL, NULL },
+	/* 153 */ { NULL, NULL },
+	/* 154 */ { NULL, NULL },
+	/* 155 */ { NULL, NULL },
+	/* 156 */ { NULL, NULL },
+	/* 157 */ { NULL, NULL },
+	/* 158 */ { NULL, NULL },
+	/* 159 */ { NULL, NULL },
+	/* 160 */ { NULL, NULL },
+	/* 161 */ { NULL, NULL },
+	/* 162 */ { NULL, NULL },
+	/* 163 */ { NULL, NULL },
+	/* 164 */ { NULL, NULL },
+	/* 165 */ { NULL, NULL },
+	/* 166 */ { NULL, NULL },
+	/* 167 */ { NULL, NULL },
+	/* 168 */ { NULL, NULL },
+	/* 169 */ { NULL, NULL },
+	/* 170 */ { NULL, NULL },
+	/* 171 */ { NULL, NULL },
+	/* 172 */ { NULL, NULL },
+	/* 173 */ { NULL, NULL },
+	/* 174 */ { NULL, NULL },
+	/* 175 */ { NULL, NULL },
+	/* 176 */ { NULL, NULL },
+	/* 177 */ { NULL, NULL },
+	/* 178 */ { NULL, NULL },
+	/* 179 */ { NULL, NULL },
+	/* 180 */ { NULL, NULL },
+	/* 181 */ { NULL, NULL },
+	/* 182 */ { NULL, NULL },
+	/* 183 */ { NULL, NULL },
+	/* 184 */ { NULL, NULL },
+	/* 185 */ { NULL, NULL },
+	/* 186 */ { NULL, NULL },
+	/* 187 */ { NULL, NULL },
+	/* 188 */ { NULL, NULL },
+	/* 189 */ { NULL, NULL },
+	/* 190 */ { NULL, NULL },
+	/* 191 */ { NULL, NULL },
+	/* 192 */ { NULL, NULL },
+	/* 193 */ { NULL, NULL },
+	/* 194 */ { NULL, NULL },
+	/* 195 */ { NULL, NULL },
+	/* 196 */ { NULL, NULL },
+	/* 197 */ { NULL, NULL },
+	/* 198 */ { NULL, NULL },
+	/* 199 */ { NULL, NULL },
+	/* 200 */ { NULL, NULL },
+	/* 201 */ { NULL, NULL },
+	/* 202 */ { NULL, NULL },
+	/* 203 */ { NULL, NULL },
+	/* 204 */ { NULL, NULL },
+	/* 205 */ { NULL, NULL },
+	/* 206 */ { NULL, NULL },
+	/* 207 */ { NULL, NULL },
+	/* 208 */ { NULL, NULL },
+	/* 209 */ { NULL, NULL },
+	/* 210 */ { NULL, NULL },
+	/* 211 */ { NULL, NULL },
+	/* 212 */ { NULL, NULL },
+	/* 213 */ { NULL, NULL },
+	/* 214 */ { NULL, NULL },
+	/* 215 */ { NULL, NULL },
+	/* 216 */ { NULL, NULL },
+	/* 217 */ { NULL, NULL },
+	/* 218 */ { NULL, NULL },
+	/* 219 */ { NULL, NULL },
+	/* 220 */ { NULL, NULL },
+	/* 221 */ { NULL, NULL },
+	/* 222 */ { NULL, NULL },
+	/* 223 */ { NULL, NULL },
+	/* 224 */ { NULL, NULL },
+	/* 225 */ { NULL, NULL },
+	/* 226 */ { NULL, NULL },
+	/* 227 */ { NULL, NULL },
+	/* 228 */ { NULL, NULL },
+	/* 229 */ { NULL, NULL },
+	/* 230 */ { NULL, NULL },
+	/* 231 */ { NULL, NULL },
+	/* 232 */ { NULL, NULL },
+	/* 233 */ { NULL, NULL },
+	/* 234 */ { NULL, NULL },
+	/* 235 */ { NULL, NULL },
+	/* 236 */ { NULL, NULL },
+	/* 237 */ { NULL, NULL },
+	/* 238 */ { NULL, NULL },
+	/* 239 */ { NULL, NULL },
+	/* 240 */ { NULL, NULL },
+	/* 241 */ { NULL, NULL },
+	/* 242 */ { NULL, NULL },
+	/* 243 */ { NULL, NULL },
+	/* 244 */ { NULL, NULL },
+	/* 245 */ { NULL, NULL },
+	/* 246 */ { NULL, NULL },
+	/* 247 */ { NULL, NULL },
+	/* 248 */ { NULL, NULL },
+	/* 249 */ { "classless-ms-static-routes", "CIA" },
+	/* 250 */ { NULL, NULL },
+	/* 251 */ { NULL, NULL },
+	/* 252 */ { "autoproxy-script", "t" },
+	/* 253 */ { NULL, NULL },
+	/* 254 */ { NULL, NULL },
+	/* 255 */ { "option-end", "e" },
+};
+
+char *
+code_to_name(int code)
+{
+	static char	 unknown[11];	/* "option-NNN" */
+	int		 ret;
+
+	if (code < 0 || code >= DHO_COUNT)
+		return "";
+
+	if (dhcp_options[code].name != NULL)
+		return dhcp_options[code].name;
+
+	ret = snprintf(unknown, sizeof(unknown), "option-%d", code);
+	if (ret == -1 || ret >= (int)sizeof(unknown))
+		return "";
+
+	return unknown;
+}
+
+int
+name_to_code(char *name)
+{
+	char	unknown[11];	/* "option-NNN" */
+	int	code, ret;
+
+	for (code = 1; code < DHO_END; code++) {
+		if (dhcp_options[code].name == NULL) {
+			ret = snprintf(unknown, sizeof(unknown), "option-%d",
+			    code);
+			if (ret == -1 || ret >= (int)sizeof(unknown))
+				return DHO_END;
+			if (strcasecmp(unknown, name) == 0)
+				return code;
+		} else if (strcasecmp(dhcp_options[code].name, name) == 0) {
+			return code;
+		}
+	}
+
+	return DHO_END;
+}
+
+char *
+code_to_format(int code)
+{
+	if (code < 0 || code >= DHO_COUNT)
+		return "";
+
+	if (dhcp_options[code].format == NULL)
+		return "X";
+
+	return dhcp_options[code].format;
+}
+
+/*
  * Parse options out of the specified buffer, storing addresses of
  * option values in options. Return 0 if errors, 1 if not.
  */
@@ -72,8 +404,9 @@ int
 parse_option_buffer(struct option_data *options, unsigned char *buffer,
     int length)
 {
-	unsigned char *s, *t, *end = buffer + length;
-	int len, code;
+	unsigned char	*s, *t, *end = buffer + length;
+	char		*name, *fmt;
+	int		 len, code;
 
 	for (s = buffer; *s != DHO_END && s < end; ) {
 		code = s[0];
@@ -84,6 +417,9 @@ parse_option_buffer(struct option_data *options, unsigned char *buffer,
 			continue;
 		}
 
+		name = code_to_name(code);
+		fmt = code_to_format(code);
+
 		/*
 		 * All options other than DHO_PAD and DHO_END have a one-byte
 		 * length field. It could be 0! Make sure that the length byte
@@ -95,12 +431,11 @@ parse_option_buffer(struct option_data *options, unsigned char *buffer,
 				; /* option data is all there. */
 			} else {
 				log_warnx("option %s (%d) larger than buffer.",
-				    dhcp_options[code].name, len);
+				    name, len);
 				return (0);
 			}
 		} else {
-			log_warnx("option %s has no length field.",
-			    dhcp_options[code].name);
+			log_warnx("option %s has no length field.", name);
 			return (0);
 		}
 
@@ -111,7 +446,7 @@ parse_option_buffer(struct option_data *options, unsigned char *buffer,
 		 * a trailing NULL; however, the receiver of such options
 		 * MUST be prepared to delete trailing nulls if they exist."
 		 */
-		if (dhcp_options[code].format[0] == 't') {
+		if (fmt[0] == 't') {
 			while (len > 0 && s[len + 1] == '\0')
 				len--;
 		}
@@ -123,7 +458,7 @@ parse_option_buffer(struct option_data *options, unsigned char *buffer,
 		if (!options[code].data) {
 			if (!(t = calloc(1, len + 1)))
 				fatalx("Can't allocate storage for option %s.",
-				    dhcp_options[code].name);
+				    name);
 			/*
 			 * Copy and NUL-terminate the option (in case
 			 * it's an ASCII string).
@@ -140,7 +475,7 @@ parse_option_buffer(struct option_data *options, unsigned char *buffer,
 			t = calloc(1, len + options[code].len + 1);
 			if (!t)
 				fatalx("Can't expand storage for option %s.",
-				    dhcp_options[code].name);
+				    name);
 			memcpy(t, options[code].data, options[code].len);
 			memcpy(t + options[code].len, &s[2], len);
 			options[code].len += len;
@@ -419,7 +754,7 @@ pretty_print_option(unsigned int code, struct option_data *option,
 	struct in_addr	 foo;
 	unsigned char	*data = option->data;
 	unsigned char	*dp = data;
-	char		*op = optbuf, *buf;
+	char		*op = optbuf, *buf, *name, *fmt;
 	int		 hunksize = 0, numhunk = -1, numelem = 0;
 	int		 i, j, k, opleft = sizeof(optbuf);
 	int		 len = option->len;
@@ -455,26 +790,26 @@ pretty_print_option(unsigned int code, struct option_data *option,
 		break;
 	}
 
+	name = code_to_name(code);
+	fmt = code_to_format(code);
+
 	/* Figure out the size of the data. */
-	for (i = 0; dhcp_options[code].format[i]; i++) {
+	for (i = 0; fmt[i]; i++) {
 		if (!numhunk) {
 			log_warnx("%s: Excess information in format string: "
-			    "%s", dhcp_options[code].name,
-			    &(dhcp_options[code].format[i]));
+			    "%s", name, &fmt[i]);
 			goto done;
 		}
 		numelem++;
-		fmtbuf[i] = dhcp_options[code].format[i];
-		switch (dhcp_options[code].format[i]) {
+		fmtbuf[i] = fmt[i];
+		switch (fmt[i]) {
 		case 'A':
 			--numelem;
 			fmtbuf[i] = 0;
 			numhunk = 0;
 			if (hunksize == 0) {
 				log_warnx("%s: no size indicator before A"
-				    " in format string: %s",
-				    dhcp_options[code].name,
-				    dhcp_options[code].format);
+				    " in format string: %s", name, fmt);
 				goto done;
 			}
 			break;
@@ -512,23 +847,22 @@ pretty_print_option(unsigned int code, struct option_data *option,
 		case 'e':
 			break;
 		default:
-			log_warnx("%s: garbage in format string: %s",
-			    dhcp_options[code].name,
-			    &(dhcp_options[code].format[i]));
+			log_warnx("%s: garbage in format string: %s", name,
+			    &fmt[i]);
 			goto done;
 		}
 	}
 
 	/* Check for too few bytes. */
 	if (hunksize > len) {
-		log_warnx("%s: expecting at least %d bytes; got %d",
-		    dhcp_options[code].name, hunksize, len);
+		log_warnx("%s: expecting at least %d bytes; got %d", name,
+		    hunksize, len);
 		goto done;
 	}
 	/* Check for too many bytes. */
 	if (numhunk == -1 && hunksize < len) {
-		log_warnx("%s: expecting only %d bytes: got %d",
-		    dhcp_options[code].name, hunksize, len);
+		log_warnx("%s: expecting only %d bytes: got %d", name,
+		    hunksize, len);
 		goto done;
 	}
 
@@ -537,8 +871,8 @@ pretty_print_option(unsigned int code, struct option_data *option,
 		numhunk = len / hunksize;
 	/* See if we got an exact number of hunks. */
 	if (numhunk > 0 && numhunk * hunksize != len) {
-		log_warnx("%s: expecting %d bytes: got %d",
-		    dhcp_options[code].name, numhunk * hunksize, len);
+		log_warnx("%s: expecting %d bytes: got %d", name,
+		    numhunk * hunksize, len);
 		goto done;
 	}