From: Christos Zoulas Date: Thu, 1 Jan 2015 17:07:34 +0000 (+0000) Subject: Add indirect relative offsets; make Exif use them. All other indirect magic X-Git-Tag: FILE5_22~4 X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=24afd020b48d38d90350579b707773bf9d08c6ba;p=file Add indirect relative offsets; make Exif use them. All other indirect magic is absolute by default. --- diff --git a/ChangeLog b/ChangeLog index 7e501baa..6552c0a9 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,7 @@ +2015-01-01 12:01 Christos Zoulas + + * add indirect relative for TIFF/Exif + 2014-12-16 18:10 Christos Zoulas * restructure elf note printing to avoid repeated messages diff --git a/doc/magic.man b/doc/magic.man index 66d3b173..86bbda0a 100644 --- a/doc/magic.man +++ b/doc/magic.man @@ -1,5 +1,5 @@ -.\" $File: magic.man,v 1.83 2014/06/03 17:36:13 christos Exp $ -.Dd June 3, 2014 +.\" $File: magic.man,v 1.84 2014/06/03 19:01:34 christos Exp $ +.Dd January 1, 2015 .Dt MAGIC __FSECTION__ .Os .\" install as magic.4 on USG, magic.5 on V7, Berkeley and Linux systems. @@ -200,6 +200,11 @@ interpreted as a UNIX-style date, but interpreted as local time rather than UTC. .It Dv indirect Starting at the given offset, consult the magic database again. +The offset of th +.Dv indirect +magic is by default absolute in the file, but one can specify +.Dv /r +to indicate that the offset is relative from the beginning of the entry. .It Dv name Define a .Dq named diff --git a/magic/Magdir/jpeg b/magic/Magdir/jpeg index 81b0aa69..48a07f2e 100644 --- a/magic/Magdir/jpeg +++ b/magic/Magdir/jpeg @@ -1,6 +1,6 @@ #------------------------------------------------------------------------------ -# $File: jpeg,v 1.22 2015/01/01 02:57:40 christos Exp $ +# $File: jpeg,v 1.23 2015/01/01 04:17:41 christos Exp $ # JPEG images # SunOS 5.5.1 had # @@ -32,7 +32,7 @@ >>18 byte !0 \b, thumbnail %dx >>>19 byte x \b%d >6 string Exif \b, Exif standard: [ ->>12 indirect x +>>12 indirect/r x >>12 string x \b] # Jump to the first segment @@ -72,7 +72,7 @@ >0 beshort 0xFFE1 #>>(2.S+2) use jpeg_segment >>4 string Exif \b, Exif Standard: [ ->>>10 indirect x +>>>10 indirect/r x >>>10 string x \b] # Application specific markers diff --git a/src/apprentice.c b/src/apprentice.c index ac098263..02e081fb 100644 --- a/src/apprentice.c +++ b/src/apprentice.c @@ -32,7 +32,7 @@ #include "file.h" #ifndef lint -FILE_RCSID("@(#)$File: apprentice.c,v 1.227 2014/11/28 02:46:39 christos Exp $") +FILE_RCSID("@(#)$File: apprentice.c,v 1.228 2014/12/16 23:18:40 christos Exp $") #endif /* lint */ #include "magic.h" @@ -1605,6 +1605,145 @@ check_cond(struct magic_set *ms, int cond, uint32_t cont_level) } #endif /* ENABLE_CONDITIONALS */ +private int +parse_indirect_modifier(struct magic_set *ms, struct magic *m, const char **lp) +{ + const char *l = *lp; + + while (!isspace((unsigned char)*++l)) + switch (*l) { + case CHAR_INDIRECT_RELATIVE: + m->str_flags |= INDIRECT_RELATIVE; + break; + default: + if (ms->flags & MAGIC_CHECK) + file_magwarn(ms, "indirect modifier `%c' " + "invalid", *l); + *lp = l; + return -1; + } + *lp = l; + return 0; +} + +private void +parse_op_modifier(struct magic_set *ms, struct magic *m, const char **lp, + int op) +{ + const char *l = *lp; + char *t; + uint64_t val; + + ++l; + m->mask_op |= op; + val = (uint64_t)strtoull(l, &t, 0); + l = t; + m->num_mask = file_signextend(ms, m, val); + eatsize(&l); + *lp = l; +} + +private int +parse_string_modifier(struct magic_set *ms, struct magic *m, const char **lp) +{ + const char *l = *lp; + char *t; + int have_range = 0; + + while (!isspace((unsigned char)*++l)) { + switch (*l) { + case '0': case '1': case '2': + case '3': case '4': case '5': + case '6': case '7': case '8': + case '9': + if (have_range && (ms->flags & MAGIC_CHECK)) + file_magwarn(ms, "multiple ranges"); + have_range = 1; + m->str_range = CAST(uint32_t, strtoul(l, &t, 0)); + if (m->str_range == 0) + file_magwarn(ms, "zero range"); + l = t - 1; + break; + case CHAR_COMPACT_WHITESPACE: + m->str_flags |= STRING_COMPACT_WHITESPACE; + break; + case CHAR_COMPACT_OPTIONAL_WHITESPACE: + m->str_flags |= STRING_COMPACT_OPTIONAL_WHITESPACE; + break; + case CHAR_IGNORE_LOWERCASE: + m->str_flags |= STRING_IGNORE_LOWERCASE; + break; + case CHAR_IGNORE_UPPERCASE: + m->str_flags |= STRING_IGNORE_UPPERCASE; + break; + case CHAR_REGEX_OFFSET_START: + m->str_flags |= REGEX_OFFSET_START; + break; + case CHAR_BINTEST: + m->str_flags |= STRING_BINTEST; + break; + case CHAR_TEXTTEST: + m->str_flags |= STRING_TEXTTEST; + break; + case CHAR_TRIM: + m->str_flags |= STRING_TRIM; + break; + case CHAR_PSTRING_1_LE: +#define SET_LENGTH(a) m->str_flags = (m->str_flags & ~PSTRING_LEN) | (a) + if (m->type != FILE_PSTRING) + goto bad; + SET_LENGTH(PSTRING_1_LE); + break; + case CHAR_PSTRING_2_BE: + if (m->type != FILE_PSTRING) + goto bad; + SET_LENGTH(PSTRING_2_BE); + break; + case CHAR_PSTRING_2_LE: + if (m->type != FILE_PSTRING) + goto bad; + SET_LENGTH(PSTRING_2_LE); + break; + case CHAR_PSTRING_4_BE: + if (m->type != FILE_PSTRING) + goto bad; + SET_LENGTH(PSTRING_4_BE); + break; + case CHAR_PSTRING_4_LE: + switch (m->type) { + case FILE_PSTRING: + case FILE_REGEX: + break; + default: + goto bad; + } + SET_LENGTH(PSTRING_4_LE); + break; + case CHAR_PSTRING_LENGTH_INCLUDES_ITSELF: + if (m->type != FILE_PSTRING) + goto bad; + m->str_flags |= PSTRING_LENGTH_INCLUDES_ITSELF; + break; + default: + bad: + if (ms->flags & MAGIC_CHECK) + file_magwarn(ms, "string modifier `%c' " + "invalid", *l); + goto out; + } + /* allow multiple '/' for readability */ + if (l[1] == '/' && !isspace((unsigned char)l[2])) + l++; + } + if (string_modifier_check(ms, m) == -1) + goto out; + *lp = l; + return 0; +out: + *lp = l; + return -1; +} + /* * parse one line from magic file, put into magic[index++] if valid */ @@ -1874,118 +2013,27 @@ parse(struct magic_set *ms, struct magic_entry *me, const char *line, m->str_range = 0; m->str_flags = m->type == FILE_PSTRING ? PSTRING_1_LE : 0; if ((op = get_op(*l)) != -1) { - if (!IS_STRING(m->type)) { - uint64_t val; - ++l; - m->mask_op |= op; - val = (uint64_t)strtoull(l, &t, 0); - l = t; - m->num_mask = file_signextend(ms, m, val); - eatsize(&l); - } - else if (op == FILE_OPDIVIDE) { - int have_range = 0; - while (!isspace((unsigned char)*++l)) { - switch (*l) { - case '0': case '1': case '2': - case '3': case '4': case '5': - case '6': case '7': case '8': - case '9': - if (have_range && - (ms->flags & MAGIC_CHECK)) - file_magwarn(ms, - "multiple ranges"); - have_range = 1; - m->str_range = CAST(uint32_t, - strtoul(l, &t, 0)); - if (m->str_range == 0) - file_magwarn(ms, - "zero range"); - l = t - 1; - break; - case CHAR_COMPACT_WHITESPACE: - m->str_flags |= - STRING_COMPACT_WHITESPACE; - break; - case CHAR_COMPACT_OPTIONAL_WHITESPACE: - m->str_flags |= - STRING_COMPACT_OPTIONAL_WHITESPACE; - break; - case CHAR_IGNORE_LOWERCASE: - m->str_flags |= STRING_IGNORE_LOWERCASE; - break; - case CHAR_IGNORE_UPPERCASE: - m->str_flags |= STRING_IGNORE_UPPERCASE; - break; - case CHAR_REGEX_OFFSET_START: - m->str_flags |= REGEX_OFFSET_START; - break; - case CHAR_BINTEST: - m->str_flags |= STRING_BINTEST; - break; - case CHAR_TEXTTEST: - m->str_flags |= STRING_TEXTTEST; - break; - case CHAR_TRIM: - m->str_flags |= STRING_TRIM; - break; - case CHAR_PSTRING_1_LE: - if (m->type != FILE_PSTRING) - goto bad; - m->str_flags = (m->str_flags & ~PSTRING_LEN) | PSTRING_1_LE; - break; - case CHAR_PSTRING_2_BE: - if (m->type != FILE_PSTRING) - goto bad; - m->str_flags = (m->str_flags & ~PSTRING_LEN) | PSTRING_2_BE; - break; - case CHAR_PSTRING_2_LE: - if (m->type != FILE_PSTRING) - goto bad; - m->str_flags = (m->str_flags & ~PSTRING_LEN) | PSTRING_2_LE; - break; - case CHAR_PSTRING_4_BE: - if (m->type != FILE_PSTRING) - goto bad; - m->str_flags = (m->str_flags & ~PSTRING_LEN) | PSTRING_4_BE; - break; - case CHAR_PSTRING_4_LE: - switch (m->type) { - case FILE_PSTRING: - case FILE_REGEX: - break; - default: - goto bad; - } - m->str_flags = (m->str_flags & ~PSTRING_LEN) | PSTRING_4_LE; - break; - case CHAR_PSTRING_LENGTH_INCLUDES_ITSELF: - if (m->type != FILE_PSTRING) - goto bad; - m->str_flags |= PSTRING_LENGTH_INCLUDES_ITSELF; - break; - default: - bad: - if (ms->flags & MAGIC_CHECK) - file_magwarn(ms, - "string extension `%c' " - "invalid", *l); - return -1; - } - /* allow multiple '/' for readability */ - if (l[1] == '/' && - !isspace((unsigned char)l[2])) - l++; + if (IS_STRING(m->type)) { + int r; + + if (op != FILE_OPDIVIDE) { + if (ms->flags & MAGIC_CHECK) + file_magwarn(ms, + "invalid string/indirect op: " + "`%c'", *t); + return -1; } - if (string_modifier_check(ms, m) == -1) + + if (m->type == FILE_INDIRECT) + r = parse_indirect_modifier(ms, m, &l); + else + r = parse_string_modifier(ms, m, &l); + if (r == -1) return -1; - } - else { - if (ms->flags & MAGIC_CHECK) - file_magwarn(ms, "invalid string op: %c", *t); - return -1; - } + } else + parse_op_modifier(ms, m, &l, op); } + /* * We used to set mask to all 1's here, instead let's just not do * anything if mask = 0 (unless you have a better idea) diff --git a/src/file.h b/src/file.h index e977a2c4..9a780733 100644 --- a/src/file.h +++ b/src/file.h @@ -27,7 +27,7 @@ */ /* * file.h - definitions for file(1) program - * @(#)$File: file.h,v 1.162 2014/12/11 12:34:24 christos Exp $ + * @(#)$File: file.h,v 1.163 2014/12/16 23:18:40 christos Exp $ */ #ifndef __file_h__ @@ -234,6 +234,7 @@ struct magic { (t) == FILE_LESTRING16 || \ (t) == FILE_REGEX || \ (t) == FILE_SEARCH || \ + (t) == FILE_INDIRECT || \ (t) == FILE_NAME || \ (t) == FILE_USE) @@ -346,6 +347,8 @@ struct magic { #define STRING_IGNORE_CASE (STRING_IGNORE_LOWERCASE|STRING_IGNORE_UPPERCASE) #define STRING_DEFAULT_RANGE 100 +#define INDIRECT_RELATIVE BIT(0) +#define CHAR_INDIRECT_RELATIVE 'r' /* list of magic entries */ struct mlist { diff --git a/src/softmagic.c b/src/softmagic.c index 0bdfb377..29be5f9b 100644 --- a/src/softmagic.c +++ b/src/softmagic.c @@ -32,7 +32,7 @@ #include "file.h" #ifndef lint -FILE_RCSID("@(#)$File: softmagic.c,v 1.204 2014/12/11 12:34:24 christos Exp $") +FILE_RCSID("@(#)$File: softmagic.c,v 1.205 2015/01/01 04:12:23 christos Exp $") #endif /* lint */ #include "magic.h" @@ -1665,7 +1665,8 @@ mget(struct magic_set *ms, const unsigned char *s, struct magic *m, break; case FILE_INDIRECT: - offset += o; + if (m->str_flags & INDIRECT_RELATIVE) + offset += o; if (offset == 0) return 0;