From: Roy Marples <roy@marples.name>
Date: Sun, 29 Jun 2008 18:28:19 +0000 (+0000)
Subject: Save a few bytes by treating some strings like DHCP options, having the first byte... 
X-Git-Tag: v4.0.2~265
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=abc5592709affc9ec3f88ec786b624b69ee9f28f;p=thirdparty%2Fdhcpcd.git

Save a few bytes by treating some strings like DHCP options, having the first byte as the length.
---

diff --git a/client.c b/client.c
index 1e6b0e50..59321090 100644
--- a/client.c
+++ b/client.c
@@ -465,7 +465,7 @@ client_setup(struct if_state *state, const struct options *options)
 	struct interface *iface = state->interface;
 	struct dhcp_lease *lease = &state->lease;
 	struct in_addr addr;
-	size_t duid_len = 0;
+	size_t len = 0;
 #ifdef ENABLE_DUID
 	unsigned char *duid = NULL;
 	uint32_t ul;
@@ -524,54 +524,55 @@ client_setup(struct if_state *state, const struct options *options)
 
 	if (*options->clientid) {
 		/* Attempt to see if the ClientID is a hardware address */
-		iface->clientid_len = hwaddr_aton(NULL, options->clientid);
-		if (iface->clientid_len) {
-			iface->clientid = xmalloc(iface->clientid_len);
-			hwaddr_aton(iface->clientid, options->clientid);
+		if ((len = hwaddr_aton(NULL, options->clientid))) {
+			iface->clientid = xmalloc(len + 1);
+			iface->clientid[0] = len;
+			hwaddr_aton(iface->clientid + 1, options->clientid);
 		} else {
 			/* Nope, so mark it as-is */
-			iface->clientid_len = strlen(options->clientid) + 1;
-			iface->clientid = xmalloc(iface->clientid_len);
-			*iface->clientid = '\0';
-			memcpy(iface->clientid + 1,
-			       options->clientid, iface->clientid_len - 1);
+			len = strlen(options->clientid) + 1;
+			iface->clientid = xmalloc(len + 1);
+			iface->clientid[0] = len;
+			iface->clientid[1] = 0; /* string */
+			memcpy(iface->clientid + 2, options->clientid, len);
 		}
 	} else if (options->options & DHCPCD_CLIENTID) {
 #ifdef ENABLE_DUID
 		if (options->options & DHCPCD_DUID) {
 			duid = xmalloc(DUID_LEN);
-			duid_len = get_duid(duid, iface);
-			if (duid_len == 0)
+			if ((len = get_duid(duid, iface)) == 0)
 				logger(LOG_ERR, "get_duid: %s",
 				       strerror(errno));
 		}
 
-		if (duid_len > 0) {
+		if (len > 0) {
 			logger(LOG_INFO, "DUID = %s",
-			       hwaddr_ntoa(duid, duid_len));
+			       hwaddr_ntoa(duid, len));
 
-			iface->clientid_len = duid_len + 5;
-			iface->clientid = xmalloc(iface->clientid_len);
-			*iface->clientid = 255; /* RFC 4361 */
+			len += 5;
+			iface->clientid = xmalloc(len);
+			iface->clientid[0] = len;
+			iface->clientid[1] = 255; /* RFC 4361 */
 
 			/* IAID is 4 bytes, so if the iface name is 4 bytes
 			 * use it */
 			if (strlen(iface->name) == 4) {
-				memcpy(iface->clientid + 1, iface->name, 4);
+				memcpy(iface->clientid + 2, iface->name, 4);
 			} else {
 				/* Name isn't 4 bytes, so use the index */
 				ul = htonl(if_nametoindex(iface->name));
-				memcpy(iface->clientid + 1, &ul, 4);
+				memcpy(iface->clientid + 2, &ul, 4);
 			}
 
-			memcpy(iface->clientid + 5, duid, duid_len);
+			memcpy(iface->clientid + 6, duid, len);
 			free(duid);
 		}
 #endif
-		if (duid_len == 0) {
-			iface->clientid_len = iface->hwlen + 1;
-			iface->clientid = xmalloc(iface->clientid_len);
-			*iface->clientid = iface->family;
+		if (len == 0) {
+			len = iface->hwlen + 1;
+			iface->clientid = xmalloc(len);
+			iface->clientid[0] = len;
+			iface->clientid[1] = iface->family;
 			memcpy(iface->clientid + 1, iface->hwaddr, iface->hwlen);
 		}
 	}
diff --git a/dhcp.c b/dhcp.c
index c8abd0fb..e2e3a8f0 100644
--- a/dhcp.c
+++ b/dhcp.c
@@ -775,26 +775,23 @@ make_message(struct dhcp_message **message,
 		p += 2;
 	}
 
-	if (iface->clientid_len > 0) {
+	if (iface->clientid[0]) {
 		*p++ = DHCP_CLIENTID;
-		*p++ = iface->clientid_len;
-		memcpy(p, iface->clientid, iface->clientid_len);
-		p+= iface->clientid_len;
+		memcpy(p, iface->clientid, iface->clientid[0] + 1);
+		p += iface->clientid[0] + 1;
 	}
 
 	if (type != DHCP_DECLINE && type != DHCP_RELEASE) {
-		if (options->userclass_len > 0) {
+		if (options->userclass[0]) {
 			*p++ = DHCP_USERCLASS;
-			*p++ = options->userclass_len;
-			memcpy(p, &options->userclass, options->userclass_len);
-			p += options->userclass_len;
+			memcpy(p, options->userclass, options->userclass[0] + 1);
+			p += options->userclass[0] + 1;
 		}
 
-		if (*options->classid > 0) {
+		if (options->classid[0]) {
 			*p++ = DHCP_CLASSID;
-			*p++ = l = strlen(options->classid);
-			memcpy(p, options->classid, l);
-			p += l;
+			memcpy(p, options->classid, options->classid[0] + 1);
+			p += options->classid[0] + 1;
 		}
 	}
 
diff --git a/dhcpcd.c b/dhcpcd.c
index 2c125f27..693d3923 100644
--- a/dhcpcd.c
+++ b/dhcpcd.c
@@ -205,9 +205,7 @@ add_environ(struct options *options, const char *value, int uniq)
 static int
 parse_option(int opt, char *oarg, struct options *options)
 {
-	static int userclasses = 0;
 	int i;
-	int j;
 	char *p;
 	size_t s;
 	size_t olen;
@@ -236,14 +234,16 @@ parse_option(int opt, char *oarg, struct options *options)
 	case 'i':
 		if (!oarg) {
 			*options->classid = '\0';
-		} else if (olen >= CLASS_ID_MAX_LEN) {
+		} else if (olen >= CLASSID_MAX_LEN) {
 			logger(LOG_ERR,
 			       "`%s' too long for ClassID string, max is %d",
-			       oarg, CLASS_ID_MAX_LEN);
+			       oarg, CLASSID_MAX_LEN);
 			return -1;
-		} else
-			strlcpy(options->classid, oarg,
+		} else {
+			options->classid[0] = strlen(oarg);
+			strlcpy(options->classid + 1, oarg,
 				sizeof(options->classid));
+		}
 		break;
 	case 'l':
 		if (*oarg == '-') {
@@ -314,19 +314,16 @@ parse_option(int opt, char *oarg, struct options *options)
 		}
 		break;
 	case 'u':
-		j = 0;
-		for (i = 0; i < userclasses; i++)
-			j += (int)options->userclass[j] + 1;
-		if (j + 1 + olen >= USERCLASS_MAX_LEN) {
+		if (options->userclass[0] + olen + 1 >= USERCLASS_MAX_LEN) {
 			logger(LOG_ERR,
 			       "userclass overrun, max is %d",
 			       USERCLASS_MAX_LEN);
 			return -1;
 		}
-		userclasses++;
-		memcpy(options->userclass + j + 1, oarg, olen);
-		options->userclass[j] = olen;
-		options->userclass_len += olen + 1;
+		p = options->userclass + options->userclass[0] + 1;
+		*p++ = olen;
+		memcpy(p, oarg, olen);
+		options->userclass[0] += olen + 1;
 		break;
 	case 'A':
 		options->options &= ~DHCPCD_ARP;
@@ -371,18 +368,20 @@ parse_option(int opt, char *oarg, struct options *options)
 		break;
 	case 'I':
 		if (oarg) {
-			if (olen >= CLIENT_ID_MAX_LEN) {
+			if (olen >= CLIENTID_MAX_LEN) {
 				logger(LOG_ERR, "`%s' is too long for"
 				       " ClientID, max is %d",
-				       oarg, CLIENT_ID_MAX_LEN);
+				       oarg, CLIENTID_MAX_LEN);
 				return -1;
 			}
-			if (strlcpy(options->clientid, oarg,
-				    sizeof(options->clientid)) == 0) {
+			if (strlcpy(options->clientid + 1, oarg,
+				    CLIENTID_MAX_LEN) == 0)
+			{
 				/* empty string disabled duid */
 				options->options &= ~DHCPCD_DUID;
 				options->options &= ~DHCPCD_CLIENTID;
-			}
+			} else
+				options->clientid[0] = strlen(oarg);
 		} else {
 			options->clientid[0] = '\0';
 			options->options &= ~DHCPCD_DUID;
@@ -448,8 +447,8 @@ main(int argc, char **argv)
 
 	options = xzalloc(sizeof(*options));
 	options->script = SCRIPT;
-	snprintf(options->classid, CLASS_ID_MAX_LEN, "%s %s",
-		 PACKAGE, VERSION);
+	options->classid[0] = snprintf(options->classid + 1, CLASSID_MAX_LEN,
+				       "%s %s", PACKAGE, VERSION);
 
 	options->options |= DHCPCD_GATEWAY | DHCPCD_DAEMONISE | DHCPCD_CLIENTID;
 #ifdef ENABLE_ARP
diff --git a/dhcpcd.h b/dhcpcd.h
index ac1a651a..7b1ee396 100644
--- a/dhcpcd.h
+++ b/dhcpcd.h
@@ -41,8 +41,8 @@
 #define DEFAULT_TIMEOUT		30
 #define DEFAULT_LEASETIME	3600        /* 1 hour */
 
-#define CLASS_ID_MAX_LEN	48
-#define CLIENT_ID_MAX_LEN	48
+#define CLASSID_MAX_LEN		48
+#define CLIENTID_MAX_LEN	48
 #define USERCLASS_MAX_LEN	255
 
 #ifdef THERE_IS_NO_FORK 
@@ -72,12 +72,11 @@ struct options {
 	char interface[IF_NAMESIZE];
 	char hostname[MAXHOSTNAMELEN];
 	int fqdn;
-	char classid[CLASS_ID_MAX_LEN];
-	char clientid[CLIENT_ID_MAX_LEN];
-	char userclass[USERCLASS_MAX_LEN];
+	char classid[CLASSID_MAX_LEN + 1];
+	char clientid[CLIENTID_MAX_LEN + 1];
+	char userclass[USERCLASS_MAX_LEN + 1];
 	uint8_t reqmask[256 / 8];
 	uint8_t nomask[256 / 8];
-	size_t userclass_len;
 	uint32_t leasetime;
 	time_t timeout;
 	int metric;
diff --git a/net.h b/net.h
index aef09e33..5f98b526 100644
--- a/net.h
+++ b/net.h
@@ -119,7 +119,6 @@ struct interface
 	time_t start_uptime;
 
 	unsigned char *clientid;
-	size_t clientid_len;
 };
 
 uint32_t get_netmask(uint32_t);