1From dd96882877721703e19272fe25034560b794061b Mon Sep 17 00:00:00 2001 2From: Sergey Poznyakoff <gray@gnu.org> 3Date: Sat, 7 Aug 2021 12:52:21 +0300 4Subject: Rewrite dynamic string support. 5 6* src/dstring.c (ds_init): Take a single argument. 7(ds_free): New function. 8(ds_resize): Take a single argument. Use x2nrealloc to expand 9the storage. 10(ds_reset,ds_append,ds_concat,ds_endswith): New function. 11(ds_fgetstr): Rewrite. In particular, this fixes integer overflow. 12* src/dstring.h (dynamic_string): Keep both the allocated length 13(ds_size) and index of the next free byte in the string (ds_idx). 14(ds_init,ds_resize): Change signature. 15(ds_len): New macro. 16(ds_free,ds_reset,ds_append,ds_concat,ds_endswith): New protos. 17* src/copyin.c: Use new ds_ functions. 18* src/copyout.c: Likewise. 19* src/copypass.c: Likewise. 20* src/util.c: Likewise. 21 22[Retrieved from: 23https://git.savannah.gnu.org/cgit/cpio.git/commit/?id=dd96882877721703e19272fe25034560b794061b] 24Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com> 25--- 26 src/copyin.c | 40 +++++++++++++------------- 27 src/copyout.c | 16 ++++------- 28 src/copypass.c | 34 +++++++++++------------ 29 src/dstring.c | 88 ++++++++++++++++++++++++++++++++++++++++++---------------- 30 src/dstring.h | 31 ++++++++++----------- 31 src/util.c | 6 ++-- 32 6 files changed, 123 insertions(+), 92 deletions(-) 33 34diff --git a/src/copyin.c b/src/copyin.c 35index a096048..4fb14af 100644 36--- a/src/copyin.c 37+++ b/src/copyin.c 38@@ -55,11 +55,12 @@ query_rename(struct cpio_file_stat* file_hdr, FILE *tty_in, FILE *tty_out, 39 char *str_res; /* Result for string function. */ 40 static dynamic_string new_name; /* New file name for rename option. */ 41 static int initialized_new_name = false; 42+ 43 if (!initialized_new_name) 44- { 45- ds_init (&new_name, 128); 46- initialized_new_name = true; 47- } 48+ { 49+ ds_init (&new_name); 50+ initialized_new_name = true; 51+ } 52 53 if (rename_flag) 54 { 55@@ -780,37 +781,36 @@ long_format (struct cpio_file_stat *file_hdr, char const *link_name) 56 already in `save_patterns' (from the command line) are preserved. */ 57 58 static void 59-read_pattern_file () 60+read_pattern_file (void) 61 { 62- int max_new_patterns; 63- char **new_save_patterns; 64- int new_num_patterns; 65+ char **new_save_patterns = NULL; 66+ size_t max_new_patterns; 67+ size_t new_num_patterns; 68 int i; 69- dynamic_string pattern_name; 70+ dynamic_string pattern_name = DYNAMIC_STRING_INITIALIZER; 71 FILE *pattern_fp; 72 73 if (num_patterns < 0) 74 num_patterns = 0; 75- max_new_patterns = 1 + num_patterns; 76- new_save_patterns = (char **) xmalloc (max_new_patterns * sizeof (char *)); 77 new_num_patterns = num_patterns; 78- ds_init (&pattern_name, 128); 79+ max_new_patterns = num_patterns; 80+ new_save_patterns = xcalloc (max_new_patterns, sizeof (new_save_patterns[0])); 81 82 pattern_fp = fopen (pattern_file_name, "r"); 83 if (pattern_fp == NULL) 84 open_fatal (pattern_file_name); 85 while (ds_fgetstr (pattern_fp, &pattern_name, '\n') != NULL) 86 { 87- if (new_num_patterns >= max_new_patterns) 88- { 89- max_new_patterns += 1; 90- new_save_patterns = (char **) 91- xrealloc ((char *) new_save_patterns, 92- max_new_patterns * sizeof (char *)); 93- } 94+ if (new_num_patterns == max_new_patterns) 95+ new_save_patterns = x2nrealloc (new_save_patterns, 96+ &max_new_patterns, 97+ sizeof (new_save_patterns[0])); 98 new_save_patterns[new_num_patterns] = xstrdup (pattern_name.ds_string); 99 ++new_num_patterns; 100 } 101+ 102+ ds_free (&pattern_name); 103+ 104 if (ferror (pattern_fp) || fclose (pattern_fp) == EOF) 105 close_error (pattern_file_name); 106 107@@ -1210,7 +1210,7 @@ swab_array (char *ptr, int count) 108 in the file system. */ 109 110 void 111-process_copy_in () 112+process_copy_in (void) 113 { 114 FILE *tty_in = NULL; /* Interactive file for rename option. */ 115 FILE *tty_out = NULL; /* Interactive file for rename option. */ 116diff --git a/src/copyout.c b/src/copyout.c 117index 5ca587f..ca6798c 100644 118--- a/src/copyout.c 119+++ b/src/copyout.c 120@@ -594,9 +594,10 @@ assign_string (char **pvar, char *value) 121 The format of the header depends on the compatibility (-c) flag. */ 122 123 void 124-process_copy_out () 125+process_copy_out (void) 126 { 127- dynamic_string input_name; /* Name of file read from stdin. */ 128+ dynamic_string input_name = DYNAMIC_STRING_INITIALIZER; 129+ /* Name of file read from stdin. */ 130 struct stat file_stat; /* Stat record for file. */ 131 struct cpio_file_stat file_hdr = CPIO_FILE_STAT_INITIALIZER; 132 /* Output header information. */ 133@@ -605,7 +606,6 @@ process_copy_out () 134 char *orig_file_name = NULL; 135 136 /* Initialize the copy out. */ 137- ds_init (&input_name, 128); 138 file_hdr.c_magic = 070707; 139 140 /* Check whether the output file might be a tape. */ 141@@ -657,14 +657,9 @@ process_copy_out () 142 { 143 if (file_hdr.c_mode & CP_IFDIR) 144 { 145- int len = strlen (input_name.ds_string); 146 /* Make sure the name ends with a slash */ 147- if (input_name.ds_string[len-1] != '/') 148- { 149- ds_resize (&input_name, len + 2); 150- input_name.ds_string[len] = '/'; 151- input_name.ds_string[len+1] = 0; 152- } 153+ if (!ds_endswith (&input_name, '/')) 154+ ds_append (&input_name, '/'); 155 } 156 } 157 158@@ -875,6 +870,7 @@ process_copy_out () 159 (unsigned long) blocks), (unsigned long) blocks); 160 } 161 cpio_file_stat_free (&file_hdr); 162+ ds_free (&input_name); 163 } 164 165 166diff --git a/src/copypass.c b/src/copypass.c 167index 5d5e939..23ee687 100644 168--- a/src/copypass.c 169+++ b/src/copypass.c 170@@ -48,10 +48,12 @@ set_copypass_perms (int fd, const char *name, struct stat *st) 171 If `link_flag', link instead of copying. */ 172 173 void 174-process_copy_pass () 175+process_copy_pass (void) 176 { 177- dynamic_string input_name; /* Name of file from stdin. */ 178- dynamic_string output_name; /* Name of new file. */ 179+ dynamic_string input_name = DYNAMIC_STRING_INITIALIZER; 180+ /* Name of file from stdin. */ 181+ dynamic_string output_name = DYNAMIC_STRING_INITIALIZER; 182+ /* Name of new file. */ 183 size_t dirname_len; /* Length of `directory_name'. */ 184 int res; /* Result of functions. */ 185 char *slash; /* For moving past slashes in input name. */ 186@@ -65,25 +67,18 @@ process_copy_pass () 187 created files */ 188 189 /* Initialize the copy pass. */ 190- ds_init (&input_name, 128); 191 192 dirname_len = strlen (directory_name); 193 if (change_directory_option && !ISSLASH (directory_name[0])) 194 { 195 char *pwd = xgetcwd (); 196- 197- dirname_len += strlen (pwd) + 1; 198- ds_init (&output_name, dirname_len + 2); 199- strcpy (output_name.ds_string, pwd); 200- strcat (output_name.ds_string, "/"); 201- strcat (output_name.ds_string, directory_name); 202+ 203+ ds_concat (&output_name, pwd); 204+ ds_append (&output_name, '/'); 205 } 206- else 207- { 208- ds_init (&output_name, dirname_len + 2); 209- strcpy (output_name.ds_string, directory_name); 210- } 211- output_name.ds_string[dirname_len] = '/'; 212+ ds_concat (&output_name, directory_name); 213+ ds_append (&output_name, '/'); 214+ dirname_len = ds_len (&output_name); 215 output_is_seekable = true; 216 217 change_dir (); 218@@ -116,8 +111,8 @@ process_copy_pass () 219 /* Make the name of the new file. */ 220 for (slash = input_name.ds_string; *slash == '/'; ++slash) 221 ; 222- ds_resize (&output_name, dirname_len + strlen (slash) + 2); 223- strcpy (output_name.ds_string + dirname_len + 1, slash); 224+ ds_reset (&output_name, dirname_len); 225+ ds_concat (&output_name, slash); 226 227 existing_dir = false; 228 if (lstat (output_name.ds_string, &out_file_stat) == 0) 229@@ -333,6 +328,9 @@ process_copy_pass () 230 (unsigned long) blocks), 231 (unsigned long) blocks); 232 } 233+ 234+ ds_free (&input_name); 235+ ds_free (&output_name); 236 } 237 238 /* Try and create a hard link from FILE_NAME to another file 239diff --git a/src/dstring.c b/src/dstring.c 240index b261d5a..692d3e7 100644 241--- a/src/dstring.c 242+++ b/src/dstring.c 243@@ -20,8 +20,8 @@ 244 #if defined(HAVE_CONFIG_H) 245 # include <config.h> 246 #endif 247- 248 #include <stdio.h> 249+#include <stdlib.h> 250 #if defined(HAVE_STRING_H) || defined(STDC_HEADERS) 251 #include <string.h> 252 #else 253@@ -33,24 +33,41 @@ 254 /* Initialiaze dynamic string STRING with space for SIZE characters. */ 255 256 void 257-ds_init (dynamic_string *string, int size) 258+ds_init (dynamic_string *string) 259+{ 260+ memset (string, 0, sizeof *string); 261+} 262+ 263+/* Free the dynamic string storage. */ 264+ 265+void 266+ds_free (dynamic_string *string) 267 { 268- string->ds_length = size; 269- string->ds_string = (char *) xmalloc (size); 270+ free (string->ds_string); 271 } 272 273-/* Expand dynamic string STRING, if necessary, to hold SIZE characters. */ 274+/* Expand dynamic string STRING, if necessary. */ 275 276 void 277-ds_resize (dynamic_string *string, int size) 278+ds_resize (dynamic_string *string) 279 { 280- if (size > string->ds_length) 281+ if (string->ds_idx == string->ds_size) 282 { 283- string->ds_length = size; 284- string->ds_string = (char *) xrealloc ((char *) string->ds_string, size); 285+ string->ds_string = x2nrealloc (string->ds_string, &string->ds_size, 286+ 1); 287 } 288 } 289 290+/* Reset the index of the dynamic string S to LEN. */ 291+ 292+void 293+ds_reset (dynamic_string *s, size_t len) 294+{ 295+ while (len > s->ds_size) 296+ ds_resize (s); 297+ s->ds_idx = len; 298+} 299+ 300 /* Dynamic string S gets a string terminated by the EOS character 301 (which is removed) from file F. S will increase 302 in size during the function if the string from F is longer than 303@@ -61,34 +78,50 @@ ds_resize (dynamic_string *string, int size) 304 char * 305 ds_fgetstr (FILE *f, dynamic_string *s, char eos) 306 { 307- int insize; /* Amount needed for line. */ 308- int strsize; /* Amount allocated for S. */ 309 int next_ch; 310 311 /* Initialize. */ 312- insize = 0; 313- strsize = s->ds_length; 314+ s->ds_idx = 0; 315 316 /* Read the input string. */ 317- next_ch = getc (f); 318- while (next_ch != eos && next_ch != EOF) 319+ while ((next_ch = getc (f)) != eos && next_ch != EOF) 320 { 321- if (insize >= strsize - 1) 322- { 323- ds_resize (s, strsize * 2 + 2); 324- strsize = s->ds_length; 325- } 326- s->ds_string[insize++] = next_ch; 327- next_ch = getc (f); 328+ ds_resize (s); 329+ s->ds_string[s->ds_idx++] = next_ch; 330 } 331- s->ds_string[insize++] = '\0'; 332+ ds_resize (s); 333+ s->ds_string[s->ds_idx] = '\0'; 334 335- if (insize == 1 && next_ch == EOF) 336+ if (s->ds_idx == 0 && next_ch == EOF) 337 return NULL; 338 else 339 return s->ds_string; 340 } 341 342+void 343+ds_append (dynamic_string *s, int c) 344+{ 345+ ds_resize (s); 346+ s->ds_string[s->ds_idx] = c; 347+ if (c) 348+ { 349+ s->ds_idx++; 350+ ds_resize (s); 351+ s->ds_string[s->ds_idx] = 0; 352+ } 353+} 354+ 355+void 356+ds_concat (dynamic_string *s, char const *str) 357+{ 358+ size_t len = strlen (str); 359+ while (len + 1 > s->ds_size) 360+ ds_resize (s); 361+ memcpy (s->ds_string + s->ds_idx, str, len); 362+ s->ds_idx += len; 363+ s->ds_string[s->ds_idx] = 0; 364+} 365+ 366 char * 367 ds_fgets (FILE *f, dynamic_string *s) 368 { 369@@ -100,3 +133,10 @@ ds_fgetname (FILE *f, dynamic_string *s) 370 { 371 return ds_fgetstr (f, s, '\0'); 372 } 373+ 374+/* Return true if the dynamic string S ends with character C. */ 375+int 376+ds_endswith (dynamic_string *s, int c) 377+{ 378+ return (s->ds_idx > 0 && s->ds_string[s->ds_idx - 1] == c); 379+} 380diff --git a/src/dstring.h b/src/dstring.h 381index 5d24181..ca7a5f1 100644 382--- a/src/dstring.h 383+++ b/src/dstring.h 384@@ -17,10 +17,6 @@ 385 Software Foundation, Inc., 51 Franklin Street, Fifth Floor, 386 Boston, MA 02110-1301 USA. */ 387 388-#ifndef NULL 389-#define NULL 0 390-#endif 391- 392 /* A dynamic string consists of record that records the size of an 393 allocated string and the pointer to that string. The actual string 394 is a normal zero byte terminated string that can be used with the 395@@ -30,22 +26,25 @@ 396 397 typedef struct 398 { 399- int ds_length; /* Actual amount of storage allocated. */ 400- char *ds_string; /* String. */ 401+ size_t ds_size; /* Actual amount of storage allocated. */ 402+ size_t ds_idx; /* Index of the next free byte in the string. */ 403+ char *ds_string; /* String storage. */ 404 } dynamic_string; 405 406+#define DYNAMIC_STRING_INITIALIZER { 0, 0, NULL } 407 408-/* Macros that look similar to the original string functions. 409- WARNING: These macros work only on pointers to dynamic string records. 410- If used with a real record, an "&" must be used to get the pointer. */ 411-#define ds_strlen(s) strlen ((s)->ds_string) 412-#define ds_strcmp(s1, s2) strcmp ((s1)->ds_string, (s2)->ds_string) 413-#define ds_strncmp(s1, s2, n) strncmp ((s1)->ds_string, (s2)->ds_string, n) 414-#define ds_index(s, c) index ((s)->ds_string, c) 415-#define ds_rindex(s, c) rindex ((s)->ds_string, c) 416+void ds_init (dynamic_string *string); 417+void ds_free (dynamic_string *string); 418+void ds_reset (dynamic_string *s, size_t len); 419 420-void ds_init (dynamic_string *string, int size); 421-void ds_resize (dynamic_string *string, int size); 422+/* All functions below guarantee that s->ds_string[s->ds_idx] == '\0' */ 423 char *ds_fgetname (FILE *f, dynamic_string *s); 424 char *ds_fgets (FILE *f, dynamic_string *s); 425 char *ds_fgetstr (FILE *f, dynamic_string *s, char eos); 426+void ds_append (dynamic_string *s, int c); 427+void ds_concat (dynamic_string *s, char const *str); 428+ 429+#define ds_len(s) ((s)->ds_idx) 430+ 431+int ds_endswith (dynamic_string *s, int c); 432+ 433diff --git a/src/util.c b/src/util.c 434index 996d4fa..ff2746d 100644 435--- a/src/util.c 436+++ b/src/util.c 437@@ -846,11 +846,9 @@ get_next_reel (int tape_des) 438 FILE *tty_out; /* File for interacting with user. */ 439 int old_tape_des; 440 char *next_archive_name; 441- dynamic_string new_name; 442+ dynamic_string new_name = DYNAMIC_STRING_INITIALIZER; 443 char *str_res; 444 445- ds_init (&new_name, 128); 446- 447 /* Open files for interactive communication. */ 448 tty_in = fopen (TTY_NAME, "r"); 449 if (tty_in == NULL) 450@@ -925,7 +923,7 @@ get_next_reel (int tape_des) 451 error (PAXEXIT_FAILURE, 0, _("internal error: tape descriptor changed from %d to %d"), 452 old_tape_des, tape_des); 453 454- free (new_name.ds_string); 455+ ds_free (&new_name); 456 fclose (tty_in); 457 fclose (tty_out); 458 } 459-- 460cgit v1.2.1 461 462