From ad83b0f167f3e65a2aa04cf358d1f995f1241a3c Mon Sep 17 00:00:00 2001 From: David Oberhollenzer Date: Sun, 16 Jun 2019 12:36:37 +0200 Subject: sqfs2tar: cleanup tar header generation - use struct stat instead of tree node - compact some of the code Signed-off-by: David Oberhollenzer --- tar/sqfs2tar.c | 8 ++- tar/tar.h | 7 +- tar/write_header.c | 184 +++++++++++++++++++++++++---------------------------- 3 files changed, 96 insertions(+), 103 deletions(-) diff --git a/tar/sqfs2tar.c b/tar/sqfs2tar.c index f7f7e71..1be1b7e 100644 --- a/tar/sqfs2tar.c +++ b/tar/sqfs2tar.c @@ -105,7 +105,8 @@ static int terminate_archive(void) static int write_tree_dfs(fstree_t *fs, tree_node_t *n, data_reader_t *data) { - char *name; + char *name, *target; + struct stat sb; int ret; if (n->parent != NULL || !S_ISDIR(n->mode)) { @@ -117,7 +118,10 @@ static int write_tree_dfs(fstree_t *fs, tree_node_t *n, data_reader_t *data) assert(canonicalize_name(name) == 0); - ret = write_tar_header(STDOUT_FILENO, fs, n, name); + fstree_node_stat(fs, n, &sb); + + target = S_ISLNK(sb.st_mode) ? n->data.slink_target : NULL; + ret = write_tar_header(STDOUT_FILENO, &sb, name, target); free(name); if (ret < 0) diff --git a/tar/tar.h b/tar/tar.h index 11af6ee..35c4fe0 100644 --- a/tar/tar.h +++ b/tar/tar.h @@ -2,7 +2,8 @@ #ifndef TAR_H #define TAR_H -#include "fstree.h" +#include +#include typedef struct { char name[100]; @@ -53,8 +54,8 @@ typedef struct { Returns < 0 on failure, > 0 if cannot encode, 0 on success. Prints error/warning messages to stderr. */ -int write_tar_header(int fd, const fstree_t *fs, const tree_node_t *n, - const char *name); +int write_tar_header(int fd, const struct stat *sb, const char *name, + const char *slink_target); /* calcuate and skip the zero padding */ int skip_padding(int fd, uint64_t size); diff --git a/tar/write_header.c b/tar/write_header.c index 9073056..80db327 100644 --- a/tar/write_header.c +++ b/tar/write_header.c @@ -17,41 +17,6 @@ static void write_octal(char *dst, unsigned int value, int digits) memcpy(dst, temp, strlen(temp)); } -static void init_header(tar_header_t *hdr, const fstree_t *fs, - const tree_node_t *n) -{ - memset(hdr, 0, sizeof(*hdr)); - - memcpy(hdr->magic, TAR_MAGIC, strlen(TAR_MAGIC)); - memcpy(hdr->version, TAR_VERSION, strlen(TAR_VERSION)); - - write_octal(hdr->mode, n->mode & ~S_IFMT, 6); - write_octal(hdr->uid, n->uid, 6); - write_octal(hdr->gid, n->gid, 6); - write_octal(hdr->size, 0, 11); - write_octal(hdr->mtime, fs->default_mtime, 11); - write_octal(hdr->devmajor, 0, 6); - write_octal(hdr->devminor, 0, 6); - - sprintf(hdr->uname, "%u", n->uid); - sprintf(hdr->gname, "%u", n->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 int name_to_tar_header(tar_header_t *hdr, const char *path) { size_t len = strlen(path); @@ -80,22 +45,70 @@ static int name_to_tar_header(tar_header_t *hdr, const char *path) return 0; } -static bool need_pax_header(const tree_node_t *n, const char *name) +static void init_header(tar_header_t *hdr, const struct stat *sb, + const char *name, const char *slink_target) { - tar_header_t temp; + 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); - if (n->uid > 0777777 || n->gid > 0777777) + 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(n->mode) && n->data.file->size > 077777777777UL) + if (S_ISREG(sb->st_mode) && sb->st_size > 077777777777L) return true; - if (S_ISLNK(n->mode)) { - if (strlen(n->data.slink_target) >= sizeof(temp.linkname)) - return true; - } + if (S_ISLNK(sb->st_mode) && sb->st_size >= (off_t)sizeof(tmp.linkname)) + return true; - if (name_to_tar_header(&temp, name)) + if (name_to_tar_header(&tmp, name)) return true; return false; @@ -120,48 +133,41 @@ static char *write_pax_entry(char *dst, const char *key, const char *value) return dst + len; } -static int write_pax_header(int fd, const fstree_t *fs, const tree_node_t *n, - const char *name) +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(&hdr, 0, sizeof(hdr)); - - sprintf(hdr.name, "pax%lu", pax_hdr_counter); - memcpy(hdr.magic, TAR_MAGIC, strlen(TAR_MAGIC)); - memcpy(hdr.version, TAR_VERSION, strlen(TAR_VERSION)); - write_octal(hdr.mode, 0644, 6); - write_octal(hdr.uid, 0, 6); - write_octal(hdr.gid, 0, 6); - write_octal(hdr.mtime, 0, 11); - write_octal(hdr.devmajor, 0, 6); - write_octal(hdr.devminor, 0, 6); - sprintf(hdr.uname, "%u", 0); - sprintf(hdr.gname, "%u", 0); + 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; - sprintf(temp, "%u", n->uid); ptr = write_pax_entry(ptr, "uid", temp); ptr = write_pax_entry(ptr, "uname", temp); - sprintf(temp, "%u", fs->default_mtime); + sprintf(temp, "%lu", sb->st_mtime); ptr = write_pax_entry(ptr, "mtime", temp); - sprintf(temp, "%u", n->gid); + 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(n->mode)) { - ptr = write_pax_entry(ptr, "linkpath", n->data.slink_target); - } else if (S_ISREG(n->mode)) { - sprintf(temp, "%lu", n->data.file->size); + 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); } @@ -190,48 +196,30 @@ fail_trunc: return -1; } -int write_tar_header(int fd, const fstree_t *fs, const tree_node_t *n, - const char *name) +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(n, name)) { - if (write_pax_header(fd, fs, n, name)) + if (need_pax_header(sb, name)) { + if (write_pax_header(fd, sb, name, slink_target)) return -1; - init_header(&hdr, fs, n); - sprintf(hdr.name, "pax%lu_data", pax_hdr_counter++); - } else { - init_header(&hdr, fs, n); - name_to_tar_header(&hdr, name); + sprintf(buffer, "pax%lu_data", pax_hdr_counter++); + name = buffer; } - switch (n->mode & S_IFMT) { - case S_IFCHR: - case S_IFBLK: - write_octal(hdr.devmajor, major(n->data.devno), 6); - write_octal(hdr.devminor, minor(n->data.devno), 6); - hdr.typeflag = S_ISBLK(n->mode) ? TAR_TYPE_BLOCKDEV : - TAR_TYPE_CHARDEV; - break; - case S_IFLNK: - if (strlen(n->data.slink_target) < sizeof(hdr.linkname)) - strcpy(hdr.linkname, n->data.slink_target); + init_header(&hdr, sb, name, slink_target); - hdr.typeflag = TAR_TYPE_SLINK; - break; - case S_IFREG: - write_octal(hdr.size, n->data.file->size & 077777777777UL, 11); - hdr.typeflag = TAR_TYPE_FILE; - break; - case S_IFDIR: - hdr.typeflag = TAR_TYPE_DIR; - break; - case S_IFIFO: - hdr.typeflag = TAR_TYPE_FIFO; - break; + 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; -- cgit v1.2.3