pkg-monitoring-plugins/lib/parse_ini.c

367 lines
11 KiB
C

/*****************************************************************************
*
* Nagios-plugins parse_ini library
*
* License: GPL
* Copyright (c) 2007 Nagios Plugins Development Team
*
* This program 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.
*
* This program 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 this program. If not, see <http://www.gnu.org/licenses/>.
*
*
*****************************************************************************/
#include "common.h"
#include "utils_base.h"
#include "parse_ini.h"
#include <ctype.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
/* TODO: die like N::P if config file is not found */
/* 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 int read_defaults(FILE *f, const char *stanza, np_arg_list **opts);
/* internal function that converts a single line into options format */
static int add_option(FILE *f, np_arg_list **optlst);
/* internal function to find default file */
static char* default_file(void);
/* internal function to stat() files */
static int test_file(const char* env, int len, const char* file, char* temp_file);
/* 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=0, stanza_len=0;
/* if locator is NULL we'll use default values */
if(locator){
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=default_file();
if(strcmp(i->file, "") == 0){
die(STATE_UNKNOWN, _("Cannot find '%s' or '%s' in any standard location.\n"), NP_DEFAULT_INI_FILENAME1, NP_DEFAULT_INI_FILENAME2);
}
} 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 extra_opts */
np_arg_list* np_get_defaults(const char *locator, const char *default_section){
FILE *inifile=NULL;
np_arg_list *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=stdin;
} else {
inifile=fopen(i.file, "r");
}
if(inifile==NULL) die(STATE_UNKNOWN, _("Can't read config file"));
if(read_defaults(inifile, i.stanza, &defaults)==FALSE)
die(STATE_UNKNOWN, _("Invalid section '%s' in config file '%s'\n"), i.stanza, i.file);
free(i.file);
if(inifile!=stdin) 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 int read_defaults(FILE *f, const char *stanza, np_arg_list **opts){
int c, status=FALSE;
size_t i, stanza_len;
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 ';':
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);
/* Strip leading whitespace */
if(i==0) for(c; isspace(c); c=fgetc(f));
/* nope, read to the end of the line */
if(c!=stanza[i]) {
GOBBLE_TO(f, c, '\n');
break;
}
}
/* if it matched up to here and the next char is ']'... */
if(i==stanza_len){
c=fgetc(f);
/* Strip trailing whitespace */
for(c; isspace(c); 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)){
die(STATE_UNKNOWN, _("Config file error"));
}
status=TRUE;
break;
}
break;
}
}
return status;
}
/*
* 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 linked list optbuf.
*/
static int add_option(FILE *f, np_arg_list **optlst){
np_arg_list *opttmp=*optlst, *optnew;
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;
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 */
for(valend=valptr; valend<lineend; valend++);
--valend;
/* Finally trim off trailing spaces */
for(valend; isspace(*valend); valend--);
/* calculate the length of "--foo" */
opt_len=1+optend-optptr;
/* 1-character params needs only one dash */
if(opt_len==1)
cfg_len=1+(opt_len);
else
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;
}
/* A line with no equal sign isn't valid */
if(equals==0) die(STATE_UNKNOWN, _("Config file error\n"));
/* okay, now we have all the info we need, so we create a new np_arg_list
* element and set the argument...
*/
optnew=(np_arg_list *)malloc(sizeof(np_arg_list));
optnew->next=NULL;
read_pos=0;
optnew->arg=(char *)malloc(cfg_len+1);
/* 1-character params needs only one dash */
if(opt_len==1) {
strncpy(&optnew->arg[read_pos], "-", 1);
read_pos+=1;
} else {
strncpy(&optnew->arg[read_pos], "--", 2);
read_pos+=2;
}
strncpy(&optnew->arg[read_pos], optptr, opt_len); read_pos+=opt_len;
if(value) {
optnew->arg[read_pos++]='=';
strncpy(&optnew->arg[read_pos], valptr, val_len); read_pos+=val_len;
}
optnew->arg[read_pos]='\0';
/* ...and put that to the end of the list */
if(*optlst==NULL) {
*optlst=optnew;
} else {
while(opttmp->next!=NULL) {
opttmp=opttmp->next;
}
opttmp->next = optnew;
}
free(linebuf);
return 0;
}
static char* default_file(void){
struct stat sb;
char *np_env=NULL, *default_file=NULL;
char temp_file[MAX_INPUT_BUFFER];
size_t len;
if((np_env=getenv("NAGIOS_CONFIG_PATH"))!=NULL) {
/* skip any starting colon... */
while(*np_env==':') np_env++;
/* Look for NP_DEFAULT_INI_FILENAME1 and NP_DEFAULT_INI_FILENAME2 in
* every PATHs defined (colon-separated).
*/
while((len=strcspn(np_env,":"))>0){
/* Test NP_DEFAULT_INI_FILENAME[1-2] in current np_env token */
if(test_file(np_env,len,NP_DEFAULT_INI_FILENAME1,temp_file)==1 ||
test_file(np_env,len,NP_DEFAULT_INI_FILENAME2,temp_file)==1){
default_file=strdup(temp_file);
break;
}
/* Move on to the next token */
np_env+=len;
while(*np_env==':') np_env++;
} /* while(...) */
} /* if(getenv("NAGIOS_CONFIG_PATH")) */
/* Look for NP_DEFAULT_INI_FILENAME1 in NP_DEFAULT_INI_NAGIOS_PATH[1-4] */
if(!default_file){
if(test_file(NP_DEFAULT_INI_NAGIOS_PATH1,strlen(NP_DEFAULT_INI_NAGIOS_PATH1),NP_DEFAULT_INI_FILENAME1,temp_file)==1 ||
test_file(NP_DEFAULT_INI_NAGIOS_PATH2,strlen(NP_DEFAULT_INI_NAGIOS_PATH2),NP_DEFAULT_INI_FILENAME1,temp_file)==1 ||
test_file(NP_DEFAULT_INI_NAGIOS_PATH3,strlen(NP_DEFAULT_INI_NAGIOS_PATH3),NP_DEFAULT_INI_FILENAME1,temp_file)==1 ||
test_file(NP_DEFAULT_INI_NAGIOS_PATH4,strlen(NP_DEFAULT_INI_NAGIOS_PATH4),NP_DEFAULT_INI_FILENAME1,temp_file)==1)
default_file=strdup(temp_file);
}
/* Look for NP_DEFAULT_INI_FILENAME2 in NP_DEFAULT_INI_PATH[1-3] */
if(!default_file){
if(test_file(NP_DEFAULT_INI_PATH1,strlen(NP_DEFAULT_INI_PATH1),NP_DEFAULT_INI_FILENAME2,temp_file)==1 ||
test_file(NP_DEFAULT_INI_PATH2,strlen(NP_DEFAULT_INI_PATH2),NP_DEFAULT_INI_FILENAME2,temp_file)==1 ||
test_file(NP_DEFAULT_INI_PATH3,strlen(NP_DEFAULT_INI_PATH3),NP_DEFAULT_INI_FILENAME2,temp_file)==1)
default_file=strdup(temp_file);
}
/* Return default_file or empty string (should return NULL if we want plugins
* to die there)...
*/
if(default_file)
return default_file;
return "";
}
/* put together len bytes from env and the filename and test for its
* existence. Returns 1 if found, 0 if not and -1 if test wasn't performed.
*/
static int test_file(const char* env, int len, const char* file, char* temp_file){
struct stat sb;
/* test if len + filelen + '/' + '\0' fits in temp_file */
if((len+strlen(file)+2)>MAX_INPUT_BUFFER) return -1;
strncpy(temp_file,env,len);
temp_file[len]='\0';
strncat(temp_file,"/",len+1);
strncat(temp_file,file,len+strlen(file)+1);
if(stat(temp_file, &sb) != -1) return 1;
return 0;
}