From 2f172ede7115d0a2730a3b689131042ba559e272 Mon Sep 17 00:00:00 2001 From: David Oberhollenzer Date: Wed, 19 Jun 2019 15:04:17 +0200 Subject: Split generic tar code off to static library Signed-off-by: David Oberhollenzer --- tar/write_header.c | 248 ----------------------------------------------------- 1 file changed, 248 deletions(-) delete mode 100644 tar/write_header.c (limited to 'tar/write_header.c') diff --git a/tar/write_header.c b/tar/write_header.c deleted file mode 100644 index 80db327..0000000 --- a/tar/write_header.c +++ /dev/null @@ -1,248 +0,0 @@ -/* SPDX-License-Identifier: GPL-3.0-or-later */ -#include "util.h" -#include "tar.h" - -#include -#include -#include - -static unsigned long pax_hdr_counter = 0; -static char buffer[4096]; - -static void write_octal(char *dst, unsigned int value, int digits) -{ - char temp[64]; - - sprintf(temp, "%0*o ", digits, value); - memcpy(dst, temp, strlen(temp)); -} - -static int name_to_tar_header(tar_header_t *hdr, const char *path) -{ - size_t len = strlen(path); - const char *ptr; - - if ((len + 1) <= sizeof(hdr->name)) { - memcpy(hdr->name, path, len); - return 0; - } - - for (ptr = path; ; ++ptr) { - ptr = strchr(ptr, '/'); - if (ptr == NULL) - return -1; - - len = ptr - path; - if (len >= sizeof(hdr->prefix)) - continue; - if (strlen(ptr + 1) >= sizeof(hdr->name)) - continue; - break; - } - - memcpy(hdr->prefix, path, ptr - path); - memcpy(hdr->name, ptr + 1, strlen(ptr + 1)); - return 0; -} - -static void init_header(tar_header_t *hdr, const struct stat *sb, - const char *name, const char *slink_target) -{ - memset(hdr, 0, sizeof(*hdr)); - - name_to_tar_header(hdr, name); - memcpy(hdr->magic, TAR_MAGIC, sizeof(hdr->magic)); - memcpy(hdr->version, TAR_VERSION, sizeof(hdr->version)); - write_octal(hdr->mode, sb->st_mode & ~S_IFMT, 6); - write_octal(hdr->uid, sb->st_uid, 6); - write_octal(hdr->gid, sb->st_gid, 6); - write_octal(hdr->mtime, sb->st_mtime, 11); - write_octal(hdr->size, 0, 11); - write_octal(hdr->devmajor, 0, 6); - write_octal(hdr->devminor, 0, 6); - - switch (sb->st_mode & S_IFMT) { - case S_IFREG: - write_octal(hdr->size, sb->st_size & 077777777777L, 11); - break; - case S_IFLNK: - if (sb->st_size < (off_t)sizeof(hdr->linkname)) - strcpy(hdr->linkname, slink_target); - break; - case S_IFCHR: - case S_IFBLK: - write_octal(hdr->devmajor, major(sb->st_rdev), 6); - write_octal(hdr->devminor, minor(sb->st_rdev), 6); - break; - } - - sprintf(hdr->uname, "%u", sb->st_uid); - sprintf(hdr->gname, "%u", sb->st_gid); -} - -static void update_checksum(tar_header_t *hdr) -{ - unsigned int chksum = 0; - size_t i; - - memset(hdr->chksum, ' ', sizeof(hdr->chksum)); - - for (i = 0; i < sizeof(*hdr); ++i) - chksum += ((unsigned char *)hdr)[i]; - - write_octal(hdr->chksum, chksum, 6); - hdr->chksum[6] = '\0'; - hdr->chksum[7] = ' '; -} - -static bool need_pax_header(const struct stat *sb, const char *name) -{ - tar_header_t tmp; - - if (sb->st_uid > 0777777 || sb->st_gid > 0777777) - return true; - - if (S_ISREG(sb->st_mode) && sb->st_size > 077777777777L) - return true; - - if (S_ISLNK(sb->st_mode) && sb->st_size >= (off_t)sizeof(tmp.linkname)) - return true; - - if (name_to_tar_header(&tmp, name)) - return true; - - return false; -} - -static char *write_pax_entry(char *dst, const char *key, const char *value) -{ - size_t i, len, prefix = 0, oldprefix; - - do { - len = prefix + 1 + strlen(key) + 1 + strlen(value) + 1; - - oldprefix = prefix; - prefix = 1; - - for (i = len; i >= 10; i /= 10) - ++prefix; - } while (oldprefix != prefix); - - sprintf(dst, "%zu %s=%s\n", len, key, value); - - return dst + len; -} - -static int write_pax_header(int fd, const struct stat *sb, const char *name, - const char *slink_target) -{ - char temp[64], *ptr; - struct stat fakesb; - tar_header_t hdr; - ssize_t ret; - size_t len; - - memset(buffer, 0, sizeof(buffer)); - memset(&fakesb, 0, sizeof(fakesb)); - fakesb.st_mode = S_IFREG | 0644; - - sprintf(temp, "pax%lu", pax_hdr_counter); - init_header(&hdr, &fakesb, temp, NULL); - hdr.typeflag = TAR_TYPE_PAX; - - sprintf(temp, "%u", sb->st_uid); - ptr = buffer; - ptr = write_pax_entry(ptr, "uid", temp); - ptr = write_pax_entry(ptr, "uname", temp); - - sprintf(temp, "%lu", sb->st_mtime); - ptr = write_pax_entry(ptr, "mtime", temp); - - sprintf(temp, "%u", sb->st_gid); - ptr = write_pax_entry(ptr, "gid", temp); - ptr = write_pax_entry(ptr, "gname", temp); - - ptr = write_pax_entry(ptr, "path", name); - - if (S_ISLNK(sb->st_mode)) { - ptr = write_pax_entry(ptr, "linkpath", slink_target); - } else if (S_ISREG(sb->st_mode)) { - sprintf(temp, "%lu", sb->st_size); - ptr = write_pax_entry(ptr, "size", temp); - } - - len = strlen(buffer); - write_octal(hdr.size, len, 11); - update_checksum(&hdr); - - ret = write_retry(fd, &hdr, sizeof(hdr)); - if (ret < 0) - goto fail_wr; - if ((size_t)ret < sizeof(hdr)) - goto fail_trunc; - - ret = write_retry(fd, buffer, len); - if (ret < 0) - goto fail_wr; - if ((size_t)ret < len) - goto fail_trunc; - - return padd_file(fd, len, 512); -fail_wr: - perror("writing pax header"); - return -1; -fail_trunc: - fputs("writing pax header: truncated write\n", stderr); - return -1; -} - -int write_tar_header(int fd, const struct stat *sb, const char *name, - const char *slink_target) -{ - const char *reason; - tar_header_t hdr; - ssize_t ret; - - if (need_pax_header(sb, name)) { - if (write_pax_header(fd, sb, name, slink_target)) - return -1; - - sprintf(buffer, "pax%lu_data", pax_hdr_counter++); - name = buffer; - } - - init_header(&hdr, sb, name, slink_target); - - switch (sb->st_mode & S_IFMT) { - case S_IFCHR: hdr.typeflag = TAR_TYPE_CHARDEV; break; - case S_IFBLK: hdr.typeflag = TAR_TYPE_BLOCKDEV; break; - case S_IFLNK: hdr.typeflag = TAR_TYPE_SLINK; break; - case S_IFREG: hdr.typeflag = TAR_TYPE_FILE; break; - case S_IFDIR: hdr.typeflag = TAR_TYPE_DIR; break; - case S_IFIFO: hdr.typeflag = TAR_TYPE_FIFO; break; - case S_IFSOCK: - reason = "cannot pack socket"; - goto out_skip; - default: - reason = "unknown type"; - goto out_skip; - } - - update_checksum(&hdr); - - ret = write_retry(fd, &hdr, sizeof(hdr)); - - if (ret < 0) { - perror("writing header record"); - } else if ((size_t)ret < sizeof(hdr)) { - fputs("writing header record: truncated write\n", stderr); - ret = -1; - } else { - ret = 0; - } - - return ret; -out_skip: - fprintf(stderr, "WARNING: skipping '%s' (%s)\n", name, reason); - return 1; -} -- cgit v1.2.3