Split generic tar code off to static library

Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>

1 files changed, 0 insertions, 415 deletions

diff --git a/tar/read_header.c b/tar/read_header.c
deleted file mode 100644
index bdb2d20..0000000
--- a/tar/read_header.c
+++ /dev/null
@@ -1,415 +0,0 @@
-/* SPDX-License-Identifier: GPL-3.0-or-later */
-#include "util.h"
-#include "tar.h"
-
-#include <sys/sysmacros.h>
-#include <string.h>
-#include <stdlib.h>
-#include <ctype.h>
-#include <stdio.h>
-
-enum {
-	PAX_SIZE = 0x001,
-	PAX_UID = 0x002,
-	PAX_GID = 0x004,
-	PAX_DEV_MAJ = 0x008,
-	PAX_DEV_MIN = 0x010,
-	PAX_NAME = 0x020,
-	PAX_SLINK_TARGET = 0x040,
-	PAX_ATIME = 0x080,
-	PAX_MTIME = 0x100,
-	PAX_CTIME = 0x200,
-};
-
-static int read_octal(const char *str, int digits, uint64_t *out)
-{
-	uint64_t result = 0;
-
-	while (digits > 0 && *str >= '0' && *str <= '7') {
-		if (result > 0x1FFFFFFFFFFFFFFFUL) {
-			fputs("numeric overflow parsing tar header\n", stderr);
-			return -1;
-		}
-
-		result = (result << 3) | (*(str++) - '0');
-		--digits;
-	}
-
-	*out = result;
-	return 0;
-}
-
-static int read_binary(const char *str, int digits, uint64_t *out)
-{
-	uint64_t x, result = 0;
-
-	while (digits > 0) {
-		if (result > 0x00FFFFFFFFFFFFFFUL) {
-			fputs("numeric overflow parsing tar header\n", stderr);
-			return -1;
-		}
-
-		x = *((const unsigned char *)str++);
-		result = (result << 8) | x;
-		--digits;
-	}
-
-	*out = result;
-	return 0;
-}
-
-static int read_number(const char *str, int digits, uint64_t *out)
-{
-	if (*((unsigned char *)str) & 0x80) {
-		if (read_binary(str, digits, out))
-			return -1;
-		*out &= 0x7FFFFFFFFFFFFFFF;
-		return 0;
-	}
-
-	return read_octal(str, digits, out);
-}
-
-static bool is_zero_block(const tar_header_t *hdr)
-{
-	const unsigned char *ptr = (const unsigned char *)hdr;
-
-	return ptr[0] == '\0' && memcmp(ptr, ptr + 1, sizeof(*hdr) - 1) == 0;
-}
-
-static bool is_checksum_valid(const tar_header_t *hdr)
-{
-	unsigned int chksum = 0;
-	tar_header_t copy;
-	uint64_t ref;
-	size_t i;
-
-	if (read_octal(hdr->chksum, sizeof(hdr->chksum), &ref))
-		return false;
-
-	memcpy(&copy, hdr, sizeof(*hdr));
-	memset(copy.chksum, ' ', sizeof(copy.chksum));
-
-	for (i = 0; i < sizeof(copy); ++i)
-		chksum += ((unsigned char *)&copy)[i];
-
-	return chksum == ref;
-}
-
-static bool is_magic_valid(const tar_header_t *hdr)
-{
-	if (memcmp(hdr->magic, TAR_MAGIC, sizeof(hdr->magic)) != 0)
-		return false;
-
-	if (memcmp(hdr->version, TAR_VERSION, sizeof(hdr->version)) != 0)
-		return false;
-
-	return true;
-}
-
-static int pax_read_decimal(const char *str, uint64_t *out)
-{
-	uint64_t result = 0;
-
-	while (*str >= '0' && *str <= '9') {
-		if (result > 0xFFFFFFFFFFFFFFFFUL / 10) {
-			fputs("numeric overflow parsing pax header\n", stderr);
-			return -1;
-		}
-
-		result = (result * 10) + (*(str++) - '0');
-	}
-
-	*out = result;
-	return 0;
-}
-
-static int read_pax_header(int fd, uint64_t entsize, unsigned int *set_by_pax,
-			   tar_header_decoded_t *out)
-{
-	char *buffer, *line;
-	uint64_t field;
-	ssize_t ret;
-	uint64_t i;
-
-	buffer = malloc(entsize + 1);
-	if (buffer == NULL)
-		goto fail_errno;
-
-	ret = read_retry(fd, buffer, entsize);
-	if (ret < 0)
-		goto fail_errno;
-	if ((size_t)ret < entsize)
-		goto fail_eof;
-
-	if (skip_padding(fd, entsize))
-		goto fail;
-
-	buffer[entsize] = '\0';
-
-	for (i = 0; i < entsize; ++i) {
-		while (i < entsize && isspace(buffer[i]))
-			++i;
-		while (i < entsize && isdigit(buffer[i]))
-			++i;
-		while (i < entsize && isspace(buffer[i]))
-			++i;
-		if (i >= entsize)
-			break;
-
-		line = buffer + i;
-
-		while (i < entsize && buffer[i] != '\n')
-			++i;
-
-		buffer[i] = '\0';
-
-		if (!strncmp(line, "uid=", 4)) {
-			pax_read_decimal(line + 4, &field);
-			out->sb.st_uid = field;
-			*set_by_pax |= PAX_UID;
-		} else if (!strncmp(line, "gid=", 4)) {
-			pax_read_decimal(line + 4, &field);
-			out->sb.st_gid = field;
-			*set_by_pax |= PAX_GID;
-		} else if (!strncmp(line, "path=", 5)) {
-			free(out->name);
-			out->name = strdup(line + 5);
-			if (out->name == NULL)
-				goto fail_errno;
-			*set_by_pax |= PAX_NAME;
-		} else if (!strncmp(line, "size=", 5)) {
-			pax_read_decimal(line + 5, &field);
-			out->sb.st_size = field;
-			*set_by_pax |= PAX_SIZE;
-		} else if (!strncmp(line, "linkpath=", 9)) {
-			free(out->link_target);
-			out->link_target = strdup(line + 9);
-			if (out->link_target == NULL)
-				goto fail_errno;
-			*set_by_pax |= PAX_SLINK_TARGET;
-		} else if (!strncmp(line, "atime=", 6)) {
-			pax_read_decimal(line + 6, &field);
-			out->sb.st_atime = field;
-			*set_by_pax |= PAX_ATIME;
-		} else if (!strncmp(line, "mtime=", 6)) {
-			pax_read_decimal(line + 6, &field);
-			out->sb.st_mtime = field;
-			*set_by_pax |= PAX_MTIME;
-		} else if (!strncmp(line, "ctime=", 6)) {
-			pax_read_decimal(line + 6, &field);
-			out->sb.st_ctime = field;
-			*set_by_pax |= PAX_CTIME;
-		}
-	}
-
-	free(buffer);
-	return 0;
-fail_errno:
-	perror("reading pax header");
-	goto fail;
-fail_eof:
-	fputs("reading pax header: unexpected end of file\n", stderr);
-	goto fail;
-fail:
-	free(buffer);
-	return -1;
-}
-
-static int decode_header(const tar_header_t *hdr, unsigned int set_by_pax,
-			 tar_header_decoded_t *out)
-{
-	uint64_t field;
-	size_t count;
-
-	if (!(set_by_pax & PAX_NAME)) {
-		if (hdr->prefix[0] == '\0') {
-			count = strlen(hdr->name) + 1;
-			count += strlen(hdr->prefix) + 1;
-
-			out->name = malloc(count);
-
-			if (out->name != NULL) {
-				sprintf(out->name, "%s/%s",
-					hdr->prefix, hdr->name);
-			}
-		} else {
-			out->name = strdup(hdr->name);
-		}
-
-		if (out->name == NULL) {
-			perror("decoding filename");
-			return -1;
-		}
-	}
-
-	if (!(set_by_pax & PAX_SIZE)) {
-		if (read_number(hdr->size, sizeof(hdr->size), &field))
-			return -1;
-		out->sb.st_size = field;
-	}
-
-	if (!(set_by_pax & PAX_UID)) {
-		if (read_number(hdr->uid, sizeof(hdr->uid), &field))
-			return -1;
-		out->sb.st_uid = field;
-	}
-
-	if (!(set_by_pax & PAX_GID)) {
-		if (read_number(hdr->gid, sizeof(hdr->gid), &field))
-			return -1;
-		out->sb.st_gid = field;
-	}
-
-	if (!(set_by_pax & PAX_DEV_MAJ)) {
-		if (read_number(hdr->devmajor, sizeof(hdr->devmajor), &field))
-			return -1;
-
-		out->sb.st_rdev = makedev(field, minor(out->sb.st_rdev));
-	}
-
-	if (!(set_by_pax & PAX_DEV_MIN)) {
-		if (read_number(hdr->devminor, sizeof(hdr->devminor), &field))
-			return -1;
-
-		out->sb.st_rdev = makedev(major(out->sb.st_rdev), field);
-	}
-
-	if (!(set_by_pax & PAX_MTIME)) {
-		if (read_number(hdr->mtime, sizeof(hdr->mtime), &field))
-			return -1;
-		out->sb.st_mtime = field;
-	}
-
-	if (!(set_by_pax & PAX_ATIME))
-		out->sb.st_atime = out->sb.st_mtime;
-
-	if (!(set_by_pax & PAX_CTIME))
-		out->sb.st_ctime = out->sb.st_mtime;
-
-	if (read_octal(hdr->mode, sizeof(hdr->mode), &field))
-		return -1;
-
-	out->sb.st_mode = field & 07777;
-
-	if (hdr->typeflag == TAR_TYPE_LINK ||
-	    hdr->typeflag == TAR_TYPE_SLINK) {
-		if (!(set_by_pax & PAX_SLINK_TARGET)) {
-			out->link_target = strdup(hdr->linkname);
-			if (out->link_target == NULL) {
-				perror("decoding symlink target");
-				return -1;
-			}
-		}
-	}
-
-	out->unknown_record = false;
-
-	switch (hdr->typeflag) {
-	case '\0':
-	case TAR_TYPE_FILE:
-		out->sb.st_mode |= S_IFREG;
-		break;
-	case TAR_TYPE_LINK:
-		/* XXX: hard links are not support yet */
-		out->sb.st_mode = S_IFLNK | 0777;
-		break;
-	case TAR_TYPE_SLINK:
-		out->sb.st_mode = S_IFLNK | 0777;
-		break;
-	case TAR_TYPE_CHARDEV:
-		out->sb.st_mode |= S_IFCHR;
-		break;
-	case TAR_TYPE_BLOCKDEV:
-		out->sb.st_mode |= S_IFBLK;
-		break;
-	case TAR_TYPE_DIR:
-		out->sb.st_mode |= S_IFDIR;
-		break;
-	case TAR_TYPE_FIFO:
-		out->sb.st_mode |= S_IFIFO;
-		break;
-	default:
-		out->unknown_record = true;
-		break;
-	}
-
-	return 0;
-}
-
-int read_header(int fd, tar_header_decoded_t *out)
-{
-	unsigned int set_by_pax = 0;
-	bool prev_was_zero = false;
-	uint64_t pax_size;
-	tar_header_t hdr;
-	int ret;
-
-	memset(out, 0, sizeof(*out));
-
-	for (;;) {
-		ret = read_retry(fd, &hdr, sizeof(hdr));
-		if (ret == 0)
-			goto out_eof;
-		if (ret < 0)
-			goto fail_errno;
-		if (ret < (int)sizeof(hdr))
-			goto fail_eof;
-
-		if (is_zero_block(&hdr)) {
-			if (prev_was_zero)
-				goto out_eof;
-			prev_was_zero = true;
-			continue;
-		}
-
-		prev_was_zero = false;
-
-		if (!is_magic_valid(&hdr))
-			goto fail_magic;
-
-		if (!is_checksum_valid(&hdr))
-			goto fail_chksum;
-
-		if (hdr.typeflag == TAR_TYPE_PAX) {
-			clear_header(out);
-			if (read_number(hdr.size, sizeof(hdr.size), &pax_size))
-				return -1;
-			set_by_pax = 0;
-			if (read_pax_header(fd, pax_size, &set_by_pax, out))
-				return -1;
-			continue;
-		}
-		break;
-	}
-
-	if (decode_header(&hdr, set_by_pax, out))
-		goto fail;
-
-	return 0;
-out_eof:
-	clear_header(out);
-	return 1;
-fail_errno:
-	perror("reading tar header");
-	goto fail;
-fail_eof:
-	fputs("reading tar header: unexpected end of file\n", stderr);
-	goto fail;
-fail_magic:
-	fputs("input is not a ustar tar archive!\n", stderr);
-	goto fail;
-fail_chksum:
-	fputs("invalid tar header checksum!\n", stderr);
-	goto fail;
-fail:
-	clear_header(out);
-	return -1;
-}
-
-void clear_header(tar_header_decoded_t *hdr)
-{
-	free(hdr->name);
-	free(hdr->link_target);
-	memset(hdr, 0, sizeof(*hdr));
-}