1 /*************************************************
2 * Exim - an Internet mail transport agent *
3 *************************************************/
5 /* Copyright (c) University of Cambridge 1995 - 2018 */
6 /* Copyright (c) The Exim Maintainers 2020 - 2021 */
7 /* See the file NOTICE for conditions of use and distribution. */
9 /* Miscellaneous string-handling functions. Some are not required for
10 utilities and tests, and are cut out by the COMPILE_UTILITY macro. */
17 #ifndef COMPILE_UTILITY
18 /*************************************************
19 * Test for IP address *
20 *************************************************/
22 /* This used just to be a regular expression, but with IPv6 things are a bit
23 more complicated. If the address contains a colon, it is assumed to be a v6
24 address (assuming HAVE_IPV6 is set). If a mask is permitted and one is present,
25 and maskptr is not NULL, its offset is placed there.
29 maskptr NULL if no mask is permitted to follow
30 otherwise, points to an int where the offset of '/' is placed
31 if there is no / followed by trailing digits, *maskptr is set 0
33 Returns: 0 if the string is not a textual representation of an IP address
34 4 if it is an IPv4 address
35 6 if it is an IPv6 address
39 string_is_ip_address(const uschar *s, int *maskptr)
43 /* If an optional mask is permitted, check for it. If found, pass back the
48 const uschar *ss = s + Ustrlen(s);
50 if (s != ss && isdigit(*(--ss)))
52 while (ss > s && isdigit(ss[-1])) ss--;
53 if (ss > s && *(--ss) == '/') *maskptr = ss - s;
57 /* A colon anywhere in the string => IPv6 address */
59 if (Ustrchr(s, ':') != NULL)
61 BOOL had_double_colon = FALSE;
66 /* An IPv6 address must start with hex digit or double colon. A single
69 if (*s == ':' && *(++s) != ':') return 0;
71 /* Now read up to 8 components consisting of up to 4 hex digits each. There
72 may be one and only one appearance of double colon, which implies any number
73 of binary zero bits. The number of preceding components is held in count. */
75 for (int count = 0; count < 8; count++)
77 /* If the end of the string is reached before reading 8 components, the
78 address is valid provided a double colon has been read. This also applies
79 if we hit the / that introduces a mask or the % that introduces the
80 interface specifier (scope id) of a link-local address. */
82 if (*s == 0 || *s == '%' || *s == '/') return had_double_colon ? yield : 0;
84 /* If a component starts with an additional colon, we have hit a double
85 colon. This is permitted to appear once only, and counts as at least
86 one component. The final component may be of this form. */
90 if (had_double_colon) return 0;
91 had_double_colon = TRUE;
96 /* If the remainder of the string contains a dot but no colons, we
97 can expect a trailing IPv4 address. This is valid if either there has
98 been no double-colon and this is the 7th component (with the IPv4 address
99 being the 7th & 8th components), OR if there has been a double-colon
100 and fewer than 6 components. */
102 if (Ustrchr(s, ':') == NULL && Ustrchr(s, '.') != NULL)
104 if ((!had_double_colon && count != 6) ||
105 (had_double_colon && count > 6)) return 0;
111 /* Check for at least one and not more than 4 hex digits for this
114 if (!isxdigit(*s++)) return 0;
115 if (isxdigit(*s) && isxdigit(*(++s)) && isxdigit(*(++s))) s++;
117 /* If the component is terminated by colon and there is more to
118 follow, skip over the colon. If there is no more to follow the address is
121 if (*s == ':' && *(++s) == 0) return 0;
124 /* If about to handle a trailing IPv4 address, drop through. Otherwise
125 all is well if we are at the end of the string or at the mask or at a percent
126 sign, which introduces the interface specifier (scope id) of a link local
130 return (*s == 0 || *s == '%' ||
131 (*s == '/' && maskptr != NULL && *maskptr != 0))? yield : 0;
134 /* Test for IPv4 address, which may be the tail-end of an IPv6 address. */
136 for (int i = 0; i < 4; i++)
141 if (i != 0 && *s++ != '.') return 0;
142 n = strtol(CCS s, CSS &end, 10);
143 if (n > 255 || n < 0 || end <= s || end > s+3) return 0;
147 return !*s || (*s == '/' && maskptr && *maskptr != 0) ? yield : 0;
149 #endif /* COMPILE_UTILITY */
152 /*************************************************
153 * Format message size *
154 *************************************************/
156 /* Convert a message size in bytes to printing form, rounding
157 according to the magnitude of the number. A value of zero causes
158 a string of spaces to be returned.
161 size the message size in bytes
162 buffer where to put the answer
164 Returns: pointer to the buffer
165 a string of exactly 5 characters is normally returned
169 string_format_size(int size, uschar *buffer)
171 if (size == 0) Ustrcpy(buffer, US" ");
172 else if (size < 1024) sprintf(CS buffer, "%5d", size);
173 else if (size < 10*1024)
174 sprintf(CS buffer, "%4.1fK", (double)size / 1024.0);
175 else if (size < 1024*1024)
176 sprintf(CS buffer, "%4dK", (size + 512)/1024);
177 else if (size < 10*1024*1024)
178 sprintf(CS buffer, "%4.1fM", (double)size / (1024.0 * 1024.0));
180 sprintf(CS buffer, "%4dM", (size + 512 * 1024)/(1024*1024));
186 #ifndef COMPILE_UTILITY
187 /*************************************************
188 * Convert a number to base 62 format *
189 *************************************************/
191 /* Convert a long integer into an ASCII base 62 string. For Cygwin the value of
192 BASE_62 is actually 36. Always return exactly 6 characters plus zero, in a
195 Argument: a long integer
196 Returns: pointer to base 62 string
200 string_base62(unsigned long int value)
202 static uschar yield[7];
203 uschar *p = yield + sizeof(yield) - 1;
207 *(--p) = base62_chars[value % BASE_62];
212 #endif /* COMPILE_UTILITY */
216 /*************************************************
217 * Interpret escape sequence *
218 *************************************************/
220 /* This function is called from several places where escape sequences are to be
221 interpreted in strings.
224 pp points a pointer to the initiating "\" in the string;
225 the pointer gets updated to point to the final character
226 If the backslash is the last character in the string, it
228 Returns: the value of the character escape
232 string_interpret_escape(const uschar **pp)
234 #ifdef COMPILE_UTILITY
235 const uschar *hex_digits= CUS"0123456789abcdef";
238 const uschar *p = *pp;
240 if (ch == '\0') return **pp;
241 if (isdigit(ch) && ch != '8' && ch != '9')
244 if (isdigit(p[1]) && p[1] != '8' && p[1] != '9')
246 ch = ch * 8 + *(++p) - '0';
247 if (isdigit(p[1]) && p[1] != '8' && p[1] != '9')
248 ch = ch * 8 + *(++p) - '0';
253 case 'b': ch = '\b'; break;
254 case 'f': ch = '\f'; break;
255 case 'n': ch = '\n'; break;
256 case 'r': ch = '\r'; break;
257 case 't': ch = '\t'; break;
258 case 'v': ch = '\v'; break;
264 Ustrchr(hex_digits, tolower(*(++p))) - hex_digits;
265 if (isxdigit(p[1])) ch = ch * 16 +
266 Ustrchr(hex_digits, tolower(*(++p))) - hex_digits;
276 #ifndef COMPILE_UTILITY
277 /*************************************************
278 * Ensure string is printable *
279 *************************************************/
281 /* This function is called for critical strings. It checks for any
282 non-printing characters, and if any are found, it makes a new copy
283 of the string with suitable escape sequences. It is most often called by the
284 macro string_printing(), which sets flags to 0.
288 flags Bit 0: convert tabs. Bit 1: convert spaces.
290 Returns: string with non-printers encoded as printing sequences
294 string_printing2(const uschar *s, int flags)
296 int nonprintcount = 0;
305 || flags & SP_TAB && c == '\t'
306 || flags & SP_SPACE && c == ' '
311 if (nonprintcount == 0) return s;
313 /* Get a new block of store guaranteed big enough to hold the
316 tt = ss = store_get(length + nonprintcount * 3 + 1, is_tainted(s));
318 /* Copy everything, escaping non printers. */
324 && (!(flags & SP_TAB) || c != '\t')
325 && (!(flags & SP_SPACE) || c != ' ')
333 case '\n': *tt++ = 'n'; break;
334 case '\r': *tt++ = 'r'; break;
335 case '\b': *tt++ = 'b'; break;
336 case '\v': *tt++ = 'v'; break;
337 case '\f': *tt++ = 'f'; break;
338 case '\t': *tt++ = 't'; break;
339 default: sprintf(CS tt, "%03o", *t); tt += 3; break;
347 #endif /* COMPILE_UTILITY */
349 /*************************************************
350 * Undo printing escapes in string *
351 *************************************************/
353 /* This function is the reverse of string_printing2. It searches for
354 backslash characters and if any are found, it makes a new copy of the
355 string with escape sequences parsed. Otherwise it returns the original
361 Returns: string with printing escapes parsed back
365 string_unprinting(uschar *s)
367 uschar *p, *q, *r, *ss;
370 p = Ustrchr(s, '\\');
373 len = Ustrlen(s) + 1;
374 ss = store_get(len, is_tainted(s));
388 *q++ = string_interpret_escape((const uschar **)&p);
393 r = Ustrchr(p, '\\');
419 #if (defined(HAVE_LOCAL_SCAN) || defined(EXPAND_DLFUNC)) \
420 && !defined(MACRO_PREDEF) && !defined(COMPILE_UTILITY)
421 /*************************************************
422 * Copy and save string *
423 *************************************************/
426 Argument: string to copy
427 Returns: copy of string in new store with the same taint status
431 string_copy_function(const uschar *s)
433 return string_copy_taint(s, is_tainted(s));
436 /* As above, but explicitly specifying the result taint status
440 string_copy_taint_function(const uschar * s, BOOL tainted)
442 return string_copy_taint(s, tainted);
447 /*************************************************
448 * Copy and save string, given length *
449 *************************************************/
451 /* It is assumed the data contains no zeros. A zero is added
456 n number of characters
458 Returns: copy of string in new store
462 string_copyn_function(const uschar * s, int n)
464 return string_copyn(s, n);
469 /*************************************************
470 * Copy and save string in malloc'd store *
471 *************************************************/
473 /* This function assumes that memcpy() is faster than strcpy().
475 Argument: string to copy
476 Returns: copy of string in new store
480 string_copy_malloc(const uschar * s)
482 int len = Ustrlen(s) + 1;
483 uschar * ss = store_malloc(len);
490 /*************************************************
491 * Copy string if long, inserting newlines *
492 *************************************************/
494 /* If the given string is longer than 75 characters, it is copied, and within
495 the copy, certain space characters are converted into newlines.
497 Argument: pointer to the string
498 Returns: pointer to the possibly altered string
502 string_split_message(uschar * msg)
506 if (!msg || Ustrlen(msg) <= 75) return msg;
507 s = ss = msg = string_copy(msg);
512 while (i < 75 && *ss && *ss != '\n') ss++, i++;
524 if (t[-1] == ':') { tt = t; break; }
529 if (!tt) /* Can't split behind - try ahead */
534 if (*t == ' ' || *t == '\n')
540 if (!tt) break; /* Can't find anywhere to split */
551 /*************************************************
552 * Copy returned DNS domain name, de-escaping *
553 *************************************************/
555 /* If a domain name contains top-bit characters, some resolvers return
556 the fully qualified name with those characters turned into escapes. The
557 convention is a backslash followed by _decimal_ digits. We convert these
558 back into the original binary values. This will be relevant when
559 allow_utf8_domains is set true and UTF-8 characters are used in domain
560 names. Backslash can also be used to escape other characters, though we
561 shouldn't come across them in domain names.
563 Argument: the domain name string
564 Returns: copy of string in new store, de-escaped
568 string_copy_dnsdomain(uschar * s)
571 uschar * ss = yield = store_get(Ustrlen(s) + 1, TRUE); /* always treat as tainted */
577 else if (isdigit(s[1]))
579 *ss++ = (s[1] - '0')*100 + (s[2] - '0')*10 + s[3] - '0';
591 #ifndef COMPILE_UTILITY
592 /*************************************************
593 * Copy space-terminated or quoted string *
594 *************************************************/
596 /* This function copies from a string until its end, or until whitespace is
597 encountered, unless the string begins with a double quote, in which case the
598 terminating quote is sought, and escaping within the string is done. The length
599 of a de-quoted string can be no longer than the original, since escaping always
600 turns n characters into 1 character.
602 Argument: pointer to the pointer to the first character, which gets updated
603 Returns: the new string
607 string_dequote(const uschar ** sptr)
609 const uschar * s = * sptr;
612 /* First find the end of the string */
615 while (*s && !isspace(*s)) s++;
619 while (*s && *s != '\"')
621 if (*s == '\\') (void)string_interpret_escape(&s);
627 /* Get enough store to copy into */
629 t = yield = store_get(s - *sptr + 1, is_tainted(*sptr));
635 while (*s && !isspace(*s)) *t++ = *s++;
639 while (*s && *s != '\"')
641 *t++ = *s == '\\' ? string_interpret_escape(&s) : *s;
647 /* Update the pointer and return the terminated copy */
653 #endif /* COMPILE_UTILITY */
657 /*************************************************
658 * Format a string and save it *
659 *************************************************/
661 /* The formatting is done by string_vformat, which checks the length of
662 everything. Taint is taken from the worst of the arguments.
665 format a printf() format - deliberately char * rather than uschar *
666 because it will most usually be a literal string
667 func caller, for debug
668 line caller, for debug
669 ... arguments for format
671 Returns: pointer to fresh piece of store containing sprintf'ed string
675 string_sprintf_trc(const char * format, const uschar * func, unsigned line, ...)
677 #ifdef COMPILE_UTILITY
678 uschar buffer[STRING_SPRINTF_BUFFER_SIZE];
679 gstring gs = { .size = STRING_SPRINTF_BUFFER_SIZE, .ptr = 0, .s = buffer };
684 unsigned flags = SVFMT_REBUFFER|SVFMT_EXTEND;
689 g = string_vformat_trc(g, func, line, STRING_SPRINTF_BUFFER_SIZE,
694 log_write(0, LOG_MAIN|LOG_PANIC_DIE,
695 "string_sprintf expansion was longer than %d; format string was (%s)\n"
696 " called from %s %d\n",
697 STRING_SPRINTF_BUFFER_SIZE, format, func, line);
699 #ifdef COMPILE_UTILITY
700 return string_copyn(g->s, g->ptr);
702 gstring_release_unused(g);
703 return string_from_gstring(g);
709 /*************************************************
710 * Case-independent strncmp() function *
711 *************************************************/
717 n number of characters to compare
719 Returns: < 0, = 0, or > 0, according to the comparison
723 strncmpic(const uschar * s, const uschar * t, int n)
727 int c = tolower(*s++) - tolower(*t++);
734 /*************************************************
735 * Case-independent strcmp() function *
736 *************************************************/
743 Returns: < 0, = 0, or > 0, according to the comparison
747 strcmpic(const uschar * s, const uschar * t)
751 int c = tolower(*s++) - tolower(*t++);
752 if (c != 0) return c;
758 /*************************************************
759 * Case-independent strstr() function *
760 *************************************************/
762 /* The third argument specifies whether whitespace is required
763 to follow the matched string.
767 t substring to search for
768 space_follows if TRUE, match only if whitespace follows
770 Returns: pointer to substring in string, or NULL if not found
774 strstric(const uschar * s, const uschar * t, BOOL space_follows)
776 const uschar * p = t;
777 uschar * yield = NULL;
778 int cl = tolower(*p);
779 int cu = toupper(*p);
783 if (*s == cl || *s == cu)
785 if (!yield) yield = s;
788 if (!space_follows || s[1] == ' ' || s[1] == '\n' ) return yield;
810 #ifdef COMPILE_UTILITY
811 /* Dummy version for this function; it should never be called */
813 gstring_grow(gstring * g, int count)
821 #ifndef COMPILE_UTILITY
822 /*************************************************
823 * Get next string from separated list *
824 *************************************************/
826 /* Leading and trailing space is removed from each item. The separator in the
827 list is controlled by the int pointed to by the separator argument as follows:
829 If the value is > 0 it is used as the separator. This is typically used for
830 sublists such as slash-separated options. The value is always a printing
833 (If the value is actually > UCHAR_MAX there is only one item in the list.
834 This is used for some cases when called via functions that sometimes
835 plough through lists, and sometimes are given single items.)
837 If the value is <= 0, the string is inspected for a leading <x, where x is an
838 ispunct() or an iscntrl() character. If found, x is used as the separator. If
841 (a) if separator == 0, ':' is used
842 (b) if separator <0, -separator is used
844 In all cases the value of the separator that is used is written back to the
845 int so that it is used on subsequent calls as we progress through the list.
847 A literal ispunct() separator can be represented in an item by doubling, but
848 there is no way to include an iscntrl() separator as part of the data.
851 listptr points to a pointer to the current start of the list; the
852 pointer gets updated to point after the end of the next item
853 separator a pointer to the separator character in an int (see above)
854 buffer where to put a copy of the next string in the list; or
855 NULL if the next string is returned in new memory
856 Note that if the list is tainted then a provided buffer must be
857 also (else we trap, with a message referencing the callsite).
858 If we do the allocation, taint is handled there.
859 buflen when buffer is not NULL, the size of buffer; otherwise ignored
861 func caller, for debug
862 line caller, for debug
864 Returns: pointer to buffer, containing the next substring,
865 or NULL if no more substrings
869 string_nextinlist_trc(const uschar ** listptr, int * separator, uschar * buffer,
870 int buflen, const uschar * func, int line)
872 int sep = *separator;
873 const uschar * s = *listptr;
878 /* This allows for a fixed specified separator to be an iscntrl() character,
879 but at the time of implementation, this is never the case. However, it's best
880 to be conservative. */
882 while (isspace(*s) && *s != sep) s++;
884 /* A change of separator is permitted, so look for a leading '<' followed by an
885 allowed character. */
889 if (*s == '<' && (ispunct(s[1]) || iscntrl(s[1])))
893 while (isspace(*s) && *s != sep) s++;
896 sep = sep ? -sep : ':';
900 /* An empty string has no list elements */
902 if (!*s) return NULL;
904 /* Note whether whether or not the separator is an iscntrl() character. */
906 sep_is_special = iscntrl(sep);
908 /* Handle the case when a buffer is provided. */
913 if (is_tainted(s) && !is_tainted(buffer))
914 die_tainted(US"string_nextinlist", func, line);
917 if (*s == sep && (*(++s) != sep || sep_is_special)) break;
918 if (p < buflen - 1) buffer[p++] = *s;
920 while (p > 0 && isspace(buffer[p-1])) p--;
924 /* Handle the case when a buffer is not provided. */
930 /* We know that *s != 0 at this point. However, it might be pointing to a
931 separator, which could indicate an empty string, or (if an ispunct()
932 character) could be doubled to indicate a separator character as data at the
933 start of a string. Avoid getting working memory for an empty item. */
936 if (*++s != sep || sep_is_special)
939 return string_copy(US"");
942 /* Not an empty string; the first character is guaranteed to be a data
948 for (ss = s + 1; *ss && *ss != sep; ) ss++;
949 g = string_catn(g, s, ss-s);
951 if (!*s || *++s != sep || sep_is_special) break;
954 /* Trim trailing spaces from the returned string */
956 /* while (g->ptr > 0 && isspace(g->s[g->ptr-1])) g->ptr--; */
957 while ( g->ptr > 0 && isspace(g->s[g->ptr-1])
958 && (g->ptr == 1 || g->s[g->ptr-2] != '\\') )
960 buffer = string_from_gstring(g);
961 gstring_release_unused_trc(g, CCS func, line);
964 /* Update the current pointer and return the new string */
971 static const uschar *
972 Ustrnchr(const uschar * s, int c, unsigned * len)
977 if (!*s) return NULL;
990 /************************************************
991 * Add element to separated list *
992 ************************************************/
993 /* This function is used to build a list, returning an allocated null-terminated
994 growable string. The given element has any embedded separator characters
997 Despite having the same growable-string interface as string_cat() the list is
998 always returned null-terminated.
1001 list expanding-string for the list that is being built, or NULL
1002 if this is a new list that has no contents yet
1003 sep list separator character
1004 ele new element to be appended to the list
1006 Returns: pointer to the start of the list, changed if copied for expansion.
1010 string_append_listele(gstring * list, uschar sep, const uschar * ele)
1014 if (list && list->ptr)
1015 list = string_catn(list, &sep, 1);
1017 while((sp = Ustrchr(ele, sep)))
1019 list = string_catn(list, ele, sp-ele+1);
1020 list = string_catn(list, &sep, 1);
1023 list = string_cat(list, ele);
1024 (void) string_from_gstring(list);
1030 string_append_listele_n(gstring * list, uschar sep, const uschar * ele,
1035 if (list && list->ptr)
1036 list = string_catn(list, &sep, 1);
1038 while((sp = Ustrnchr(ele, sep, &len)))
1040 list = string_catn(list, ele, sp-ele+1);
1041 list = string_catn(list, &sep, 1);
1045 list = string_catn(list, ele, len);
1046 (void) string_from_gstring(list);
1052 /* A slightly-bogus listmaker utility; the separator is a string so
1053 can be multiple chars - there is no checking for the element content
1054 containing any of the separator. */
1057 string_append2_listele_n(gstring * list, const uschar * sepstr,
1058 const uschar * ele, unsigned len)
1060 if (list && list->ptr)
1061 list = string_cat(list, sepstr);
1063 list = string_catn(list, ele, len);
1064 (void) string_from_gstring(list);
1070 /************************************************/
1071 /* Add more space to a growable-string. The caller should check
1072 first if growth is required. The gstring struct is modified on
1073 return; specifically, the string-base-pointer may have been changed.
1076 g the growable-string
1077 count amount needed for g->ptr to increase by
1081 gstring_grow(gstring * g, int count)
1084 int oldsize = g->size;
1085 BOOL tainted = is_tainted(g->s);
1087 /* Mostly, string_cat() is used to build small strings of a few hundred
1088 characters at most. There are times, however, when the strings are very much
1089 longer (for example, a lookup that returns a vast number of alias addresses).
1090 To try to keep things reasonable, we use increments whose size depends on the
1091 existing length of the string. */
1093 unsigned inc = oldsize < 4096 ? 127 : 1023;
1095 if (g->ptr < 0 || g->ptr > g->size || g->size >= INT_MAX/2)
1096 log_write(0, LOG_MAIN|LOG_PANIC_DIE,
1097 "internal error in gstring_grow (ptr %d size %d)", g->ptr, g->size);
1099 if (count <= 0) return;
1101 if (count >= INT_MAX/2 - g->ptr)
1102 log_write(0, LOG_MAIN|LOG_PANIC_DIE,
1103 "internal error in gstring_grow (ptr %d count %d)", g->ptr, count);
1105 g->size = (p + count + inc + 1) & ~inc; /* one for a NUL */
1107 /* Try to extend an existing allocation. If the result of calling
1108 store_extend() is false, either there isn't room in the current memory block,
1109 or this string is not the top item on the dynamic store stack. We then have
1110 to get a new chunk of store and copy the old string. When building large
1111 strings, it is helpful to call store_release() on the old string, to release
1112 memory blocks that have become empty. (The block will be freed if the string
1113 is at its start.) However, we can do this only if we know that the old string
1114 was the last item on the dynamic memory stack. This is the case if it matches
1117 if (!store_extend(g->s, tainted, oldsize, g->size))
1118 g->s = store_newblock(g->s, tainted, g->size, p);
1123 /*************************************************
1124 * Add chars to string *
1125 *************************************************/
1126 /* This function is used when building up strings of unknown length. Room is
1127 always left for a terminating zero to be added to the string that is being
1128 built. This function does not require the string that is being added to be NUL
1129 terminated, because the number of characters to add is given explicitly. It is
1130 sometimes called to extract parts of other strings.
1133 g growable-string that is being built, or NULL if not assigned yet
1134 s points to characters to add
1135 count count of characters to add; must not exceed the length of s, if s
1138 Returns: growable string, changed if copied for expansion.
1139 Note that a NUL is not added, though space is left for one. This is
1140 because string_cat() is often called multiple times to build up a
1141 string - there's no point adding the NUL till the end.
1142 NULL is a possible return.
1145 /* coverity[+alloc] */
1148 string_catn(gstring * g, const uschar *s, int count)
1151 BOOL srctaint = is_tainted(s);
1154 log_write(0, LOG_MAIN|LOG_PANIC_DIE,
1155 "internal error in string_catn (count %d)", count);
1156 if (count == 0) return g;
1160 unsigned inc = count < 4096 ? 127 : 1023;
1161 unsigned size = ((count + inc) & ~inc) + 1; /* round up requested count */
1162 g = string_get_tainted(size, srctaint);
1164 else if (srctaint && !is_tainted(g->s))
1165 gstring_rebuffer(g);
1167 if (g->ptr < 0 || g->ptr > g->size)
1168 log_write(0, LOG_MAIN|LOG_PANIC_DIE,
1169 "internal error in string_catn (ptr %d size %d)", g->ptr, g->size);
1172 if (count >= g->size - p)
1173 gstring_grow(g, count);
1175 /* Because we always specify the exact number of characters to copy, we can
1176 use memcpy(), which is likely to be more efficient than strncopy() because the
1177 latter has to check for zero bytes. */
1179 memcpy(g->s + p, s, count);
1186 string_cat(gstring * g, const uschar * s)
1188 return string_catn(g, s, Ustrlen(s));
1193 /*************************************************
1194 * Append strings to another string *
1195 *************************************************/
1197 /* This function can be used to build a string from many other strings.
1198 It calls string_cat() to do the dirty work.
1201 g growable-string that is being built, or NULL if not yet assigned
1202 count the number of strings to append
1203 ... "count" uschar* arguments, which must be valid zero-terminated
1206 Returns: growable string, changed if copied for expansion.
1207 The string is not zero-terminated - see string_cat() above.
1210 __inline__ gstring *
1211 string_append(gstring * g, int count, ...)
1215 va_start(ap, count);
1218 uschar * t = va_arg(ap, uschar *);
1219 g = string_cat(g, t);
1229 /*************************************************
1230 * Format a string with length checks *
1231 *************************************************/
1233 /* This function is used to format a string with checking of the length of the
1234 output for all conversions. It protects Exim from absent-mindedness when
1235 calling functions like debug_printf and string_sprintf, and elsewhere. There
1236 are two different entry points to what is actually the same function, depending
1237 on whether the variable length list of data arguments are given explicitly or
1240 The formats are the usual printf() ones, with some omissions (never used) and
1241 three additions for strings: %S forces lower case, %T forces upper case, and
1242 %#s or %#S prints nothing for a NULL string. Without the # "NULL" is printed
1243 (useful in debugging). There is also the addition of %D and %M, which insert
1244 the date in the form used for datestamped log files.
1247 buffer a buffer in which to put the formatted string
1248 buflen the length of the buffer
1249 format the format string - deliberately char * and not uschar *
1250 ... or ap variable list of supplementary arguments
1252 Returns: TRUE if the result fitted in the buffer
1256 string_format_trc(uschar * buffer, int buflen,
1257 const uschar * func, unsigned line, const char * format, ...)
1259 gstring g = { .size = buflen, .ptr = 0, .s = buffer }, * gp;
1261 va_start(ap, format);
1262 gp = string_vformat_trc(&g, func, line, STRING_SPRINTF_BUFFER_SIZE,
1272 /* Build or append to a growing-string, sprintf-style.
1276 func called-from function name, for debug
1277 line called-from file line number, for debug
1278 limit maximum string size
1280 format printf-like format string
1281 ap variable-args pointer
1284 SVFMT_EXTEND buffer can be created or exteded as needed
1285 SVFMT_REBUFFER buffer can be recopied to tainted mem as needed
1286 SVFMT_TAINT_NOCHK do not check inputs for taint
1288 If the "extend" flag is true, the string passed in can be NULL,
1289 empty, or non-empty. Growing is subject to an overall limit given
1290 by the limit argument.
1292 If the "extend" flag is false, the string passed in may not be NULL,
1293 will not be grown, and is usable in the original place after return.
1294 The return value can be NULL to signify overflow.
1296 Returns the possibly-new (if copy for growth or taint-handling was needed)
1297 string, not nul-terminated.
1301 string_vformat_trc(gstring * g, const uschar * func, unsigned line,
1302 unsigned size_limit, unsigned flags, const char * format, va_list ap)
1304 enum ltypes { L_NORMAL=1, L_SHORT=2, L_LONG=3, L_LONGLONG=4, L_LONGDOUBLE=5, L_SIZE=6 };
1306 int width, precision, off, lim, need;
1307 const char * fp = format; /* Deliberately not unsigned */
1308 BOOL dest_tainted = FALSE;
1310 string_datestamp_offset = -1; /* Datestamp not inserted */
1311 string_datestamp_length = 0; /* Datestamp not inserted */
1312 string_datestamp_type = 0; /* Datestamp not inserted */
1314 #ifdef COMPILE_UTILITY
1315 assert(!(flags & SVFMT_EXTEND));
1319 /* Ensure we have a string, to save on checking later */
1320 if (!g) g = string_get(16);
1321 else if (!(flags & SVFMT_TAINT_NOCHK)) dest_tainted = is_tainted(g->s);
1323 if (!(flags & SVFMT_TAINT_NOCHK) && !dest_tainted && is_tainted(format))
1325 #ifndef MACRO_PREDEF
1326 if (!(flags & SVFMT_REBUFFER))
1327 die_tainted(US"string_vformat", func, line);
1329 gstring_rebuffer(g);
1330 dest_tainted = TRUE;
1332 #endif /*!COMPILE_UTILITY*/
1334 lim = g->size - 1; /* leave one for a nul */
1335 off = g->ptr; /* remember initial offset in gstring */
1337 /* Scan the format and handle the insertions */
1341 int length = L_NORMAL;
1344 const char *null = "NULL"; /* ) These variables */
1345 const char *item_start, *s; /* ) are deliberately */
1346 char newformat[16]; /* ) not unsigned */
1347 char * gp = CS g->s + g->ptr; /* ) */
1349 /* Non-% characters just get copied verbatim */
1353 /* Avoid string_copyn() due to COMPILE_UTILITY */
1354 if ((need = g->ptr + 1) > lim)
1356 if (!(flags & SVFMT_EXTEND) || need > size_limit) return NULL;
1360 g->s[g->ptr++] = (uschar) *fp++;
1364 /* Deal with % characters. Pick off the width and precision, for checking
1365 strings, skipping over the flag and modifier characters. */
1368 width = precision = -1;
1370 if (strchr("-+ #0", *(++fp)) != NULL)
1372 if (*fp == '#') null = "";
1376 if (isdigit((uschar)*fp))
1378 width = *fp++ - '0';
1379 while (isdigit((uschar)*fp)) width = width * 10 + *fp++ - '0';
1381 else if (*fp == '*')
1383 width = va_arg(ap, int);
1390 precision = va_arg(ap, int);
1394 for (precision = 0; isdigit((uschar)*fp); fp++)
1395 precision = precision*10 + *fp - '0';
1397 /* Skip over 'h', 'L', 'l', 'll' and 'z', remembering the item length */
1400 { fp++; length = L_SHORT; }
1401 else if (*fp == 'L')
1402 { fp++; length = L_LONGDOUBLE; }
1403 else if (*fp == 'l')
1405 { fp += 2; length = L_LONGLONG; }
1407 { fp++; length = L_LONG; }
1408 else if (*fp == 'z')
1409 { fp++; length = L_SIZE; }
1411 /* Handle each specific format type. */
1416 nptr = va_arg(ap, int *);
1417 *nptr = g->ptr - off;
1425 width = length > L_LONG ? 24 : 12;
1426 if ((need = g->ptr + width) > lim)
1428 if (!(flags & SVFMT_EXTEND) || need >= size_limit) return NULL;
1429 gstring_grow(g, width);
1431 gp = CS g->s + g->ptr;
1433 strncpy(newformat, item_start, fp - item_start);
1434 newformat[fp - item_start] = 0;
1436 /* Short int is promoted to int when passing through ..., so we must use
1437 int for va_arg(). */
1443 g->ptr += sprintf(gp, newformat, va_arg(ap, int)); break;
1445 g->ptr += sprintf(gp, newformat, va_arg(ap, long int)); break;
1447 g->ptr += sprintf(gp, newformat, va_arg(ap, LONGLONG_T)); break;
1449 g->ptr += sprintf(gp, newformat, va_arg(ap, size_t)); break;
1456 if ((need = g->ptr + 24) > lim)
1458 if (!(flags & SVFMT_EXTEND || need >= size_limit)) return NULL;
1459 gstring_grow(g, 24);
1461 gp = CS g->s + g->ptr;
1463 /* sprintf() saying "(nil)" for a null pointer seems unreliable.
1464 Handle it explicitly. */
1465 if ((ptr = va_arg(ap, void *)))
1467 strncpy(newformat, item_start, fp - item_start);
1468 newformat[fp - item_start] = 0;
1469 g->ptr += sprintf(gp, newformat, ptr);
1472 g->ptr += sprintf(gp, "(nil)");
1476 /* %f format is inherently insecure if the numbers that it may be
1477 handed are unknown (e.g. 1e300). However, in Exim, %f is used for
1478 printing load averages, and these are actually stored as integers
1479 (load average * 1000) so the size of the numbers is constrained.
1480 It is also used for formatting sending rates, where the simplicity
1481 of the format prevents overflow. */
1488 if (precision < 0) precision = 6;
1489 if ((need = g->ptr + precision + 8) > lim)
1491 if (!(flags & SVFMT_EXTEND || need >= size_limit)) return NULL;
1492 gstring_grow(g, precision+8);
1494 gp = CS g->s + g->ptr;
1496 strncpy(newformat, item_start, fp - item_start);
1497 newformat[fp-item_start] = 0;
1498 if (length == L_LONGDOUBLE)
1499 g->ptr += sprintf(gp, newformat, va_arg(ap, long double));
1501 g->ptr += sprintf(gp, newformat, va_arg(ap, double));
1507 if ((need = g->ptr + 1) > lim)
1509 if (!(flags & SVFMT_EXTEND || need >= size_limit)) return NULL;
1513 g->s[g->ptr++] = (uschar) '%';
1517 if ((need = g->ptr + 1) > lim)
1519 if (!(flags & SVFMT_EXTEND || need >= size_limit)) return NULL;
1523 g->s[g->ptr++] = (uschar) va_arg(ap, int);
1526 case 'D': /* Insert daily datestamp for log file names */
1527 s = CS tod_stamp(tod_log_datestamp_daily);
1528 string_datestamp_offset = g->ptr; /* Passed back via global */
1529 string_datestamp_length = Ustrlen(s); /* Passed back via global */
1530 string_datestamp_type = tod_log_datestamp_daily;
1531 slen = string_datestamp_length;
1534 case 'M': /* Insert monthly datestamp for log file names */
1535 s = CS tod_stamp(tod_log_datestamp_monthly);
1536 string_datestamp_offset = g->ptr; /* Passed back via global */
1537 string_datestamp_length = Ustrlen(s); /* Passed back via global */
1538 string_datestamp_type = tod_log_datestamp_monthly;
1539 slen = string_datestamp_length;
1543 case 'S': /* Forces *lower* case */
1544 case 'T': /* Forces *upper* case */
1545 s = va_arg(ap, char *);
1550 if (!(flags & SVFMT_TAINT_NOCHK) && !dest_tainted && is_tainted(s))
1551 if (flags & SVFMT_REBUFFER)
1553 gstring_rebuffer(g);
1554 gp = CS g->s + g->ptr;
1555 dest_tainted = TRUE;
1557 #ifndef MACRO_PREDEF
1559 die_tainted(US"string_vformat", func, line);
1562 INSERT_STRING: /* Come to from %D or %M above */
1565 BOOL truncated = FALSE;
1567 /* If the width is specified, check that there is a precision
1568 set; if not, set it to the width to prevent overruns of long
1573 if (precision < 0) precision = width;
1576 /* If a width is not specified and the precision is specified, set
1577 the width to the precision, or the string length if shorted. */
1579 else if (precision >= 0)
1580 width = precision < slen ? precision : slen;
1582 /* If neither are specified, set them both to the string length. */
1585 width = precision = slen;
1587 if ((need = g->ptr + width) >= size_limit || !(flags & SVFMT_EXTEND))
1589 if (g->ptr == lim) return NULL;
1593 width = precision = lim - g->ptr - 1;
1594 if (width < 0) width = 0;
1595 if (precision < 0) precision = 0;
1598 else if (need > lim)
1600 gstring_grow(g, width);
1602 gp = CS g->s + g->ptr;
1605 g->ptr += sprintf(gp, "%*.*s", width, precision, s);
1607 while (*gp) { *gp = tolower(*gp); gp++; }
1608 else if (fp[-1] == 'T')
1609 while (*gp) { *gp = toupper(*gp); gp++; }
1611 if (truncated) return NULL;
1615 /* Some things are never used in Exim; also catches junk. */
1618 strncpy(newformat, item_start, fp - item_start);
1619 newformat[fp-item_start] = 0;
1620 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "string_format: unsupported type "
1621 "in \"%s\" in \"%s\"", newformat, format);
1626 if (g->ptr > g->size)
1627 log_write(0, LOG_MAIN|LOG_PANIC_DIE,
1628 "string_format internal error: caller %s %d", func, line);
1634 #ifndef COMPILE_UTILITY
1635 /*************************************************
1636 * Generate an "open failed" message *
1637 *************************************************/
1639 /* This function creates a message after failure to open a file. It includes a
1640 string supplied as data, adds the strerror() text, and if the failure was
1641 "Permission denied", reads and includes the euid and egid.
1644 format a text format string - deliberately not uschar *
1645 func caller, for debug
1646 line caller, for debug
1647 ... arguments for the format string
1649 Returns: a message, in dynamic store
1653 string_open_failed_trc(const uschar * func, unsigned line,
1654 const char * format, ...)
1657 gstring * g = string_get(1024);
1659 g = string_catn(g, US"failed to open ", 15);
1661 /* Use the checked formatting routine to ensure that the buffer
1662 does not overflow. It should not, since this is called only for internally
1663 specified messages. If it does, the message just gets truncated, and there
1664 doesn't seem much we can do about that. */
1666 va_start(ap, format);
1667 (void) string_vformat_trc(g, func, line, STRING_SPRINTF_BUFFER_SIZE,
1668 SVFMT_REBUFFER, format, ap);
1671 g = string_catn(g, US": ", 2);
1672 g = string_cat(g, US strerror(errno));
1674 if (errno == EACCES)
1676 int save_errno = errno;
1677 g = string_fmt_append(g, " (euid=%ld egid=%ld)",
1678 (long int)geteuid(), (long int)getegid());
1681 gstring_release_unused(g);
1682 return string_from_gstring(g);
1689 /* qsort(3), currently used to sort the environment variables
1690 for -bP environment output, needs a function to compare two pointers to string
1691 pointers. Here it is. */
1694 string_compare_by_pointer(const void *a, const void *b)
1696 return Ustrcmp(* CUSS a, * CUSS b);
1698 #endif /* COMPILE_UTILITY */
1703 /*************************************************
1704 **************************************************
1705 * Stand-alone test program *
1706 **************************************************
1707 *************************************************/
1714 printf("Testing is_ip_address\n");
1717 while (fgets(CS buffer, sizeof(buffer), stdin) != NULL)
1720 buffer[Ustrlen(buffer) - 1] = 0;
1721 printf("%d\n", string_is_ip_address(buffer, NULL));
1722 printf("%d %d %s\n", string_is_ip_address(buffer, &offset), offset, buffer);
1725 printf("Testing string_nextinlist\n");
1727 while (fgets(CS buffer, sizeof(buffer), stdin) != NULL)
1729 uschar *list = buffer;
1737 sep1 = sep2 = list[1];
1744 uschar *item1 = string_nextinlist(&lp1, &sep1, item, sizeof(item));
1745 uschar *item2 = string_nextinlist(&lp2, &sep2, NULL, 0);
1747 if (item1 == NULL && item2 == NULL) break;
1748 if (item == NULL || item2 == NULL || Ustrcmp(item1, item2) != 0)
1750 printf("***ERROR\nitem1=\"%s\"\nitem2=\"%s\"\n",
1751 (item1 == NULL)? "NULL" : CS item1,
1752 (item2 == NULL)? "NULL" : CS item2);
1755 else printf(" \"%s\"\n", CS item1);
1759 /* This is a horrible lash-up, but it serves its purpose. */
1761 printf("Testing string_format\n");
1763 while (fgets(CS buffer, sizeof(buffer), stdin) != NULL)
1766 long long llargs[3];
1776 buffer[Ustrlen(buffer) - 1] = 0;
1778 s = Ustrchr(buffer, ',');
1779 if (s == NULL) s = buffer + Ustrlen(buffer);
1781 Ustrncpy(format, buffer, s - buffer);
1782 format[s-buffer] = 0;
1789 s = Ustrchr(ss, ',');
1790 if (s == NULL) s = ss + Ustrlen(ss);
1794 Ustrncpy(outbuf, ss, s-ss);
1795 if (Ustrchr(outbuf, '.') != NULL)
1798 dargs[n++] = Ustrtod(outbuf, NULL);
1800 else if (Ustrstr(outbuf, "ll") != NULL)
1803 llargs[n++] = strtoull(CS outbuf, NULL, 10);
1807 args[n++] = (void *)Uatoi(outbuf);
1811 else if (Ustrcmp(ss, "*") == 0)
1813 args[n++] = (void *)(&count);
1819 uschar *sss = malloc(s - ss + 1);
1820 Ustrncpy(sss, ss, s-ss);
1827 if (!dflag && !llflag)
1828 printf("%s\n", string_format(outbuf, sizeof(outbuf), CS format,
1829 args[0], args[1], args[2])? "True" : "False");
1832 printf("%s\n", string_format(outbuf, sizeof(outbuf), CS format,
1833 dargs[0], dargs[1], dargs[2])? "True" : "False");
1835 else printf("%s\n", string_format(outbuf, sizeof(outbuf), CS format,
1836 llargs[0], llargs[1], llargs[2])? "True" : "False");
1838 printf("%s\n", CS outbuf);
1839 if (countset) printf("count=%d\n", count);
1846 /* End of string.c */