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#include "common.h"
#include "parse_ini.h"
#include "utils_base.h"
#include <ctype.h>
/* np_ini_info contains the result of parsing a "locator" in the format
* [stanza_name][@config_filename] (check_foo@/etc/foo.ini, for example)
*/
typedef struct {
char *file;
char *stanza;
} np_ini_info;
/* eat all characters from a FILE pointer until n is encountered */
#define GOBBLE_TO(f, c, n) do { (c)=fgetc((f)); } while((c)!=EOF && (c)!=(n))
/* internal function that returns the constructed defaults options */
static char* read_defaults(FILE *f, const char *stanza);
/* internal function that converts a single line into options format */
static int add_option(FILE *f, char **optbuf, size_t *bufsize);
/* parse_locator decomposes a string of the form
* [stanza][@filename]
* into its seperate parts
*/
static void parse_locator(const char *locator, const char *def_stanza, np_ini_info *i){
size_t locator_len, stanza_len;
locator_len=strlen(locator);
stanza_len=strcspn(locator, "@");
/* if a non-default stanza is provided */
if(stanza_len>0){
i->stanza=(char*)malloc(sizeof(char)*(stanza_len+1));
strncpy(i->stanza, locator, stanza_len);
i->stanza[stanza_len]='\0';
} else { /* otherwise we use the default stanza */
i->stanza=strdup(def_stanza);
}
/* if there is no @file part */
if(stanza_len==locator_len){
i->file=strdup(NP_DEFAULT_INI_PATH);
} else {
i->file=strdup(&(locator[stanza_len+1]));
}
if(i->file==NULL || i->stanza==NULL){
die(STATE_UNKNOWN, _("malloc() failed!\n"));
}
}
/* this is the externally visible function used by plugins */
char* np_get_defaults(const char *locator, const char *default_section){
FILE *inifile=NULL;
char *defaults=NULL;
np_ini_info i;
parse_locator(locator, default_section, &i);
/* if a file was specified or if we're using the default file */
if(i.file != NULL && strlen(i.file) > 0){
if(strcmp(i.file, "-")==0){
inifile=stdout;
} else {
inifile=fopen(i.file, "r");
}
if(inifile==NULL) die(STATE_UNKNOWN, _("Config file error"));
defaults=read_defaults(inifile, i.stanza);
free(i.file);
if(inifile!=stdout) fclose(inifile);
}
free(i.stanza);
return defaults;
}
/* read_defaults is where the meat of the parsing takes place.
*
* note that this may be called by a setuid binary, so we need to
* be extra careful about user-supplied input (i.e. avoiding possible
* format string vulnerabilities, etc)
*/
static char* read_defaults(FILE *f, const char *stanza){
int c;
char *opts=NULL;
size_t i, stanza_len, opts_buf_size=0;
enum { NOSTANZA, WRONGSTANZA, RIGHTSTANZA } stanzastate=NOSTANZA;
stanza_len=strlen(stanza);
/* our little stanza-parsing state machine. */
while((c=fgetc(f))!=EOF){
/* gobble up leading whitespace */
if(isspace(c)) continue;
switch(c){
/* globble up coment lines */
case '#':
GOBBLE_TO(f, c, '\n');
break;
/* start of a stanza. check to see if it matches */
case '[':
stanzastate=WRONGSTANZA;
for(i=0; i<stanza_len; i++){
c=fgetc(f);
/* nope, read to the end of the stanza header */
if(c!=stanza[i]) {
GOBBLE_TO(f, c, ']');
break;
}
}
/* if it matched up to here and the next char is ']'... */
if(i==stanza_len){
c=fgetc(f);
if(c==']') stanzastate=RIGHTSTANZA;
}
break;
/* otherwise, we're in the body of a stanza or a parse error */
default:
switch(stanzastate){
/* we never found the start of the first stanza, so
* we're dealing with a config error
*/
case NOSTANZA:
die(STATE_UNKNOWN, _("Config file error"));
break;
/* we're in a stanza, but for a different plugin */
case WRONGSTANZA:
GOBBLE_TO(f, c, '\n');
break;
/* okay, this is where we start taking the config */
case RIGHTSTANZA:
ungetc(c, f);
if(add_option(f, &opts, &opts_buf_size)){
die(STATE_UNKNOWN, _("Config file error"));
}
break;
}
break;
}
}
return opts;
}
/*
* read one line of input in the format
* ^option[[:space:]]*(=[[:space:]]*value)?
* and creates it as a cmdline argument
* --option[=value]
* appending it to the string pointed to by optbuf (which will
* be dynamically grown if needed)
*/
static int add_option(FILE *f, char **optbuf, size_t *bufsize){
char *newbuf=*optbuf;
char *linebuf=NULL, *lineend=NULL, *optptr=NULL, *optend=NULL;
char *eqptr=NULL, *valptr=NULL, *spaceptr=NULL, *valend=NULL;
short done_reading=0, equals=0, value=0;
size_t cfg_len=0, read_sz=8, linebuf_sz=0, read_pos=0, bs=*bufsize;
size_t opt_len=0, val_len=0;
/* read one line from the file */
while(!done_reading){
/* grow if necessary */
if(linebuf==NULL || read_pos+read_sz >= linebuf_sz){
linebuf_sz=(linebuf_sz>0)?linebuf_sz<<1:read_sz;
linebuf=realloc(linebuf, linebuf_sz);
if(linebuf==NULL) die(STATE_UNKNOWN, _("malloc() failed!\n"));
}
if(fgets(&linebuf[read_pos], read_sz, f)==NULL) done_reading=1;
else {
read_pos=strlen(linebuf);
if(linebuf[read_pos-1]=='\n') {
linebuf[--read_pos]='\0';
done_reading=1;
}
}
}
lineend=&linebuf[read_pos];
/* all that to read one line. isn't C fun? :) now comes the parsing :/ */
/* skip leading whitespace */
for(optptr=linebuf; optptr<lineend && isspace(*optptr); optptr++);
/* continue to '=' or EOL, watching for spaces that might precede it */
for(eqptr=optptr; eqptr<lineend && *eqptr!='='; eqptr++){
if(isspace(*eqptr) && optend==NULL) optend=eqptr;
else optend=NULL;
}
if(optend==NULL) optend=eqptr;
--optend;
/* ^[[:space:]]*=foo is a syntax error */
if(optptr==eqptr) die(STATE_UNKNOWN, _("Config file error\n"));
/* continue from '=' to start of value or EOL */
for(valptr=eqptr+1; valptr<lineend && isspace(*valptr); valptr++);
/* continue to the end of value, watching for trailing space/comments */
for(valend=valptr; valend<lineend; valend++){
if(isspace(*valend) && spaceptr==NULL) spaceptr=valend;
else if(*valend=='#') break;
else spaceptr=NULL;
}
if(spaceptr!=NULL) valend=spaceptr;
--valend;
/* calculate the length of "--foo" */
opt_len=1+optend-optptr;
cfg_len=2+(opt_len);
/* if valptr<lineend then we have to also allocate space for "=bar" */
if(valptr<lineend) {
equals=value=1;
val_len=1+valend-valptr;
cfg_len+=1+val_len;
}
/* if valptr==valend then we have "=" but no "bar" */
else if (valptr==lineend) {
equals=1;
cfg_len+=1;
}
/* okay, now we have all the info we need, so we grow the default opts
* buffer if it's necessary, and put everything together.
* (+2 is for a potential space and a null byte)
*/
read_pos=(newbuf==NULL)?0:strlen(newbuf);
if(newbuf==NULL || read_pos+cfg_len+2 >= bs){
bs=(bs>0)?(bs+cfg_len+2)<<1:cfg_len+1;
newbuf=realloc(newbuf, bs);
if(newbuf==NULL) die(STATE_UNKNOWN, _("malloc() failed!\n"));
}
if(read_pos>0) newbuf[read_pos++]=' ';
strncpy(&newbuf[read_pos], "--", 2); read_pos+=2;
strncpy(&newbuf[read_pos], optptr, opt_len); read_pos+=opt_len;
if(equals) newbuf[read_pos++]='=';
if(value) {
strncpy(&newbuf[read_pos], valptr, val_len); read_pos+=val_len;
}
newbuf[read_pos]='\0';
*optbuf=newbuf;
*bufsize=bs;
free(linebuf);
return 0;
}
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