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Refactor the mtree code a bit to make the layering clearer: Each

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"file" is described by multiple "lines" each possibly containing
multiple "keywords."  Incorporate some additions from Joerg Sonnenberger
to handle linked files and correctly deal with backing files on disk.
This commit is contained in:
Tim Kientzle 2008-03-15 07:10:24 +00:00
parent 6302d5936a
commit 3010219939
1 changed files with 184 additions and 118 deletions
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302
lib/libarchive/archive_read_support_format_mtree.c
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@ -76,12 +76,18 @@ struct mtree {
struct mtree_entry *this_entry;
struct archive_string current_dir;
struct archive_string contents_name;
off_t cur_size, cur_offset;
};
static int cleanup(struct archive_read *);
static int mtree_bid(struct archive_read *);
static int parse_file(struct archive_read *, struct archive_entry *,
struct mtree *, struct mtree_entry *);
static void parse_escapes(char *, struct mtree_entry *);
static int parse_setting(struct archive_read *, struct mtree *,
static int parse_line(struct archive_read *, struct archive_entry *,
struct mtree *, struct mtree_entry *);
static int parse_keyword(struct archive_read *, struct mtree *,
struct archive_entry *, char *, char *);
static int read_data(struct archive_read *a,
const void **buff, size_t *size, off_t *offset);
@ -252,14 +258,16 @@ read_mtree(struct archive_read *a, struct mtree *mtree)
}
}
/*
* Read in the entire mtree file into memory on the first request.
* Then use the next unused file to satisfy each header request.
*/
static int
read_header(struct archive_read *a, struct archive_entry *entry)
{
struct stat st;
struct mtree *mtree;
struct mtree_entry *mentry, *mentry2;
char *p, *q;
int r = ARCHIVE_OK, r1;
char *p;
int r;
mtree = (struct mtree *)(a->format->data);
@ -278,16 +286,10 @@ read_header(struct archive_read *a, struct archive_entry *entry)
a->archive.archive_format_name = mtree->archive_format_name;
for (;;) {
mentry = mtree->this_entry;
if (mentry == NULL) {
mtree->this_entry = NULL;
if (mtree->this_entry == NULL)
return (ARCHIVE_EOF);
}
mtree->this_entry = mentry->next;
if (mentry->used)
continue;
mentry->used = 1;
if (strcmp(mentry->name, "..") == 0) {
if (strcmp(mtree->this_entry->name, "..") == 0) {
mtree->this_entry->used = 1;
if (archive_strlen(&mtree->current_dir) > 0) {
/* Roll back current path. */
p = mtree->current_dir.s
@ -299,117 +301,165 @@ read_header(struct archive_read *a, struct archive_entry *entry)
mtree->current_dir.length
= p - mtree->current_dir.s + 1;
}
continue;
}
mtree->filetype = AE_IFREG;
/* Parse options. */
p = mentry->option_start;
while (p < mentry->option_end) {
q = p + strlen(p);
r1 = parse_setting(a, mtree, entry, p, q);
if (r1 != ARCHIVE_OK)
r = r1;
p = q + 1;
if (!mtree->this_entry->used) {
r = parse_file(a, entry, mtree, mtree->this_entry);
return (r);
}
if (mentry->full) {
archive_entry_copy_pathname(entry, mentry->name);
/*
* "Full" entries are allowed to have multiple
* lines and those lines aren't required to be
* adjacent. We don't support multiple lines
* for "relative" entries nor do we make any
* attempt to merge data from separate
* "relative" and "full" entries. (Merging
* "relative" and "full" entries would require
* dealing with pathname canonicalization,
* which is a very tricky subject.)
*/
mentry2 = mentry->next;
while (mentry2 != NULL) {
if (mentry2->full
&& !mentry2->used
&& strcmp(mentry->name, mentry2->name) == 0) {
/*
* Add those options as well;
* later lines override
* earlier ones.
*/
p = mentry2->option_start;
while (p < mentry2->option_end) {
q = p + strlen(p);
r1 = parse_setting(a, mtree, entry, p, q);
if (r1 != ARCHIVE_OK)
r = r1;
p = q + 1;
}
mentry2->used = 1;
}
mentry2 = mentry2->next;
}
} else {
/*
* Relative entries require us to construct
* the full path and possibly update the
* current directory.
*/
size_t n = archive_strlen(&mtree->current_dir);
if (n > 0)
archive_strcat(&mtree->current_dir, "/");
archive_strcat(&mtree->current_dir, mentry->name);
archive_entry_copy_pathname(entry, mtree->current_dir.s);
if (archive_entry_filetype(entry) != AE_IFDIR)
mtree->current_dir.length = n;
}
/*
* Try to open and stat the file to get the real size.
* It would be nice to avoid this here so that getting
* a listing of an mtree wouldn't require opening
* every referenced contents file. But then we
* wouldn't know the actual contents size, so I don't
* see a really viable way around this. (Also, we may
* want to someday pull other unspecified info from
* the contents file on disk.)
*/
if (archive_strlen(&mtree->contents_name) > 0) {
mtree->fd = open(mtree->contents_name.s,
O_RDONLY | O_BINARY);
if (mtree->fd < 0) {
archive_set_error(&a->archive, errno,
"Can't open content=\"%s\"",
mtree->contents_name.s);
r = ARCHIVE_WARN;
}
} else {
/* If the specified path opens, use it. */
mtree->fd = open(mtree->current_dir.s,
O_RDONLY | O_BINARY);
/* But don't fail if it's not there. */
}
/*
* If there is a contents file on disk, use that size;
* otherwise leave it as-is (it might have been set from
* the mtree size= keyword).
*/
if (mtree->fd >= 0) {
fstat(mtree->fd, &st);
archive_entry_set_size(entry, st.st_size);
}
return r;
mtree->this_entry = mtree->this_entry->next;
}
}
/*
* A single file can have multiple lines contribute specifications.
* Parse as many lines as necessary, then pull additional information
* from a backing file on disk as necessary.
*/
static int
parse_setting(struct archive_read *a, struct mtree *mtree, struct archive_entry *entry, char *key, char *end)
parse_file(struct archive_read *a, struct archive_entry *entry,
struct mtree *mtree, struct mtree_entry *mentry)
{
struct stat st;
struct mtree_entry *mp;
int r = ARCHIVE_OK, r1;
mentry->used = 1;
/* Initialize reasonable defaults. */
mtree->filetype = AE_IFREG;
archive_entry_set_size(entry, 0);
/* Parse options from this line. */
r = parse_line(a, entry, mtree, mentry);
if (mentry->full) {
archive_entry_copy_pathname(entry, mentry->name);
/*
* "Full" entries are allowed to have multiple lines
* and those lines aren't required to be adjacent. We
* don't support multiple lines for "relative" entries
* nor do we make any attempt to merge data from
* separate "relative" and "full" entries. (Merging
* "relative" and "full" entries would require dealing
* with pathname canonicalization, which is a very
* tricky subject.)
*/
for (mp = mentry->next; mp != NULL; mp = mp->next) {
if (mp->full && !mp->used
&& strcmp(mentry->name, mp->name) == 0) {
/* Later lines override earlier ones. */
mp->used = 1;
r1 = parse_line(a, entry, mtree, mp);
if (r1 < r)
r = r1;
}
}
} else {
/*
* Relative entries require us to construct
* the full path and possibly update the
* current directory.
*/
size_t n = archive_strlen(&mtree->current_dir);
if (n > 0)
archive_strcat(&mtree->current_dir, "/");
archive_strcat(&mtree->current_dir, mentry->name);
archive_entry_copy_pathname(entry, mtree->current_dir.s);
if (archive_entry_filetype(entry) != AE_IFDIR)
mtree->current_dir.length = n;
}
/*
* Try to open and stat the file to get the real size
* and other file info. It would be nice to avoid
* this here so that getting a listing of an mtree
* wouldn't require opening every referenced contents
* file. But then we wouldn't know the actual
* contents size, so I don't see a really viable way
* around this. (Also, we may want to someday pull
* other unspecified info from the contents file on
* disk.)
*/
mtree->fd = -1;
if (archive_strlen(&mtree->contents_name) > 0) {
mtree->fd = open(mtree->contents_name.s,
O_RDONLY | O_BINARY);
if (mtree->fd < 0) {
archive_set_error(&a->archive, errno,
"Can't open content=\"%s\"",
mtree->contents_name.s);
r = ARCHIVE_WARN;
}
} else if (archive_entry_filetype(entry) == AE_IFREG) {
mtree->fd = open(archive_entry_pathname(entry),
O_RDONLY | O_BINARY);
}
/*
* If there is a contents file on disk, use that size;
* otherwise leave it as-is (it might have been set from
* the mtree size= keyword).
*/
if (mtree->fd >= 0) {
if (fstat(mtree->fd, &st) != 0) {
archive_set_error(&a->archive, errno,
"could not stat %s",
archive_entry_pathname(entry));
r = ARCHIVE_WARN;
/* If we can't stat it, don't keep it open. */
close(mtree->fd);
mtree->fd = -1;
} else if ((st.st_mode & S_IFMT) != S_IFREG) {
archive_set_error(&a->archive, errno,
"%s is not a regular file",
archive_entry_pathname(entry));
r = ARCHIVE_WARN;
/* Don't hold a non-regular file open. */
close(mtree->fd);
mtree->fd = -1;
} else {
archive_entry_set_size(entry, st.st_size);
archive_entry_set_ino(entry, st.st_ino);
archive_entry_set_dev(entry, st.st_dev);
archive_entry_set_nlink(entry, st.st_nlink);
}
}
mtree->cur_size = archive_entry_size(entry);
mtree->offset = 0;
return r;
}
/*
* Each line contains a sequence of keywords.
*/
static int
parse_line(struct archive_read *a, struct archive_entry *entry,
struct mtree *mtree, struct mtree_entry *mp)
{
char *p, *q;
int r = ARCHIVE_OK, r1;
p = mp->option_start;
while (p < mp->option_end) {
q = p + strlen(p);
r1 = parse_keyword(a, mtree, entry, p, q);
if (r1 < r)
r = r1;
p = q + 1;
}
return (r);
}
/*
* Parse a single keyword and its value.
*/
static int
parse_keyword(struct archive_read *a, struct mtree *mtree,
struct archive_entry *entry, char *key, char *end)
{
char *val;
if (end == key)
return (ARCHIVE_OK);
if (*key == '\0')
@ -427,7 +477,8 @@ parse_setting(struct archive_read *a, struct mtree *mtree, struct archive_entry
switch (key[0]) {
case 'c':
if (strcmp(key, "content") == 0) {
if (strcmp(key, "content") == 0
|| strcmp(key, "contents") == 0) {
parse_escapes(val, NULL);
archive_strcpy(&mtree->contents_name, val);
break;
@ -441,6 +492,11 @@ parse_setting(struct archive_read *a, struct mtree *mtree, struct archive_entry
archive_entry_copy_gname(entry, val);
break;
}
case 'l':
if (strcmp(key, "link") == 0) {
archive_entry_set_link(entry, val);
break;
}
case 'm':
if (strcmp(key, "mode") == 0) {
if (val[0] == '0') {
@ -452,6 +508,11 @@ parse_setting(struct archive_read *a, struct mtree *mtree, struct archive_entry
"Symbolic mode \"%s\" unsupported", val);
break;
}
case 's':
if (strcmp(key, "size") == 0) {
archive_entry_set_size(entry, mtree_atol10(&val));
break;
}
case 't':
if (strcmp(key, "type") == 0) {
switch (val[0]) {
@ -517,6 +578,7 @@ parse_setting(struct archive_read *a, struct mtree *mtree, struct archive_entry
static int
read_data(struct archive_read *a, const void **buff, size_t *size, off_t *offset)
{
size_t bytes_to_read;
ssize_t bytes_read;
struct mtree *mtree;
@ -538,7 +600,11 @@ read_data(struct archive_read *a, const void **buff, size_t *size, off_t *offset
*buff = mtree->buff;
*offset = mtree->offset;
bytes_read = read(mtree->fd, mtree->buff, mtree->buffsize);
if (mtree->buffsize > mtree->cur_size - mtree->offset)
bytes_to_read = mtree->cur_size - mtree->offset;
else
bytes_to_read = mtree->buffsize;
bytes_read = read(mtree->fd, mtree->buff, bytes_to_read);
if (bytes_read < 0) {
archive_set_error(&a->archive, errno, "Can't read");
return (ARCHIVE_WARN);