lexer.l

   1 /*
   2  * userv is copyright Ian Jackson and other contributors.
   3  * See README for full authorship information.
   4  *
   5  * This is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 3 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with userv; if not, see <http://www.gnu.org/licenses/>.
  17  */
  18
  19 %{
  20
  21
  22
  23
  24
  25 #include <syslog.h>
  26 #include <assert.h>
  27 #include <stdio.h>
  28 #include <stdarg.h>
  29 #include <ctype.h>
  30 #include <string.h>
  31 #include <unistd.h>
  32 #include <pwd.h>
  33 #include <grp.h>
  34 #include <fnmatch.h>
  35 #include <limits.h>
  36 #include <dirent.h>
  37 #include <sys/types.h>
  38 #include <sys/stat.h>
  39 #include <time.h>
  40 #include <errno.h>
  41
  42 #include "config.h"
  43 #include "common.h"
  44 #include "daemon.h"
  45 #include "lib.h"
  46 #include "both.h"
  47 #include "tokens.h"
  48
  49 #define HYPHEN '-'
  50
  51 typedef int directive_fnt(int dtoken);
  52 static directive_fnt df_reject, df_execute, df_executefrompath;
  53 static directive_fnt df_executefromdirectory, df_executebuiltin;
  54 static directive_fnt df_errorstostderr, df_errorstosyslog, df_errorstofile;
  55 static directive_fnt dfg_fdwant, dfg_setflag, dfg_lookupquotemode;
  56 static directive_fnt df_reset, df_cd, df_userrcfile, df_include;
  57 static directive_fnt df_includelookup, df_includedirectory;
  58 static directive_fnt df_message, df_error, df_quit, df_eof;
  59 static directive_fnt df_if, df_catchquit, df_errorspush;
  60 static directive_fnt dfi_includeuserrcfile, dfi_includeclientconfig;
  61 /* directive functions return:
  62  *  0 for success having scanned up to and including end of line but not beyond,
  63  *  or tokv_error or tokv_quit.
  64  * They expect to parse the whitespace before their parameters (if any).
  65  */
  66
  67 typedef int parmcondition_fnt(int ctoken, char *const *parmvalues, int *rtrue);
  68 static parmcondition_fnt pcf_glob, pcf_range, pcf_grep;
  69 /* all conditional functions return tokv_error for failure or 0 for success
  70  *  at parsing and testing, in which case *rtrue is set to 0 or 1.
  71  *  On success they have scanned up to and including the condition's
  72  *  terminating newline; the pcf_... functions expect to parse the whitespace
  73  *  between the parameter name and the condition's arguments.
  74  * Otherwise they return tokv_error.
  75  * The parameter-based conditionals take a list of parameter values
  76  * as obtained from the parameter functions and pa_parameter,
  77  * and do _not_ free it.
  78  */
  79
  80 typedef int parameter_fnt(int ptoken, char ***rvalues);
  81 static parameter_fnt pf_service;
  82 static parameter_fnt pf_callinguser, pf_serviceuser;
  83 static parameter_fnt pf_callinggroup, pf_servicegroup;
  84 static parameter_fnt pf_callingusershell, pf_serviceusershell;
  85 /* Parameter functions return tokv_error or 0 for success at parsing
  86  * and determining the value, in which case *rvalues is made to be
  87  * a mallocd null-terminated array of pointers to mallocd strings.
  88  * freeparm can be used to free such an array.
  89  */
  90
  91 typedef int builtinserviceparse_fnt(char ***rnewargs);
  92 static builtinserviceparse_fnt bispa_none, bispa_parameter;
  93 /* These parse the arguments to a builtin service, including the
  94  * newline at the end of the line.  *rnewargs will initially be
  95  * null, indicating that no arguments are to be set; the function
  96  * may store a mallocd array of mallocd strings in it,
  97  * containing the arguments it wishes to have set (null-pointer
  98  * terminated).
  99  */
 100
 101 static int yylex(void);
 102 /* Returns a token (which may be an eof or error exception) */
 103
 104 static directive_fnt *lr_dir;
 105 static parmcondition_fnt *lr_parmcond;
 106 static builtinserviceparse_fnt *lr_bispa;
 107 static builtinserviceexec_fnt *lr_bisexec;
 108 static parameter_fnt *lr_parameter;
 109 static int lr_loglevel, lr_logfacility, lr_min, lr_max, *lr_flag;
 110 static int lr_flagval, lr_controlend;
 111 static int lr_fdwant_readwrite; /* -1=never, 0=opt, 1=always */
 112
 113 /* Forward declarations of things used in lexer and parser */
 114
 115 struct parser_state {
 116   int lineno, reportlineno, notedreferer, isinternal;
 117   const char *filename;
 118   struct stat filestab;
 119   YY_BUFFER_STATE ybuf;
 120   struct parser_state *upstate;
 121 };
 122
 123 static struct parser_state *cstate;
 124
 125 struct error_handling {
 126   int handling; /* One of the error handling modes tokt_ehandlemode */
 127   int logfacility, loglevel;
 128   int filekeep; /* File is in use by higher-level errors-push, leave it open */
 129   FILE *file;
 130   char *filename;
 131 };
 132
 133 static struct error_handling eh = { tokv_word_errorstostderr, 0,0,0,0,0 };
 134
 135 static int dequote(char *inplace);
 136 static void countnewlines(void);
 137
 138 #define YY_NO_INPUT
 139
 140 %}
 141
 142 %option noyywrap
 143 %option nounput
 144
 145 %%
 146
 147 reject { lr_dir= df_reject; return tokv_word_reject; }
 148 execute-from-directory { lr_dir= df_executefromdirectory; return tokv_word_executefromdirectory; }
 149 execute-from-path { lr_dir= df_executefrompath; return tokv_word_executefrompath; }
 150 execute-builtin { lr_dir= df_executebuiltin; return tokv_word_executebuiltin; }
 151 errors-to-stderr { lr_dir= df_errorstostderr; return tokv_word_errorstostderr; }
 152 errors-to-syslog { lr_dir= df_errorstosyslog; return tokv_word_errorstosyslog; }
 153 errors-to-file { lr_dir= df_errorstofile; return tokv_word_errorstofile; }
 154 include-lookup-quote-old { lr_dir= dfg_lookupquotemode; return tokv_word_includelookupquoteold; }
 155 include-lookup-quote-new { lr_dir= dfg_lookupquotemode; return tokv_word_includelookupquotenew; }
 156 require-fd { lr_dir= dfg_fdwant; lr_fdwant_readwrite=1; return tokv_word_requirefd; }
 157 allow-fd { lr_dir= dfg_fdwant; lr_fdwant_readwrite=0; return tokv_word_allowfd; }
 158 null-fd { lr_dir= dfg_fdwant; lr_fdwant_readwrite=0; return tokv_word_nullfd; }
 159 reject-fd { lr_dir= dfg_fdwant; lr_fdwant_readwrite=-1; return tokv_word_rejectfd; }
 160 ignore-fd { lr_dir= dfg_fdwant; lr_fdwant_readwrite=-1; return tokv_word_ignorefd; }
 161 set-environment { lr_dir= dfg_setflag; lr_flag= &setenvironment; lr_flagval= 1; return tokv_word_setenvironment; }
 162 no-set-environment { lr_dir= dfg_setflag; lr_flag= &setenvironment; lr_flagval= 0; return tokv_word_nosetenvironment; }
 163 suppress-args { lr_dir= dfg_setflag; lr_flag= &suppressargs; lr_flagval= 1; return tokv_word_suppressargs; }
 164 no-suppress-args { lr_dir= dfg_setflag; lr_flag= &suppressargs; lr_flagval= 0; return tokv_word_nosuppressargs; }
 165 disconnect-hup { lr_dir= dfg_setflag; lr_flag= &disconnecthup; lr_flagval= 1; return tokv_word_disconnecthup; }
 166 no-disconnect-hup { lr_dir= dfg_setflag; lr_flag= &disconnecthup; lr_flagval= 0; return tokv_word_nodisconnecthup; }
 167 cd { lr_dir= df_cd; return tokv_word_cd; }
 168 user-rcfile { lr_dir= df_userrcfile; return tokv_word_userrcfile; }
 169 include { lr_dir= df_include; return tokv_word_include; }
 170 include-ifexist { lr_dir= df_include; return tokv_word_includeifexist; }
 171 include-lookup { lr_dir= df_includelookup; return tokv_word_includelookup; }
 172 include-lookup-all { lr_dir= df_includelookup; return tokv_word_includelookupall; }
 173 include-directory { lr_dir= df_includedirectory; return tokv_word_includedirectory; }
 174 message { lr_dir= df_message; return tokv_word_message; }
 175 _include-sysconfig { lr_dir= df_include; return tokv_word_includesysconfig; }
 176 _include-user-rcfile { lr_dir= dfi_includeuserrcfile; return tokv_word_includeuserrcfile; }
 177 _include-client-config { lr_dir= dfi_includeclientconfig; return tokv_word_includeclientconfig; }
 178 quit { lr_dir= df_quit; return tokv_word_quit; }
 179 eof { lr_dir= df_eof; return tokv_word_eof; }
 180 if { lr_dir= df_if; return tokv_word_if; }
 181 catch-quit { lr_dir= df_catchquit; return tokv_word_catchquit; }
 182 errors-push { lr_dir= df_errorspush; return tokv_word_errorspush; }
 183 elif { lr_controlend= tokv_word_if; return tokv_word_elif; }
 184 else { lr_controlend= tokv_word_if; return tokv_word_else; }
 185 fi { lr_controlend= tokv_word_if; return tokv_word_fi; }
 186 hctac { lr_controlend= tokv_word_catchquit; return tokv_word_hctac; }
 187 srorre { lr_controlend= tokv_word_errorspush; return tokv_word_srorre; }
 188 glob { lr_parmcond= pcf_glob; return tokv_word_glob; }
 189 range { lr_parmcond= pcf_range; return tokv_word_range; }
 190 grep { lr_parmcond= pcf_grep; return tokv_word_grep; }
 191 environment { lr_bispa= bispa_none; lr_bisexec= bisexec_environment; return tokv_word_environment; }
 192 parameter { lr_bispa= bispa_parameter; lr_bisexec= bisexec_parameter; return tokv_word_parameter; }
 193 version { lr_bispa= bispa_none; lr_bisexec= bisexec_version; return tokv_word_version; }
 194 toplevel { lr_bispa= bispa_none; lr_bisexec= bisexec_toplevel; return tokv_word_toplevel; }
 195 override { lr_bispa= bispa_none; lr_bisexec= bisexec_override; return tokv_word_override; }
 196 shutdown { lr_bispa= bispa_none; lr_bisexec= bisexec_shutdown; return tokv_word_shutdown; }
 197 reset { lr_bispa= bispa_none; lr_bisexec= bisexec_reset; lr_dir= df_reset; return tokv_word_reset; }
 198 execute { lr_bispa= bispa_none; lr_bisexec= bisexec_execute; lr_dir= df_execute; return tokv_word_execute; }
 199 help { lr_bispa= bispa_none; lr_bisexec= bisexec_help; return tokv_word_help; }
 200 service { lr_parameter= pf_service; return tokv_word_service; }
 201 calling-user { lr_parameter= pf_callinguser; return tokv_word_callinguser; }
 202 calling-group { lr_parameter= pf_callinggroup; return tokv_word_callinggroup; }
 203 calling-user-shell { lr_parameter= pf_callingusershell; return tokv_word_callingusershell; }
 204 service-user { lr_parameter= pf_serviceuser; return tokv_word_serviceuser; }
 205 service-group { lr_parameter= pf_servicegroup; return tokv_word_servicegroup; }
 206 service-user-shell { lr_parameter= pf_serviceusershell; return tokv_word_serviceusershell; }
 207 debug { lr_loglevel= LOG_DEBUG; return tokv_syslog_debug; }
 208 info { lr_loglevel= LOG_INFO; return tokv_syslog_info; }
 209 notice { lr_loglevel= LOG_NOTICE; return tokv_syslog_notice; }
 210 warn(ing)? { lr_loglevel= LOG_WARNING; return tokv_syslog_warning; }
 211 err { lr_loglevel= LOG_ERR; return tokv_syslog_err; }
 212 crit { lr_loglevel= LOG_CRIT; return tokv_syslog_crit; }
 213 alert { lr_loglevel= LOG_ALERT; return tokv_syslog_alert; }
 214 emerg|panic { lr_loglevel= LOG_EMERG; return tokv_syslog_emerg; }
 215 auth(priv)?|security { lr_logfacility= LOG_AUTHPRIV; return tokv_syslog_authpriv; }
 216 cron { lr_logfacility= LOG_CRON; return tokv_syslog_cron; }
 217 daemon { lr_logfacility= LOG_DAEMON; return tokv_syslog_daemon; }
 218 kern(el)? { lr_logfacility= LOG_KERN; return tokv_syslog_kern; }
 219 lpr { lr_logfacility= LOG_LPR; return tokv_syslog_lpr; }
 220 mail { lr_logfacility= LOG_MAIL; return tokv_syslog_mail; }
 221 news { lr_logfacility= LOG_NEWS; return tokv_syslog_news; }
 222 syslog { lr_logfacility= LOG_SYSLOG; return tokv_syslog_syslog; }
 223 user { lr_logfacility= LOG_USER; return tokv_syslog_user; }
 224 uucp { lr_logfacility= LOG_UUCP; return tokv_syslog_uucp; }
 225 local0 { lr_logfacility= LOG_LOCAL0; return tokv_syslog_local0; }
 226 local1 { lr_logfacility= LOG_LOCAL1; return tokv_syslog_local1; }
 227 local2 { lr_logfacility= LOG_LOCAL2; return tokv_syslog_local2; }
 228 local3 { lr_logfacility= LOG_LOCAL3; return tokv_syslog_local3; }
 229 local4 { lr_logfacility= LOG_LOCAL4; return tokv_syslog_local4; }
 230 local5 { lr_logfacility= LOG_LOCAL5; return tokv_syslog_local5; }
 231 local6 { lr_logfacility= LOG_LOCAL6; return tokv_syslog_local6; }
 232 local7 { lr_logfacility= LOG_LOCAL7; return tokv_syslog_local7; }
 233 read { return tokv_word_read; }
 234 write { return tokv_word_write; }
 235 \$ { return tokv_dollar; }
 236 stdin {  lr_max= lr_min= 0; return tokv_word_stdin; }
 237 stdout {  lr_max= lr_min= 1; return tokv_word_stdout; }
 238 stderr {  lr_max= lr_min= 2; return tokv_word_stderr; }
 239 \( { return tokv_openparen; }
 240 \) { return tokv_closeparen; }
 241 \! { return tokv_not; }
 242 \& { return tokv_and; }
 243 \| { return tokv_or; }
 244 error { lr_dir= df_error; lr_loglevel= LOG_ERR; return tokv_word_error; }
 245
 246
 247
 248 [0-9]{1,8}              {
 249                           char *ep;
 250                           lr_min=lr_max= (int)strtoul(yytext,&ep,10);
 251                           assert(!*ep);
 252                           return tokv_ordinal;
 253                         }
 254 [0-9]{1,8}-[0-9]{1,8}   {
 255                           char *ep;
 256                           lr_min= (int)strtoul(yytext,&ep,10);
 257                           assert(*ep == HYPHEN);
 258                           ep++;  assert(*ep);
 259                           lr_max= (int)strtoul(ep,&ep,10);
 260                           assert(!*ep);
 261                           if (lr_max < lr_min)
 262                             return parseerrprint("fd range has min > max");
 263                           return tokv_fdrange;
 264                         }
 265 [0-9]{1,8}-             {
 266                           char *ep;
 267                           lr_min= (int)strtoul(yytext,&ep,10);
 268                           assert(*ep == HYPHEN);
 269                           ep++;  assert(!*ep);
 270                           lr_max=-1;
 271                           return tokv_fdstoend;
 272                         }
 273 ([\ \t]*\\[\ \t]*\n[\ \t]*)+    countnewlines(); return tokv_lwsp;
 274 [\ \t]+                         return tokv_lwsp;
 275 [\ \t]*\n               cstate->lineno++; return tokv_newline;
 276 [\ \t]*\#[^\n]*\n       cstate->lineno++; return tokv_newline;
 277 [\ \t]*\#[^\n]*         return parseerrprint("missing newline at eof after comment");
 278 \"([^\\\"\n]|\\[a-z]|\\[0-9]{3}|\\x[0-9A-Fa-f]{2}|\\[[:punct:]]|\\[ \t]*\n)*\" {
 279                           countnewlines();
 280                           return dequote(yytext);
 281                         }
 282 [^\ \t\n\\\"]+          return tokv_barestring;
 283 <<EOF>>                 return tokv_eof;
 284 \"                      return parseerrprint("misquoted or unterminated string");
 285 \\                      return parseerrprint("unexpected backslash");
 286 .                       abort(); /* expect lex warning "rule cannot be matched" */
 287
 288
 289 %%
 290
 291 const char *const builtinservicehelpstrings[]= {
 292   "environment",
 293   "parameter <parameter>",
 294   "version",
 295   "toplevel",
 296   "override",
 297   "shutdown",
 298   "reset",
 299   "execute",
 300   "help",
 301    0
 302 };
 303
 304 #include "parser.c"
 305