unbound/sldns/parse.c

524 lines
11 KiB
C

/*
* a generic (simple) parser. Use to parse rr's, private key
* information and /etc/resolv.conf files
*
* a Net::DNS like library for C
* LibDNS Team @ NLnet Labs
* (c) NLnet Labs, 2005-2006
* See the file LICENSE for the license
*/
#include "config.h"
#include "sldns/parse.h"
#include "sldns/parseutil.h"
#include "sldns/sbuffer.h"
#include <limits.h>
#include <strings.h>
sldns_lookup_table sldns_directive_types[] = {
{ LDNS_DIR_TTL, "$TTL" },
{ LDNS_DIR_ORIGIN, "$ORIGIN" },
{ LDNS_DIR_INCLUDE, "$INCLUDE" },
{ 0, NULL }
};
/* add max_limit here? */
ssize_t
sldns_fget_token(FILE *f, char *token, const char *delim, size_t limit)
{
return sldns_fget_token_l(f, token, delim, limit, NULL);
}
ssize_t
sldns_fget_token_l(FILE *f, char *token, const char *delim, size_t limit, int *line_nr)
{
int c, prev_c;
int p; /* 0 -> no parentheses seen, >0 nr of ( seen */
int com, quoted, only_blank;
char *t;
size_t i;
const char *d;
const char *del;
/* standard delimiters */
if (!delim) {
/* from isspace(3) */
del = LDNS_PARSE_NORMAL;
} else {
del = delim;
}
p = 0;
i = 0;
com = 0;
quoted = 0;
prev_c = 0;
only_blank = 1; /* Assume we got only <blank> until now */
t = token;
if (del[0] == '"') {
quoted = 1;
}
while ((c = getc(f)) != EOF) {
if (c == '\r') /* carriage return */
c = ' ';
if (c == '(' && prev_c != '\\' && !quoted) {
/* this only counts for non-comments */
if (com == 0) {
p++;
}
prev_c = c;
continue;
}
if (c == ')' && prev_c != '\\' && !quoted) {
/* this only counts for non-comments */
if (com == 0) {
p--;
}
prev_c = c;
continue;
}
if (p < 0) {
/* more ) then ( - close off the string */
*t = '\0';
return 0;
}
/* do something with comments ; */
if (c == ';' && quoted == 0) {
if (prev_c != '\\') {
com = 1;
}
}
if (c == '\"' && com == 0 && prev_c != '\\') {
quoted = 1 - quoted;
}
if (c == '\n' && com != 0) {
/* comments */
com = 0;
*t = ' ';
if (line_nr) {
*line_nr = *line_nr + 1;
}
if (only_blank && i > 0) {
/* Got only <blank> so far. Reset and try
* again with the next line.
*/
i = 0;
t = token;
}
if (p == 0) {
/* If p != 0 then the next line is a continuation. So
* we assume that the next line starts with a blank only
* if it is actually a new line.
*/
only_blank = 1; /* Assume next line starts with
* <blank>.
*/
}
if (p == 0 && i > 0) {
goto tokenread;
} else {
prev_c = c;
continue;
}
}
if (com == 1) {
*t = ' ';
prev_c = c;
continue;
}
if (c == '\n' && p != 0 && t > token) {
/* in parentheses */
if (line_nr) {
*line_nr = *line_nr + 1;
}
if (limit > 0 && (i+1 >= limit || (size_t)(t-token)+1 >= limit)) {
*t = '\0';
return -1;
}
*t++ = ' ';
prev_c = c;
continue;
}
/* check if we hit the delim */
for (d = del; *d; d++) {
if (c == *d)
break;
}
if (c == *d && i > 0 && prev_c != '\\' && p == 0) {
if (c == '\n' && line_nr) {
*line_nr = *line_nr + 1;
}
if (only_blank) {
/* Got only <blank> so far. Reset and
* try again with the next line.
*/
i = 0;
t = token;
only_blank = 1;
prev_c = c;
continue;
}
goto tokenread;
}
if (c != ' ' && c != '\t') {
/* Found something that is not <blank> */
only_blank= 0;
}
if (c != '\0' && c != '\n') {
i++;
}
/* is there space for the character and the zero after it */
if (limit > 0 && (i+1 >= limit || (size_t)(t-token)+1 >= limit)) {
*t = '\0';
return -1;
}
if (c != '\0' && c != '\n') {
*t++ = c;
}
if (c == '\n') {
if (line_nr) {
*line_nr = *line_nr + 1;
}
only_blank = 1; /* Assume next line starts with
* <blank>.
*/
}
if (c == '\\' && prev_c == '\\')
prev_c = 0;
else prev_c = c;
}
*t = '\0';
if (c == EOF) {
return (ssize_t)i;
}
if (i == 0) {
/* nothing read */
return -1;
}
if (p != 0) {
return -1;
}
return (ssize_t)i;
tokenread:
if(*del == '"')
/* do not skip over quotes after the string, they are part
* of the next string. But skip over whitespace (if needed)*/
sldns_fskipcs_l(f, del+1, line_nr);
else sldns_fskipcs_l(f, del, line_nr);
*t = '\0';
if (p != 0) {
return -1;
}
return (ssize_t)i;
}
ssize_t
sldns_fget_keyword_data(FILE *f, const char *keyword, const char *k_del, char *data,
const char *d_del, size_t data_limit)
{
return sldns_fget_keyword_data_l(f, keyword, k_del, data, d_del,
data_limit, NULL);
}
ssize_t
sldns_fget_keyword_data_l(FILE *f, const char *keyword, const char *k_del, char *data,
const char *d_del, size_t data_limit, int *line_nr)
{
/* we assume: keyword|sep|data */
char *fkeyword;
ssize_t i;
if(strlen(keyword) >= LDNS_MAX_KEYWORDLEN)
return -1;
fkeyword = (char*)malloc(LDNS_MAX_KEYWORDLEN);
if(!fkeyword)
return -1;
i = sldns_fget_token(f, fkeyword, k_del, LDNS_MAX_KEYWORDLEN);
if(i==0 || i==-1) {
free(fkeyword);
return -1;
}
/* case??? i instead of strlen? */
if (strncmp(fkeyword, keyword, LDNS_MAX_KEYWORDLEN - 1) == 0) {
/* whee! */
/* printf("%s\n%s\n", "Matching keyword", fkeyword); */
i = sldns_fget_token_l(f, data, d_del, data_limit, line_nr);
free(fkeyword);
return i;
} else {
/*printf("no match for %s (read: %s)\n", keyword, fkeyword);*/
free(fkeyword);
return -1;
}
}
int
sldns_bgetc(sldns_buffer *buffer)
{
if (!sldns_buffer_available_at(buffer, buffer->_position, sizeof(uint8_t))) {
sldns_buffer_set_position(buffer, sldns_buffer_limit(buffer));
/* sldns_buffer_rewind(buffer);*/
return EOF;
}
return (int)sldns_buffer_read_u8(buffer);
}
ssize_t
sldns_bget_token(sldns_buffer *b, char *token, const char *delim, size_t limit)
{
return sldns_bget_token_par(b, token, delim, limit, NULL, NULL);
}
ssize_t
sldns_bget_token_par(sldns_buffer *b, char *token, const char *delim,
size_t limit, int* par, const char* skipw)
{
int c, lc;
int p; /* 0 -> no parentheses seen, >0 nr of ( seen */
int com, quoted;
char *t;
size_t i;
const char *d;
const char *del;
/* standard delimiters */
if (!delim) {
/* from isspace(3) */
del = LDNS_PARSE_NORMAL;
} else {
del = delim;
}
p = (par?*par:0);
i = 0;
com = 0;
quoted = 0;
t = token;
lc = 0;
if (del[0] == '"') {
quoted = 1;
}
while ((c = sldns_bgetc(b)) != EOF) {
if (c == '\r') /* carriage return */
c = ' ';
if (c == '(' && lc != '\\' && !quoted) {
/* this only counts for non-comments */
if (com == 0) {
if(par) (*par)++;
p++;
}
lc = c;
continue;
}
if (c == ')' && lc != '\\' && !quoted) {
/* this only counts for non-comments */
if (com == 0) {
if(par) (*par)--;
p--;
}
lc = c;
continue;
}
if (p < 0) {
/* more ) then ( */
*t = '\0';
return 0;
}
/* do something with comments ; */
if (c == ';' && quoted == 0) {
if (lc != '\\') {
com = 1;
}
}
if (c == '"' && com == 0 && lc != '\\') {
quoted = 1 - quoted;
}
if (c == '\n' && com != 0) {
/* comments */
com = 0;
*t = ' ';
lc = c;
continue;
}
if (com == 1) {
*t = ' ';
lc = c;
continue;
}
if (c == '\n' && p != 0) {
/* in parentheses */
/* do not write ' ' if we want to skip spaces */
if(!(skipw && (strchr(skipw, c)||strchr(skipw, ' ')))) {
/* check for space for the space character and a zero delimiter after that. */
if (limit > 0 && (i+1 >= limit || (size_t)(t-token)+1 >= limit)) {
*t = '\0';
return -1;
}
*t++ = ' ';
}
lc = c;
continue;
}
/* check to skip whitespace at start, but also after ( */
if(skipw && i==0 && !com && !quoted && lc != '\\') {
if(strchr(skipw, c)) {
lc = c;
continue;
}
}
/* check if we hit the delim */
for (d = del; *d; d++) {
/* we can only exit if no parens or user tracks them */
if (c == *d && lc != '\\' && (p == 0 || par)) {
goto tokenread;
}
}
i++;
if (limit > 0 && (i+1 >= limit || (size_t)(t-token)+1 >= limit)) {
*t = '\0';
return -1;
}
*t++ = c;
if (c == '\\' && lc == '\\') {
lc = 0;
} else {
lc = c;
}
}
*t = '\0';
if (i == 0) {
/* nothing read */
return -1;
}
if (!par && p != 0) {
return -1;
}
return (ssize_t)i;
tokenread:
if(*del == '"')
/* do not skip over quotes after the string, they are part
* of the next string. But skip over whitespace (if needed)*/
sldns_bskipcs(b, del+1);
else sldns_bskipcs(b, del);
*t = '\0';
if (!par && p != 0) {
return -1;
}
return (ssize_t)i;
}
void
sldns_bskipcs(sldns_buffer *buffer, const char *s)
{
int found;
char c;
const char *d;
while(sldns_buffer_available_at(buffer, buffer->_position, sizeof(char))) {
c = (char) sldns_buffer_read_u8_at(buffer, buffer->_position);
found = 0;
for (d = s; *d; d++) {
if (*d == c) {
found = 1;
}
}
if (found && buffer->_limit > buffer->_position) {
buffer->_position += sizeof(char);
} else {
return;
}
}
}
void
sldns_fskipcs(FILE *fp, const char *s)
{
sldns_fskipcs_l(fp, s, NULL);
}
void
sldns_fskipcs_l(FILE *fp, const char *s, int *line_nr)
{
int found;
int c;
const char *d;
while ((c = fgetc(fp)) != EOF) {
if (line_nr && c == '\n') {
*line_nr = *line_nr + 1;
}
found = 0;
for (d = s; *d; d++) {
if (*d == c) {
found = 1;
}
}
if (!found) {
/* with getc, we've read too far */
ungetc(c, fp);
return;
}
}
}
ssize_t
sldns_bget_keyword_data(sldns_buffer *b, const char *keyword, const char *k_del, char
*data, const char *d_del, size_t data_limit)
{
/* we assume: keyword|sep|data */
char *fkeyword;
ssize_t i;
if(strlen(keyword) >= LDNS_MAX_KEYWORDLEN)
return -1;
fkeyword = (char*)malloc(LDNS_MAX_KEYWORDLEN);
if(!fkeyword)
return -1; /* out of memory */
i = sldns_bget_token(b, fkeyword, k_del, data_limit);
if(i==0 || i==-1) {
free(fkeyword);
return -1; /* nothing read */
}
/* case??? */
if (strncmp(fkeyword, keyword, strlen(keyword)) == 0) {
free(fkeyword);
/* whee, the match! */
/* retrieve it's data */
i = sldns_bget_token(b, data, d_del, 0);
return i;
} else {
free(fkeyword);
return -1;
}
}