From 03e948b1af5e17259fb1da0acff9902604ac1b5f Mon Sep 17 00:00:00 2001
From: Nick Bowler <nbowler@draconx.ca>
Date: Fri, 5 Jun 2009 01:29:08 -0400
Subject: [PATCH] Implement lookups in the name table.

---
 libupkg.c | 120 ++++++++++++++++++++++++++++++++++++++++++++++++++----
 upkg.c    |   5 +++
 upkg.h    |   1 +
 3 files changed, 119 insertions(+), 7 deletions(-)

diff --git a/libupkg.c b/libupkg.c
index 617aefa..b932d86 100644
--- a/libupkg.c
+++ b/libupkg.c
@@ -1,18 +1,47 @@
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 
 #include "upkg.h"
 #include "pack.h"
 
+struct upkg_name {
+	unsigned long index, flags;
+	char *name;
+};
 
 struct upkg_private {
 	FILE *f;
 
+	struct upkg_name *names;
 
 	unsigned long name_offset, export_offset, import_offset;
 	unsigned char guid[16];
 };
 
+static int namecmp(const void *_a, const void *_b, void *_pkg)
+{
+	const struct upkg_name *a = _a, *b = _b;
+	if (a->index < b->index)
+		return -1;
+	if (a->index > b->index)
+		return -1;
+	return 0;
+}
+
+static long decode_index(unsigned char *bytes)
+{
+	long val = 0;
+	size_t i = 1;
+
+	val += bytes[0] & 0x3f;
+	if (bytes[0] & 0x40) do {
+		val += bytes[i] & 0x7f;
+	} while (bytes[i] & 0x80 && i < 5);
+
+	return bytes[0] & 0x80 ? -val : val;
+}
+
 static struct upkg *init_upkg(unsigned char hdr[static UPKG_HDR_SIZE])
 {
 	struct upkg *pkg;
@@ -42,38 +71,115 @@ static struct upkg *init_upkg(unsigned char hdr[static UPKG_HDR_SIZE])
 	return pkg;
 }
 
+static int pkg_init_names(struct upkg *pkg)
+{
+	size_t rc, nbuf = 0, len;
+	unsigned long index = 0;
+	char buf[512];
+
+	if (fseek(pkg->priv->f, pkg->priv->name_offset, SEEK_SET) != 0)
+		return -1;
+
+	pkg->priv->names = malloc(pkg->name_count * sizeof *pkg->priv->names);
+	if (!pkg->priv->names)
+		return -1;
+
+	while (index < pkg->name_count) {
+		struct upkg_name *name = &pkg->priv->names[index];
+		name->index = index;
+
+		/* Read some data into buffer. */
+		if (!feof(pkg->priv->f)) {
+			rc = fread(buf+nbuf, 1, sizeof buf-nbuf, pkg->priv->f);
+			if (rc == 0)
+				goto err;
+			nbuf += rc;
+		}
+
+		if (pkg->version >= 64) {
+			len = buf[0];
+			if (nbuf <= len + 4 || buf[len])
+				goto err;
+			name->name = malloc(len);
+			if (!name->name)
+				goto err;
+			memcpy(name->name, buf+1, len);
+			name->flags = unpack_32_le(buf+len+1);
+
+			nbuf -= len + 5;
+			memmove(buf, buf+len+5, nbuf);
+			index++;
+		} else {
+			abort();
+		}
+	}
+
+	return 0;
+err:
+	free(pkg->priv->names);
+	return -1;
+}
+
 struct upkg *upkg_fopen(const char *path)
 {
 	unsigned char hdr_buf[UPKG_HDR_SIZE];
 	struct upkg *pkg;
 	FILE *f;
-	
+
 	if (!(f = fopen(path, "rb"))) {
 		return NULL;
 	}
 	if (fread(hdr_buf, sizeof hdr_buf, 1, f) != 1) {
-		goto err;
+		goto err1;
 	}
 	if (unpack_32_le(hdr_buf) != UPKG_HDR_MAGIC) {
-		goto err;
+		goto err1;
 	}
 
 	/* Initialize package structure. */
 	pkg = init_upkg(hdr_buf);
 	if (!pkg) {
-		goto err;
+		goto err1;
 	}
 	pkg->priv->f = f;
 
+	if (pkg_init_names(pkg) != 0) {
+		goto err2;
+	}
+
 	return pkg;
-err:
+err2:
+	free(pkg->priv);
+	free(pkg);
+err1:
 	fclose(f);
 	return NULL;
 }
 
 int upkg_close(struct upkg *pkg)
 {
-	if (pkg->priv->f)
-		return fclose(pkg->priv->f);
+	int rc = 0;
+
+	if (pkg->priv->f) {
+		rc = fclose(pkg->priv->f);
+
+		for (unsigned i = 0; i < pkg->name_count; i++) {
+			free(pkg->priv->names[i].name);
+		}
+		free(pkg->priv->names);
+
+		return rc;
+	}
+
+	free(pkg->priv);
+	free(pkg);
+
 	return 0;
 }
+
+const char *upkg_get_name(struct upkg *pkg, unsigned long idx)
+{
+	if (idx >= pkg->name_count)
+		return 0;
+	return pkg->priv->names[idx].name;
+}
diff --git a/upkg.c b/upkg.c
index 3cfd727..970de56 100644
--- a/upkg.c
+++ b/upkg.c
@@ -36,9 +36,14 @@ int main(int argc, char **argv)
 
 	printf("Version: %u\n",  pkg->version);
 	printf("License: %u\n",  pkg->license);
+
 	printf("Flags:   %lx\n", pkg->flags);
 	print_upkg_flags("\t", pkg->flags);
+
 	printf("Names:   %zu\n", pkg->name_count);
+	for (unsigned long i = 0; i < pkg->name_count; i++) {
+		printf("\t%s\n", upkg_get_name(pkg, i));
+	}
 
 	upkg_close(pkg);
 	return 0;
diff --git a/upkg.h b/upkg.h
index c4d582d..f20f18e 100644
--- a/upkg.h
+++ b/upkg.h
@@ -22,5 +22,6 @@ struct upkg {
 
 struct upkg *upkg_fopen(const char *path);
 int upkg_close(struct upkg *pkg);
+const char *upkg_get_name(struct upkg *pkg, unsigned long idx);
 
 #endif
-- 
2.43.2