#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; }