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authorSergey Poznyakoff <gray@gnu.org>2021-08-07 12:52:21 +0300
committerSergey Poznyakoff <gray@gnu.org>2021-08-07 12:52:21 +0300
commitdd96882877721703e19272fe25034560b794061b (patch)
tree2d81f2521f55cf3d82e7305d1475be9c8c1e0812
parent269d2040a62e45a35d7f5eef3e868813d44213c0 (diff)
downloadcpio-dd96882877721703e19272fe25034560b794061b.tar.gz
cpio-dd96882877721703e19272fe25034560b794061b.tar.bz2
Rewrite dynamic string support.
* src/dstring.c (ds_init): Take a single argument. (ds_free): New function. (ds_resize): Take a single argument. Use x2nrealloc to expand the storage. (ds_reset,ds_append,ds_concat,ds_endswith): New function. (ds_fgetstr): Rewrite. In particular, this fixes integer overflow. * src/dstring.h (dynamic_string): Keep both the allocated length (ds_size) and index of the next free byte in the string (ds_idx). (ds_init,ds_resize): Change signature. (ds_len): New macro. (ds_free,ds_reset,ds_append,ds_concat,ds_endswith): New protos. * src/copyin.c: Use new ds_ functions. * src/copyout.c: Likewise. * src/copypass.c: Likewise. * src/util.c: Likewise.
-rw-r--r--src/copyin.c40
-rw-r--r--src/copyout.c16
-rw-r--r--src/copypass.c34
-rw-r--r--src/dstring.c88
-rw-r--r--src/dstring.h31
-rw-r--r--src/util.c6
6 files changed, 123 insertions, 92 deletions
diff --git a/src/copyin.c b/src/copyin.c
index a096048..4fb14af 100644
--- a/src/copyin.c
+++ b/src/copyin.c
@@ -55,11 +55,12 @@ query_rename(struct cpio_file_stat* file_hdr, FILE *tty_in, FILE *tty_out,
char *str_res; /* Result for string function. */
static dynamic_string new_name; /* New file name for rename option. */
static int initialized_new_name = false;
+
if (!initialized_new_name)
- {
- ds_init (&new_name, 128);
- initialized_new_name = true;
- }
+ {
+ ds_init (&new_name);
+ initialized_new_name = true;
+ }
if (rename_flag)
{
@@ -780,37 +781,36 @@ long_format (struct cpio_file_stat *file_hdr, char const *link_name)
already in `save_patterns' (from the command line) are preserved. */
static void
-read_pattern_file ()
+read_pattern_file (void)
{
- int max_new_patterns;
- char **new_save_patterns;
- int new_num_patterns;
+ char **new_save_patterns = NULL;
+ size_t max_new_patterns;
+ size_t new_num_patterns;
int i;
- dynamic_string pattern_name;
+ dynamic_string pattern_name = DYNAMIC_STRING_INITIALIZER;
FILE *pattern_fp;
if (num_patterns < 0)
num_patterns = 0;
- max_new_patterns = 1 + num_patterns;
- new_save_patterns = (char **) xmalloc (max_new_patterns * sizeof (char *));
new_num_patterns = num_patterns;
- ds_init (&pattern_name, 128);
+ max_new_patterns = num_patterns;
+ new_save_patterns = xcalloc (max_new_patterns, sizeof (new_save_patterns[0]));
pattern_fp = fopen (pattern_file_name, "r");
if (pattern_fp == NULL)
open_fatal (pattern_file_name);
while (ds_fgetstr (pattern_fp, &pattern_name, '\n') != NULL)
{
- if (new_num_patterns >= max_new_patterns)
- {
- max_new_patterns += 1;
- new_save_patterns = (char **)
- xrealloc ((char *) new_save_patterns,
- max_new_patterns * sizeof (char *));
- }
+ if (new_num_patterns == max_new_patterns)
+ new_save_patterns = x2nrealloc (new_save_patterns,
+ &max_new_patterns,
+ sizeof (new_save_patterns[0]));
new_save_patterns[new_num_patterns] = xstrdup (pattern_name.ds_string);
++new_num_patterns;
}
+
+ ds_free (&pattern_name);
+
if (ferror (pattern_fp) || fclose (pattern_fp) == EOF)
close_error (pattern_file_name);
@@ -1210,7 +1210,7 @@ swab_array (char *ptr, int count)
in the file system. */
void
-process_copy_in ()
+process_copy_in (void)
{
FILE *tty_in = NULL; /* Interactive file for rename option. */
FILE *tty_out = NULL; /* Interactive file for rename option. */
diff --git a/src/copyout.c b/src/copyout.c
index 5ca587f..ca6798c 100644
--- a/src/copyout.c
+++ b/src/copyout.c
@@ -594,9 +594,10 @@ assign_string (char **pvar, char *value)
The format of the header depends on the compatibility (-c) flag. */
void
-process_copy_out ()
+process_copy_out (void)
{
- dynamic_string input_name; /* Name of file read from stdin. */
+ dynamic_string input_name = DYNAMIC_STRING_INITIALIZER;
+ /* Name of file read from stdin. */
struct stat file_stat; /* Stat record for file. */
struct cpio_file_stat file_hdr = CPIO_FILE_STAT_INITIALIZER;
/* Output header information. */
@@ -605,7 +606,6 @@ process_copy_out ()
char *orig_file_name = NULL;
/* Initialize the copy out. */
- ds_init (&input_name, 128);
file_hdr.c_magic = 070707;
/* Check whether the output file might be a tape. */
@@ -657,14 +657,9 @@ process_copy_out ()
{
if (file_hdr.c_mode & CP_IFDIR)
{
- int len = strlen (input_name.ds_string);
/* Make sure the name ends with a slash */
- if (input_name.ds_string[len-1] != '/')
- {
- ds_resize (&input_name, len + 2);
- input_name.ds_string[len] = '/';
- input_name.ds_string[len+1] = 0;
- }
+ if (!ds_endswith (&input_name, '/'))
+ ds_append (&input_name, '/');
}
}
@@ -875,6 +870,7 @@ process_copy_out ()
(unsigned long) blocks), (unsigned long) blocks);
}
cpio_file_stat_free (&file_hdr);
+ ds_free (&input_name);
}
diff --git a/src/copypass.c b/src/copypass.c
index 5d5e939..23ee687 100644
--- a/src/copypass.c
+++ b/src/copypass.c
@@ -48,10 +48,12 @@ set_copypass_perms (int fd, const char *name, struct stat *st)
If `link_flag', link instead of copying. */
void
-process_copy_pass ()
+process_copy_pass (void)
{
- dynamic_string input_name; /* Name of file from stdin. */
- dynamic_string output_name; /* Name of new file. */
+ dynamic_string input_name = DYNAMIC_STRING_INITIALIZER;
+ /* Name of file from stdin. */
+ dynamic_string output_name = DYNAMIC_STRING_INITIALIZER;
+ /* Name of new file. */
size_t dirname_len; /* Length of `directory_name'. */
int res; /* Result of functions. */
char *slash; /* For moving past slashes in input name. */
@@ -65,25 +67,18 @@ process_copy_pass ()
created files */
/* Initialize the copy pass. */
- ds_init (&input_name, 128);
dirname_len = strlen (directory_name);
if (change_directory_option && !ISSLASH (directory_name[0]))
{
char *pwd = xgetcwd ();
-
- dirname_len += strlen (pwd) + 1;
- ds_init (&output_name, dirname_len + 2);
- strcpy (output_name.ds_string, pwd);
- strcat (output_name.ds_string, "/");
- strcat (output_name.ds_string, directory_name);
+
+ ds_concat (&output_name, pwd);
+ ds_append (&output_name, '/');
}
- else
- {
- ds_init (&output_name, dirname_len + 2);
- strcpy (output_name.ds_string, directory_name);
- }
- output_name.ds_string[dirname_len] = '/';
+ ds_concat (&output_name, directory_name);
+ ds_append (&output_name, '/');
+ dirname_len = ds_len (&output_name);
output_is_seekable = true;
change_dir ();
@@ -116,8 +111,8 @@ process_copy_pass ()
/* Make the name of the new file. */
for (slash = input_name.ds_string; *slash == '/'; ++slash)
;
- ds_resize (&output_name, dirname_len + strlen (slash) + 2);
- strcpy (output_name.ds_string + dirname_len + 1, slash);
+ ds_reset (&output_name, dirname_len);
+ ds_concat (&output_name, slash);
existing_dir = false;
if (lstat (output_name.ds_string, &out_file_stat) == 0)
@@ -333,6 +328,9 @@ process_copy_pass ()
(unsigned long) blocks),
(unsigned long) blocks);
}
+
+ ds_free (&input_name);
+ ds_free (&output_name);
}
/* Try and create a hard link from FILE_NAME to another file
diff --git a/src/dstring.c b/src/dstring.c
index b261d5a..692d3e7 100644
--- a/src/dstring.c
+++ b/src/dstring.c
@@ -20,8 +20,8 @@
#if defined(HAVE_CONFIG_H)
# include <config.h>
#endif
-
#include <stdio.h>
+#include <stdlib.h>
#if defined(HAVE_STRING_H) || defined(STDC_HEADERS)
#include <string.h>
#else
@@ -33,24 +33,41 @@
/* Initialiaze dynamic string STRING with space for SIZE characters. */
void
-ds_init (dynamic_string *string, int size)
+ds_init (dynamic_string *string)
+{
+ memset (string, 0, sizeof *string);
+}
+
+/* Free the dynamic string storage. */
+
+void
+ds_free (dynamic_string *string)
{
- string->ds_length = size;
- string->ds_string = (char *) xmalloc (size);
+ free (string->ds_string);
}
-/* Expand dynamic string STRING, if necessary, to hold SIZE characters. */
+/* Expand dynamic string STRING, if necessary. */
void
-ds_resize (dynamic_string *string, int size)
+ds_resize (dynamic_string *string)
{
- if (size > string->ds_length)
+ if (string->ds_idx == string->ds_size)
{
- string->ds_length = size;
- string->ds_string = (char *) xrealloc ((char *) string->ds_string, size);
+ string->ds_string = x2nrealloc (string->ds_string, &string->ds_size,
+ 1);
}
}
+/* Reset the index of the dynamic string S to LEN. */
+
+void
+ds_reset (dynamic_string *s, size_t len)
+{
+ while (len > s->ds_size)
+ ds_resize (s);
+ s->ds_idx = len;
+}
+
/* Dynamic string S gets a string terminated by the EOS character
(which is removed) from file F. S will increase
in size during the function if the string from F is longer than
@@ -61,34 +78,50 @@ ds_resize (dynamic_string *string, int size)
char *
ds_fgetstr (FILE *f, dynamic_string *s, char eos)
{
- int insize; /* Amount needed for line. */
- int strsize; /* Amount allocated for S. */
int next_ch;
/* Initialize. */
- insize = 0;
- strsize = s->ds_length;
+ s->ds_idx = 0;
/* Read the input string. */
- next_ch = getc (f);
- while (next_ch != eos && next_ch != EOF)
+ while ((next_ch = getc (f)) != eos && next_ch != EOF)
{
- if (insize >= strsize - 1)
- {
- ds_resize (s, strsize * 2 + 2);
- strsize = s->ds_length;
- }
- s->ds_string[insize++] = next_ch;
- next_ch = getc (f);
+ ds_resize (s);
+ s->ds_string[s->ds_idx++] = next_ch;
}
- s->ds_string[insize++] = '\0';
+ ds_resize (s);
+ s->ds_string[s->ds_idx] = '\0';
- if (insize == 1 && next_ch == EOF)
+ if (s->ds_idx == 0 && next_ch == EOF)
return NULL;
else
return s->ds_string;
}
+void
+ds_append (dynamic_string *s, int c)
+{
+ ds_resize (s);
+ s->ds_string[s->ds_idx] = c;
+ if (c)
+ {
+ s->ds_idx++;
+ ds_resize (s);
+ s->ds_string[s->ds_idx] = 0;
+ }
+}
+
+void
+ds_concat (dynamic_string *s, char const *str)
+{
+ size_t len = strlen (str);
+ while (len + 1 > s->ds_size)
+ ds_resize (s);
+ memcpy (s->ds_string + s->ds_idx, str, len);
+ s->ds_idx += len;
+ s->ds_string[s->ds_idx] = 0;
+}
+
char *
ds_fgets (FILE *f, dynamic_string *s)
{
@@ -100,3 +133,10 @@ ds_fgetname (FILE *f, dynamic_string *s)
{
return ds_fgetstr (f, s, '\0');
}
+
+/* Return true if the dynamic string S ends with character C. */
+int
+ds_endswith (dynamic_string *s, int c)
+{
+ return (s->ds_idx > 0 && s->ds_string[s->ds_idx - 1] == c);
+}
diff --git a/src/dstring.h b/src/dstring.h
index 5d24181..ca7a5f1 100644
--- a/src/dstring.h
+++ b/src/dstring.h
@@ -17,10 +17,6 @@
Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
Boston, MA 02110-1301 USA. */
-#ifndef NULL
-#define NULL 0
-#endif
-
/* A dynamic string consists of record that records the size of an
allocated string and the pointer to that string. The actual string
is a normal zero byte terminated string that can be used with the
@@ -30,22 +26,25 @@
typedef struct
{
- int ds_length; /* Actual amount of storage allocated. */
- char *ds_string; /* String. */
+ size_t ds_size; /* Actual amount of storage allocated. */
+ size_t ds_idx; /* Index of the next free byte in the string. */
+ char *ds_string; /* String storage. */
} dynamic_string;
+#define DYNAMIC_STRING_INITIALIZER { 0, 0, NULL }
-/* Macros that look similar to the original string functions.
- WARNING: These macros work only on pointers to dynamic string records.
- If used with a real record, an "&" must be used to get the pointer. */
-#define ds_strlen(s) strlen ((s)->ds_string)
-#define ds_strcmp(s1, s2) strcmp ((s1)->ds_string, (s2)->ds_string)
-#define ds_strncmp(s1, s2, n) strncmp ((s1)->ds_string, (s2)->ds_string, n)
-#define ds_index(s, c) index ((s)->ds_string, c)
-#define ds_rindex(s, c) rindex ((s)->ds_string, c)
+void ds_init (dynamic_string *string);
+void ds_free (dynamic_string *string);
+void ds_reset (dynamic_string *s, size_t len);
-void ds_init (dynamic_string *string, int size);
-void ds_resize (dynamic_string *string, int size);
+/* All functions below guarantee that s->ds_string[s->ds_idx] == '\0' */
char *ds_fgetname (FILE *f, dynamic_string *s);
char *ds_fgets (FILE *f, dynamic_string *s);
char *ds_fgetstr (FILE *f, dynamic_string *s, char eos);
+void ds_append (dynamic_string *s, int c);
+void ds_concat (dynamic_string *s, char const *str);
+
+#define ds_len(s) ((s)->ds_idx)
+
+int ds_endswith (dynamic_string *s, int c);
+
diff --git a/src/util.c b/src/util.c
index 996d4fa..ff2746d 100644
--- a/src/util.c
+++ b/src/util.c
@@ -846,11 +846,9 @@ get_next_reel (int tape_des)
FILE *tty_out; /* File for interacting with user. */
int old_tape_des;
char *next_archive_name;
- dynamic_string new_name;
+ dynamic_string new_name = DYNAMIC_STRING_INITIALIZER;
char *str_res;
- ds_init (&new_name, 128);
-
/* Open files for interactive communication. */
tty_in = fopen (TTY_NAME, "r");
if (tty_in == NULL)
@@ -925,7 +923,7 @@ get_next_reel (int tape_des)
error (PAXEXIT_FAILURE, 0, _("internal error: tape descriptor changed from %d to %d"),
old_tape_des, tape_des);
- free (new_name.ds_string);
+ ds_free (&new_name);
fclose (tty_in);
fclose (tty_out);
}

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