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sortix--sortix/mkinitrd/rules.cpp
2016-02-07 22:20:36 +01:00

358 lines
8.5 KiB
C++

/*******************************************************************************
Copyright(C) Jonas 'Sortie' Termansen 2013.
This file is part of Sortix.
Sortix is free software: you can redistribute it and/or modify it under the
terms of the GNU General Public License as published by the Free Software
Foundation, either version 3 of the License, or (at your option) any later
version.
Sortix is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
details.
You should have received a copy of the GNU General Public License along
with Sortix. If not, see <http://www.gnu.org/licenses/>.
rules.cpp
Determines whether a given path is included in the filesystem.
*******************************************************************************/
#include <ctype.h>
#include <errno.h>
#include <error.h>
#include <libgen.h>
#include <stdarg.h>
#include <stddef.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include "rules.h"
static void error_fp(FILE* fp, int status, int errnum, const char* format, ...)
{
fprintf(fp, "%s: ", program_invocation_name);
va_list list;
va_start(list, format);
vfprintf(fp, format, list);
va_end(list);
if ( errnum )
fprintf(fp, ": %s", strerror(errnum));
fprintf(fp, "\n");
if ( status )
exit(status);
}
static const char* SkipCharacters(const char* str, char c)
{
while ( *str == c)
str++;
return str;
}
// /usr/bin/foobar match /usr = true
// /usr/bin/foobar match usr = false
// ///usr////bin//foobar match //usr// = true
// ///usr////bin//foobar match //usr//./evince = false
// TODO: Should this support . and .. too?
static bool PathMatchesPattern(const char* path, const char* pattern)
{
bool last_was_slash = false;
while ( true )
{
if ( !*pattern )
return !*path || last_was_slash;
if ( (last_was_slash = *pattern == '/') )
{
if ( *path == '/' )
{
path = SkipCharacters(path, '/');
pattern = SkipCharacters(pattern, '/');
continue;
}
return false;
}
if ( *pattern++ != *path++ )
return false;
}
}
InclusionRule::InclusionRule(const char* pattern, InclusionRuleType rule)
{
this->pattern = strdup(pattern);
this->rule = rule;
}
InclusionRule::~InclusionRule()
{
free(pattern);
}
bool InclusionRule::MatchesPath(const char* path) const
{
return PathMatchesPattern(path, pattern);
}
InclusionRules::InclusionRules()
{
rules = NULL;
num_rules = num_rules_allocated = 0;
default_inclusion = true;
}
InclusionRules::~InclusionRules()
{
for ( size_t i = 0; i < num_rules; i++ )
delete rules[i];
delete[] rules;
}
static int search_path(const void* a_ptr, const void* b_ptr)
{
const char* key = (const char*) a_ptr;
char* path = *(char**) b_ptr;
return strcmp(key, path);
}
bool InclusionRules::IncludesPath(const char* path) const
{
bool determined = false;
bool included = false;
for ( size_t i = 0; i < num_rules; i++ )
{
InclusionRule* rule = rules[i];
if ( !rule->MatchesPath(path) )
continue;
switch ( rules[i]->rule )
{
case RULE_INCLUDE:
included = true;
determined = true;
break;
case RULE_EXCLUDE:
included = false;
determined = true;
break;
}
}
if ( !determined )
included = default_inclusion;
if ( !included )
return false;
if ( manifest_used &&
!bsearch(path, manifest, manifest_used, sizeof(char*), search_path) )
return false;
return true;
}
bool InclusionRules::ChangeRulesAmount(size_t new_length)
{
size_t new_num_rules = new_length < num_rules ? new_length : num_rules;
for ( size_t i = new_num_rules; i < num_rules; i++ )
delete rules[i];
num_rules = new_num_rules;
InclusionRule** new_rules = new InclusionRule*[new_length];
for ( size_t i = 0; i < new_length && i < num_rules; i++ )
new_rules[i] = rules[i];
delete[] rules; rules = new_rules;
num_rules_allocated = new_length;
return true;
}
bool InclusionRules::AddRule(InclusionRule* rule)
{
if ( num_rules == num_rules_allocated )
{
size_t new_length = num_rules_allocated ? 2 * num_rules_allocated : 32;
if ( !ChangeRulesAmount(new_length) )
return false;
}
rules[num_rules++] = rule;
return true;
}
static const char* SkipWhitespace(const char* line)
{
while ( *line && isspace((unsigned char) *line) )
line++;
return line;
}
static char* SkipWhitespace(char* line)
{
return (char*) SkipWhitespace((const char*) line);
}
static bool IsLineComment(const char* line)
{
return !*line || *line == '#';
}
static const char* IsLineCommand(const char* line, const char* command)
{
while ( *line && isspace((unsigned char) *line) )
line++;
size_t cmdlen = strlen(command);
if ( strncmp(line, command, cmdlen) != 0 )
return NULL;
if ( line[cmdlen] && !isspace((unsigned char) line[cmdlen]) )
return NULL;
while ( line[cmdlen] && isspace((unsigned char) line[cmdlen]) )
cmdlen++;
return line + cmdlen;
}
bool InclusionRules::AddRulesFromFile(FILE* fp, FILE* err, const char* fpname)
{
size_t rules_at_start = num_rules;
size_t line_size;
size_t line_num = 0;
char* mem = NULL;
ssize_t line_len;
while ( 0 <= (line_len = getline(&mem, &line_size, fp)) )
{
char* line = mem;
line_num++;
if ( line_len && line[line_len-1] == '\n' )
line[line_len-1] = '\0';
line = SkipWhitespace(line);
if ( IsLineComment(line) )
continue;
const char* parameter;
if ( (parameter = IsLineCommand(line, "default")) )
{
bool value;
if ( !strcmp(parameter, "true") )
value = true;
else if ( !strcmp(parameter, "false") )
value = false;
else
{
error_fp(err, 0, 0, "%s:%zu: not a boolean '%s'", fpname,
line_num, parameter);
goto error_out;
}
if ( !default_inclusion_determined )
default_inclusion = value,
default_inclusion_determined = true;
else
default_inclusion = default_inclusion || value;
}
else if ( (parameter = IsLineCommand(line, "exclude")) ||
(parameter = IsLineCommand(line, "include")) )
{
if ( !*parameter )
{
error_fp(err, 0, 0, "%s:%zu: no parameter given", fpname,
line_num);
goto error_out;
}
const char* pattern = parameter;
InclusionRuleType type = line[0] == 'e' ? RULE_EXCLUDE : RULE_INCLUDE;
InclusionRule* rule = new InclusionRule(pattern, type);
if ( !AddRule(rule) )
goto error_out_errno;
}
else
{
error_fp(err, 0, 0, "%s:%zu: line not understood: '%s'", fpname,
line_num, line);
goto error_out;
}
}
free(mem);
if ( ferror(fp) )
{
error_out_errno:
error_fp(err, 0, errno, "%s", fpname);
error_out:
ChangeRulesAmount(rules_at_start);
return false;
}
return true;
}
int compare_path(const void* a_ptr, const void* b_ptr)
{
const char* a = *(const char* const*) a_ptr;
const char* b = *(const char* const*) b_ptr;
return strcmp(a, b);
}
bool InclusionRules::AddManifestPath(const char* path, FILE* err)
{
if ( manifest_used == manifest_length )
{
size_t new_length = 2 * manifest_length;
if ( new_length == 0 )
new_length = 64;
size_t new_size = new_length * sizeof(char*);
char** new_manifest = (char**) realloc(manifest, new_size);
if ( !new_manifest )
{
error_fp(err, 0, errno, "malloc");
return false;
}
manifest = new_manifest;
manifest_length = new_length;
}
char* copy = strdup(path);
if ( !copy )
{
error_fp(err, 0, errno, "malloc");
return false;
}
manifest[manifest_used++] = copy;
return true;
}
bool InclusionRules::AddManifestFromFile(FILE* fp, FILE* err, const char* fpname)
{
char* line = NULL;
size_t line_size = 0;
ssize_t line_len;
while ( 0 <= (line_len = getline(&line, &line_size, fp)) )
{
if ( line_len && line[line_len-1] == '\n' )
line[line_len-1] = '\0';
if ( !AddManifestPath(line, err) )
return false;
}
free(line);
if ( ferror(fp) )
{
error_fp(err, 0, errno, "%s", fpname);
return false;
}
if ( !AddManifestPath("/", err) ||
!AddManifestPath("/tix", err) ||
!AddManifestPath("/tix/manifest", err) )
return false;
char* fpname_copy = strdup(fpname);
if ( !fpname_copy )
{
error_fp(err, 0, errno, "malloc");
return false;
}
const char* fpname_basename = basename(fpname_copy);
char* manifest_path;
if ( asprintf(&manifest_path, "/tix/manifest/%s", fpname_basename) < 0 )
{
free(fpname_copy);
error_fp(err, 0, errno, "malloc");
return false;
}
free(fpname_copy);
if ( !AddManifestPath(manifest_path, err) )
return free(manifest_path), false;
free(manifest_path);
qsort(manifest, manifest_used, sizeof(char*), compare_path);
return true;
}