From dd96882877721703e19272fe25034560b794061b Mon Sep 17 00:00:00 2001 From: Sergey Poznyakoff Date: Sat, 7 Aug 2021 12:52:21 +0300 Subject: 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. --- src/copyin.c | 40 +++++++++++++------------- src/copyout.c | 16 ++++------- src/copypass.c | 34 +++++++++++------------ src/dstring.c | 88 ++++++++++++++++++++++++++++++++++++++++++---------------- src/dstring.h | 31 ++++++++++----------- src/util.c | 6 ++-- 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 #endif - #include +#include #if defined(HAVE_STRING_H) || defined(STDC_HEADERS) #include #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); } -- cgit v1.2.1