From 20cb252b483c6797a77219be3faa6513e35adf51 Mon Sep 17 00:00:00 2001
From: Patrick McDermott <patrick.mcdermott@libiquity.com>
Date: Fri, 14 Apr 2023 15:00:58 -0400
Subject: Eliminate magic numbers

---
diff --git a/src/gzip.c b/src/gzip.c
index dc22ee0..6e9528f 100644
--- a/src/gzip.c
+++ b/src/gzip.c
@@ -21,6 +21,9 @@
 #include <zlib.h>
 #include "defs.h"
 #include "gzip.h"
+#include "ustar.h"
+
+#define OPKG_OPK_GZIP_WINDOW_BITS_ (15 + 16)
 
 struct opkg_opk_gzip {
 	int      (*read)(void *, char **, size_t *);
@@ -46,7 +49,7 @@ opkg_opk_gzip_init(int (*read)(void *, char **, size_t *), void *user_data)
 	gzip->stream.zalloc   = Z_NULL;
 	gzip->stream.zfree    = Z_NULL;
 	gzip->stream.opaque   = Z_NULL;
-	if (inflateInit2(&gzip->stream, 15 + 16) != Z_OK) {
+	if (inflateInit2(&gzip->stream, OPKG_OPK_GZIP_WINDOW_BITS_) != Z_OK) {
 		free(gzip);
 		return NULL;
 	}
@@ -58,7 +61,7 @@ int
 opkg_opk_gzip_read(struct opkg_opk_gzip *gzip, void *record)
 {
 	gzip->stream.next_out  = record;
-	gzip->stream.avail_out = 512;
+	gzip->stream.avail_out = OPKG_OPK_USTAR_RECORD_SIZE;
 
 	for (;;) {
 		if (gzip->stream.avail_in == 0) {
diff --git a/src/main.c b/src/main.c
index 79ed68c..25659b6 100644
--- a/src/main.c
+++ b/src/main.c
@@ -23,9 +23,11 @@
 #include "gzip.h"
 #include "ustar.h"
 
+#define OPKG_OPK_MAIN_FILE_BUFFER_SIZE_ 8192
+
 struct _opkg_opk_main_file {
 	FILE *file;
-	char  buffer[8192];
+	char  buffer[OPKG_OPK_MAIN_FILE_BUFFER_SIZE_];
 };
 
 static int
@@ -34,7 +36,8 @@ _opkg_opk_main_file_read(void *user_data, char **buffer, size_t *size)
 	struct _opkg_opk_main_file *file = user_data;
 
 	*buffer = file->buffer;
-	*size   = fread(file->buffer, 1, 8192, file->file);
+	*size   = fread(file->buffer, 1, OPKG_OPK_MAIN_FILE_BUFFER_SIZE_,
+			file->file);
 	if (feof(file->file)) {
 		return OPKG_OPK_END;
 	} else if (ferror(file->file) || *size == 0) {
diff --git a/src/ustar.c b/src/ustar.c
index 4805880..f403524 100644
--- a/src/ustar.c
+++ b/src/ustar.c
@@ -25,6 +25,8 @@
 #include "gzip.h"
 #include "ustar.h"
 
+#define OPKG_OPK_USTAR_NUM_BASE_ 8
+
 struct _opkg_opk_ustar_header {
 	unsigned char name     [100];
 	unsigned char mode       [8];
@@ -70,7 +72,7 @@ static int
 _opkg_opk_ustar_next(struct opkg_opk_ustar *ustar,
 		struct _opkg_opk_ustar_header *header)
 {
-	static unsigned char  record[512];
+	static unsigned char  record[OPKG_OPK_USTAR_RECORD_SIZE];
 	       char          *size_end;
 
 	switch (opkg_opk_gzip_read(ustar->gzip, header)) {
@@ -80,8 +82,8 @@ _opkg_opk_ustar_next(struct opkg_opk_ustar *ustar,
 		case OPKG_OPK_ERROR:
 			return OPKG_OPK_ERROR;
 	}
-	memset(record, 0, 512);
-	if (memcmp(header, record, 512) == 0) {
+	memset(record, 0, OPKG_OPK_USTAR_RECORD_SIZE);
+	if (memcmp(header, record, OPKG_OPK_USTAR_RECORD_SIZE) == 0) {
 		return OPKG_OPK_END;
 	}
 	if (memcmp(header->magic, "ustar", strlen("ustar")) != 0) {
@@ -89,7 +91,7 @@ _opkg_opk_ustar_next(struct opkg_opk_ustar *ustar,
 	}
 
 	ustar->data_size_remaining = strtol((char *) header->size, &size_end,
-			8);
+			OPKG_OPK_USTAR_NUM_BASE_);
 	if (*size_end != '\0') {
 		return OPKG_OPK_ERROR;
 	}
@@ -111,8 +113,8 @@ opkg_opk_ustar_list(struct opkg_opk_ustar *ustar,
 	if (record.prefix[0] != '\0') {
 		sprintf(member->name, "%s/%s", record.prefix, record.name);
 	} else {
-		memcpy(member->name, record.name, 100);
-		member->name[100] = '\0';
+		memcpy(member->name, record.name, sizeof(record.name));
+		member->name[sizeof(record.name)] = '\0';
 	}
 
 	while (ustar->data_size_remaining > 0) {
@@ -129,7 +131,7 @@ int
 opkg_opk_ustar_seek(struct opkg_opk_ustar *ustar, const char *member)
 {
 	static struct _opkg_opk_ustar_header  record;
-	static unsigned char                  name[257];
+	static unsigned char                  name[OPKG_OPK_USTAR_NAME_MAX_LEN];
 	       int                            ret;
 
 	for (;;) {
@@ -142,8 +144,8 @@ opkg_opk_ustar_seek(struct opkg_opk_ustar *ustar, const char *member)
 			sprintf((char *) name, "%s/%s", record.prefix,
 					record.name);
 		} else {
-			memcpy(name, record.name, 100);
-			name[100] = '\0';
+			memcpy(name, record.name, sizeof(record.name));
+			name[sizeof(record.name)] = '\0';
 		}
 
 		if (strcmp((char *) name, member) == 0) {
@@ -178,11 +180,11 @@ opkg_opk_ustar_read(struct opkg_opk_ustar *ustar, char *buffer, size_t *size)
 			return OPKG_OPK_ERROR;
 	}
 
-	if (ustar->data_size_remaining >= 512) {
+	if (ustar->data_size_remaining >= OPKG_OPK_USTAR_RECORD_SIZE) {
 		if (size != NULL) {
-			*size = 512;
+			*size = OPKG_OPK_USTAR_RECORD_SIZE;
 		}
-		ustar->data_size_remaining -= 512;
+		ustar->data_size_remaining -= OPKG_OPK_USTAR_RECORD_SIZE;
 	} else {
 		if (size != NULL) {
 			*size = ustar->data_size_remaining;
diff --git a/src/ustar.h b/src/ustar.h
index ccb10a2..596f598 100644
--- a/src/ustar.h
+++ b/src/ustar.h
@@ -20,10 +20,14 @@
 #ifndef OPKG_OPK_USTAR_H_
 #define OPKG_OPK_USTAR_H_
 
+#define OPKG_OPK_USTAR_RECORD_SIZE  512
+#define OPKG_OPK_USTAR_NAME_MAX_LEN 257  /* prefix[155] + '/' + name[100] + '\0'
+                                          */
+
 struct opkg_opk_ustar;
 
 struct opkg_opk_ustar_member {
-	char name[257];  /* prefix[155] + '/' + name[100] + '\0' */
+	char name[OPKG_OPK_USTAR_NAME_MAX_LEN];
 };
 
 struct opkg_opk_ustar *
--
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