diff options
author | kientzle <kientzle@FreeBSD.org> | 2004-03-07 00:57:43 +0000 |
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committer | kientzle <kientzle@FreeBSD.org> | 2004-03-07 00:57:43 +0000 |
commit | 76c408916b6540382c7b773b88040e925dd6d20c (patch) | |
tree | b97eaa9edc8a8c2727b2f6fb9fbdd8bba2fe3c37 /lib | |
parent | 6b2e0639b273aae278481d3f011b716b4fffcef7 (diff) | |
download | FreeBSD-src-76c408916b6540382c7b773b88040e925dd6d20c.zip FreeBSD-src-76c408916b6540382c7b773b88040e925dd6d20c.tar.gz |
Recognize hardlinks when reading cpio files.
This doesn't yet address the issue of selective restore
of hardlinked files. With cpio format, it's possible to correctly
restore any linked file; the API doesn't yet fully support this.
(There's no way for the library to inform a client whether or not
there's a file body associated with this entry. The assumption
right now is that "hardlink" entries have no file body.)
Diffstat (limited to 'lib')
-rw-r--r-- | lib/libarchive/archive_read_support_format_cpio.c | 105 |
1 files changed, 100 insertions, 5 deletions
diff --git a/lib/libarchive/archive_read_support_format_cpio.c b/lib/libarchive/archive_read_support_format_cpio.c index 3775d23..73518db 100644 --- a/lib/libarchive/archive_read_support_format_cpio.c +++ b/lib/libarchive/archive_read_support_format_cpio.c @@ -32,8 +32,10 @@ __FBSDID("$FreeBSD$"); #ifdef DMALLOC #include <dmalloc.h> #endif +#include <err.h> #include <errno.h> #include <stdint.h> +#include <stdlib.h> #include <string.h> #include <unistd.h> @@ -55,19 +57,43 @@ struct cpio_header { char c_filesize[11]; }; +struct links_entry { + struct links_entry *next; + struct links_entry *previous; + int links; + dev_t dev; + ino_t ino; + char *name; +}; + +#define CPIO_MAGIC 0x13141516 +struct cpio { + int magic; + struct links_entry *links_head; +}; + static int64_t atol8(const char *, unsigned); static int archive_read_format_cpio_bid(struct archive *); +static int archive_read_format_cpio_cleanup(struct archive *); static int archive_read_format_cpio_read_header(struct archive *, struct archive_entry *); +static void record_hardlink(struct cpio *cpio, struct archive_entry *entry, + const struct stat *st); int archive_read_support_format_cpio(struct archive *a) { + struct cpio *cpio; + + cpio = malloc(sizeof(*cpio)); + memset(cpio, 0, sizeof(*cpio)); + cpio->magic = CPIO_MAGIC; + return (__archive_read_register_format(a, - NULL, + cpio, archive_read_format_cpio_bid, archive_read_format_cpio_read_header, - NULL)); + archive_read_format_cpio_cleanup)); } @@ -100,6 +126,7 @@ archive_read_format_cpio_read_header(struct archive *a, struct archive_entry *entry) { struct stat st; + struct cpio *cpio; size_t bytes; const struct cpio_header *header; const void *h; @@ -107,6 +134,9 @@ archive_read_format_cpio_read_header(struct archive *a, a->archive_format = ARCHIVE_FORMAT_CPIO; a->archive_format_name = "POSIX octet-oriented cpio"; + cpio = *(a->pformat_data); + if (cpio->magic != CPIO_MAGIC) + errx(1, "CPIO data lost? This can't happen.\n"); /* Read fixed-size portion of header. */ bytes = (a->compression_read_ahead)(a, &h, sizeof(struct cpio_header)); @@ -114,7 +144,7 @@ archive_read_format_cpio_read_header(struct archive *a, return (ARCHIVE_FATAL); (a->compression_read_consume)(a, sizeof(struct cpio_header)); - /* Parse out octal fields into struct stat */ + /* Parse out octal fields into struct stat. */ memset(&st, 0, sizeof(st)); header = h; @@ -130,7 +160,7 @@ archive_read_format_cpio_read_header(struct archive *a, /* * Note: entry_bytes_remaining is at least 64 bits and - * therefore gauranteed to be big enough for a 33-bite file + * therefore gauranteed to be big enough for a 33-bit file * size. struct stat.st_size may only be 32 bits, so * assigning there first could lose information. */ @@ -169,11 +199,36 @@ archive_read_format_cpio_read_header(struct archive *a, return (ARCHIVE_EOF); } + /* Detect and record hardlinks to previously-extracted entries. */ + record_hardlink(cpio, entry, &st); + + return (ARCHIVE_OK); +} + +static int +archive_read_format_cpio_cleanup(struct archive *a) +{ + struct cpio *cpio; + + cpio = *(a->pformat_data); + /* Free inode->name map */ + while (cpio->links_head != NULL) { + struct links_entry *lp = cpio->links_head->next; + + if (cpio->links_head->name) + free(cpio->links_head->name); + free(cpio->links_head); + cpio->links_head = lp; + } + + free(cpio); + *(a->pformat_data) = NULL; return (ARCHIVE_OK); } -/* Note that this implementation does not (and should not!) obey +/* + * Note that this implementation does not (and should not!) obey * locale settings; you cannot simply substitute strtol here, since * it does obey locale. */ @@ -199,3 +254,43 @@ atol8(const char *p, unsigned char_cnt) } return (l); } + +static void +record_hardlink(struct cpio *cpio, struct archive_entry *entry, + const struct stat *st) +{ + struct links_entry *le; + + /* + * First look in the list of multiply-linked files. If we've + * already dumped it, convert this entry to a hard link entry. + */ + for (le = cpio->links_head; le; le = le->next) { + if (le->dev == st->st_dev && le->ino == st->st_ino) { + archive_entry_set_hardlink(entry, le->name); + + if (--le->links <= 0) { + if (le->previous != NULL) + le->previous->next = le->next; + if (le->next != NULL) + le->next->previous = le->previous; + if (cpio->links_head == le) + cpio->links_head = le->next; + free(le); + } + + return; + } + } + + le = malloc(sizeof(struct links_entry)); + if (cpio->links_head != NULL) + cpio->links_head->previous = le; + le->next = cpio->links_head; + le->previous = NULL; + cpio->links_head = le; + le->dev = st->st_dev; + le->ino = st->st_ino; + le->links = st->st_nlink - 1; + le->name = strdup(archive_entry_pathname(entry)); +} |