io: make apk_istream_get/read() fail on incomplete read

5 files changed, 44 insertions, 59 deletions

diff --git a/src/adb.c b/src/adb.c
index a4fe612..064cf6b 100644
--- a/src/adb.c
+++ b/src/adb.c
@@ -154,7 +154,7 @@ static int __adb_m_stream(struct adb *db, struct apk_istream *is, uint32_t expec
 	if (IS_ERR(is)) return PTR_ERR(is);
 
 	if (!(expected_schema & ADB_SCHEMA_IMPLIED)) {
-		if ((r = apk_istream_read(is, &db->hdr, sizeof db->hdr)) != sizeof db->hdr) goto err;
+		if ((r = apk_istream_read(is, &db->hdr, sizeof db->hdr)) < 0) goto err;
 		if (db->hdr.magic != htole32(ADB_FORMAT_MAGIC)) {
 			r = -APKE_ADB_HEADER;
 			goto err;
@@ -166,7 +166,7 @@ static int __adb_m_stream(struct adb *db, struct apk_istream *is, uint32_t expec
 	}
 
 	do {
-		r = apk_istream_read(is, &blk, sizeof blk);
+		r = apk_istream_read_max(is, &blk, sizeof blk);
 		if (r == 0) {
 			if (!trusted) r = -APKE_SIGNATURE_UNTRUSTED;
 			else if (!db->adb.ptr) r = -APKE_ADB_BLOCK;
@@ -183,7 +183,7 @@ static int __adb_m_stream(struct adb *db, struct apk_istream *is, uint32_t expec
 			if (!APK_BLOB_IS_NULL(db->adb)) goto bad_msg;
 			db->adb.ptr = malloc(sz);
 			db->adb.len = adb_block_length(&blk);
-			if ((r = apk_istream_read(is, db->adb.ptr, sz)) != sz) goto err;
+			if ((r = apk_istream_read(is, db->adb.ptr, sz)) < 0) goto err;
 			r = cb(db, &blk, apk_istream_from_blob(&seg.is, db->adb));
 			if (r < 0) goto err;
 			continue;
diff --git a/src/apk_io.h b/src/apk_io.h
index d03369e..50464a9 100644
--- a/src/apk_io.h
+++ b/src/apk_io.h
@@ -92,9 +92,10 @@ static inline struct apk_istream *apk_istream_from_file(int atfd, const char *fi
 static inline struct apk_istream *apk_istream_from_file_mmap(int atfd, const char *file) { return __apk_istream_from_file(atfd, file, 1); }
 struct apk_istream *apk_istream_from_fd(int fd);
 struct apk_istream *apk_istream_from_fd_url_if_modified(int atfd, const char *url, time_t since);
-static inline int apk_istream_error(struct apk_istream *is, int err) { if (!is->err) is->err = err; return err; }
+static inline int apk_istream_error(struct apk_istream *is, int err) { if (is->err >= 0 && err) is->err = err; return is->err < 0 ? is->err : 0; }
 apk_blob_t apk_istream_mmap(struct apk_istream *is);
-ssize_t apk_istream_read(struct apk_istream *is, void *ptr, size_t size);
+ssize_t apk_istream_read_max(struct apk_istream *is, void *ptr, size_t size);
+int apk_istream_read(struct apk_istream *is, void *ptr, size_t size);
 void *apk_istream_peek(struct apk_istream *is, size_t len);
 void *apk_istream_get(struct apk_istream *is, size_t len);
 int apk_istream_get_max(struct apk_istream *is, size_t size, apk_blob_t *data);
diff --git a/src/io.c b/src/io.c
index bb5c566..6628c36 100644
--- a/src/io.c
+++ b/src/io.c
@@ -68,7 +68,7 @@ apk_blob_t apk_istream_mmap(struct apk_istream *is)
 	return APK_BLOB_NULL;
 }
 
-ssize_t apk_istream_read(struct apk_istream *is, void *ptr, size_t size)
+ssize_t apk_istream_read_max(struct apk_istream *is, void *ptr, size_t size)
 {
 	ssize_t left = size, r = 0;
 
@@ -100,12 +100,17 @@ ssize_t apk_istream_read(struct apk_istream *is, void *ptr, size_t size)
 		is->end = is->buf + r;
 	}
 
-	if (r < 0) return r;
-	if (size && left == size && !is->err) is->err = 1;
-	if (size == left) return is->err < 0 ? is->err : 0;
+	if (r < 0) return apk_istream_error(is, r);
+	if (left == size) return apk_istream_error(is, (size && !is->err) ? 1 : 0);
 	return size - left;
 }
 
+int apk_istream_read(struct apk_istream *is, void *ptr, size_t size)
+{
+	ssize_t r = apk_istream_read_max(is, ptr, size);
+	return r == size ? 0 : apk_istream_error(is, -APKE_EOF);
+}
+
 static int __apk_istream_fill(struct apk_istream *is)
 {
 	ssize_t sz;
@@ -117,51 +122,46 @@ static int __apk_istream_fill(struct apk_istream *is)
 		memmove(is->buf, is->ptr, sz);
 		is->ptr = is->buf;
 		is->end = is->buf + sz;
-	}
+	} else if (is->end-is->ptr == is->buf_size)
+		return -ENOBUFS;
 
 	sz = is->ops->read(is, is->end, is->buf + is->buf_size - is->end);
-	if (sz <= 0) {
-		is->err = sz ?: 1;
-		return is->err;
-	}
+	if (sz <= 0) return apk_istream_error(is, sz ?: 1);
 	is->end += sz;
 	return 0;
 }
 
 void *apk_istream_peek(struct apk_istream *is, size_t len)
 {
+	int r;
+
 	do {
 		if (is->end - is->ptr >= len) {
 			void *ptr = is->ptr;
 			return ptr;
 		}
-	} while (!__apk_istream_fill(is));
+		r = __apk_istream_fill(is);
+	} while (r == 0);
 
-	if (is->end-is->ptr == is->buf_size)
-		return ERR_PTR(-ENOBUFS);
-	if (is->err > 0)
-		return ERR_PTR(-APKE_EOF);
-	return ERR_PTR(-EIO);
+	return ERR_PTR(r > 0 ? -APKE_EOF : r);
 }
 
 void *apk_istream_get(struct apk_istream *is, size_t len)
 {
 	void *p = apk_istream_peek(is, len);
 	if (!IS_ERR_OR_NULL(p)) is->ptr += len;
+	else apk_istream_error(is, PTR_ERR(p));
 	return p;
 }
 
 int apk_istream_get_max(struct apk_istream *is, size_t max, apk_blob_t *data)
 {
-	if (is->ptr == is->end)
-		__apk_istream_fill(is);
-
+	if (is->ptr == is->end) __apk_istream_fill(is);
 	if (is->ptr != is->end) {
 		*data = APK_BLOB_PTR_LEN((char*)is->ptr, min((size_t)(is->end - is->ptr), max));
 		is->ptr += data->len;
 		return 0;
 	}
-
 	*data = APK_BLOB_NULL;
 	return is->err < 0 ? is->err : -APKE_EOF;
 }
@@ -169,19 +169,17 @@ int apk_istream_get_max(struct apk_istream *is, size_t max, apk_blob_t *data)
 int apk_istream_get_delim(struct apk_istream *is, apk_blob_t token, apk_blob_t *data)
 {
 	apk_blob_t ret = APK_BLOB_NULL, left = APK_BLOB_NULL;
+	int r;
 
 	do {
 		if (apk_blob_split(APK_BLOB_PTR_LEN((char*)is->ptr, is->end - is->ptr), token, &ret, &left))
 			break;
-		if (is->end - is->ptr == is->buf_size) {
-			is->err = -ENOBUFS;
-			break;
-		}
-	} while (!__apk_istream_fill(is));
+		r = __apk_istream_fill(is);
+	} while (r == 0);
 
 	/* Last segment before end-of-file. Return also zero length non-null
 	 * blob if eof comes immediately after the delimiter. */
-	if (is->ptr && is->err > 0)
+	if (is->ptr && r > 0)
 		ret = APK_BLOB_PTR_LEN((char*)is->ptr, is->end - is->ptr);
 
 	if (!APK_BLOB_IS_NULL(ret)) {
@@ -190,8 +188,9 @@ int apk_istream_get_delim(struct apk_istream *is, apk_blob_t token, apk_blob_t *
 		*data = ret;
 		return 0;
 	}
+	if (r < 0) apk_istream_error(is, r);
 	*data = APK_BLOB_NULL;
-	return is->err < 0 ? is->err : -APKE_EOF;
+	return r < 0 ? r : -APKE_EOF;
 }
 
 static void blob_get_meta(struct apk_istream *is, struct apk_file_meta *meta)
@@ -571,21 +570,16 @@ ssize_t apk_stream_copy(struct apk_istream *is, struct apk_ostream *os, size_t s
 apk_blob_t apk_blob_from_istream(struct apk_istream *is, size_t size)
 {
 	void *ptr;
-	ssize_t rsize;
 
 	ptr = malloc(size);
 	if (ptr == NULL)
 		return APK_BLOB_NULL;
 
-	rsize = apk_istream_read(is, ptr, size);
-	if (rsize < 0) {
+	if (apk_istream_read(is, ptr, size) < 0) {
 		free(ptr);
 		return APK_BLOB_NULL;
 	}
-	if (rsize != size)
-		ptr = realloc(ptr, rsize);
-
-	return APK_BLOB_PTR_LEN(ptr, rsize);
+	return APK_BLOB_PTR_LEN(ptr, size);
 }
 
 apk_blob_t apk_blob_from_file(int atfd, const char *file)
diff --git a/src/io_archive.c b/src/io_archive.c
index 1164d7c..ccd512a 100644
--- a/src/io_archive.c
+++ b/src/io_archive.c
@@ -141,7 +141,7 @@ int apk_tar_parse(struct apk_istream *is, apk_archive_entry_parser parser,
 
 	memset(&entry, 0, sizeof(entry));
 	entry.name = buf.name;
-	while ((r = apk_istream_read(is, &buf, 512)) == 512) {
+	while ((r = apk_istream_read_max(is, &buf, 512)) == 512) {
 		if (buf.name[0] == '\0') {
 			if (end) break;
 			end++;
@@ -182,7 +182,7 @@ int apk_tar_parse(struct apk_istream *is, apk_archive_entry_parser parser,
 		switch (buf.typeflag) {
 		case 'L': /* GNU long name extension */
 			if ((r = blob_realloc(&longname, entry.size+1)) != 0 ||
-			    (r = apk_istream_read(is, longname.ptr, entry.size)) != entry.size)
+			    (r = apk_istream_read(is, longname.ptr, entry.size)) < 0)
 				goto err;
 			longname.ptr[entry.size] = 0;
 			entry.name = longname.ptr;
@@ -219,7 +219,7 @@ int apk_tar_parse(struct apk_istream *is, apk_archive_entry_parser parser,
 		case 'x': /* file specific pax header */
 			paxlen = entry.size;
 			if ((r = blob_realloc(&pax, (paxlen + 511) & -512)) != 0 ||
-			    (r = apk_istream_read(is, pax.ptr, paxlen)) != paxlen)
+			    (r = apk_istream_read(is, pax.ptr, paxlen)) < 0)
 				goto err;
 			toskip -= entry.size;
 			break;
@@ -244,14 +244,14 @@ int apk_tar_parse(struct apk_istream *is, apk_archive_entry_parser parser,
 			paxlen = 0;
 		}
 
-		if (toskip && (r = apk_istream_read(is, NULL, toskip)) != toskip)
+		if (toskip && (r = apk_istream_read(is, NULL, toskip)) < 0)
 			goto err;
 	}
 
 	/* Read remaining end-of-archive records, to ensure we read all of
 	 * the file. The underlying istream is likely doing checksumming. */
 	if (r == 512) {
-		while ((r = apk_istream_read(is, &buf, 512)) == 512) {
+		while ((r = apk_istream_read_max(is, &buf, 512)) == 512) {
 			if (buf.name[0] != 0) break;
 		}
 	}
diff --git a/src/package.c b/src/package.c
index dee15eb..fd0104a 100644
--- a/src/package.c
+++ b/src/package.c
@@ -976,23 +976,13 @@ int apk_ipkg_add_script(struct apk_installed_package *ipkg,
 			struct apk_istream *is,
 			unsigned int type, unsigned int size)
 {
-	void *ptr;
-	int r;
-
-	if (type >= APK_SCRIPT_MAX)
-		return -1;
-
-	ptr = malloc(size);
-	r = apk_istream_read(is, ptr, size);
-	if (r < 0) {
-		free(ptr);
-		return r;
-	}
+	apk_blob_t b;
 
-	if (ipkg->script[type].ptr)
-		free(ipkg->script[type].ptr);
-	ipkg->script[type].ptr = ptr;
-	ipkg->script[type].len = size;
+	if (type >= APK_SCRIPT_MAX) return -1;
+	b = apk_blob_from_istream(is, size);
+	if (APK_BLOB_IS_NULL(b)) return -1;
+	if (ipkg->script[type].ptr) free(ipkg->script[type].ptr);
+	ipkg->script[type] = b;
 	return 0;
 }