lexer.l

   1 /* userv is
   2  * Copyright 1996-2017 Ian Jackson <ian@davenant.greenend.org.uk>.
   3  * Copyright 2000      Ben Harris <bjh21@cam.ac.uk>
   4  * Copyright 2016-2017 Peter Benie <pjb1008@cam.ac.uk>
   5  *
   6  * This is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 3 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful, but
  12  * WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with userv; if not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 %{
  21
  22
  23
  24
  25
  26 #include <syslog.h>
  27 #include <assert.h>
  28 #include <stdio.h>
  29 #include <stdarg.h>
  30 #include <ctype.h>
  31 #include <string.h>
  32 #include <unistd.h>
  33 #include <pwd.h>
  34 #include <grp.h>
  35 #include <fnmatch.h>
  36 #include <limits.h>
  37 #include <dirent.h>
  38 #include <sys/types.h>
  39 #include <sys/stat.h>
  40 #include <time.h>
  41 #include <errno.h>
  42
  43 #include "config.h"
  44 #include "common.h"
  45 #include "daemon.h"
  46 #include "lib.h"
  47 #include "both.h"
  48 #include "tokens.h"
  49
  50 #define HYPHEN '-'
  51
  52 typedef int directive_fnt(int dtoken);
  53 static directive_fnt df_reject, df_execute, df_executefrompath;
  54 static directive_fnt df_executefromdirectory, df_executebuiltin;
  55 static directive_fnt df_errorstostderr, df_errorstosyslog, df_errorstofile;
  56 static directive_fnt dfg_fdwant, dfg_setflag, dfg_lookupquotemode;
  57 static directive_fnt df_reset, df_cd, df_userrcfile, df_include;
  58 static directive_fnt df_includelookup, df_includedirectory;
  59 static directive_fnt df_message, df_error, df_quit, df_eof;
  60 static directive_fnt df_if, df_catchquit, df_errorspush;
  61 static directive_fnt dfi_includeuserrcfile, dfi_includeclientconfig;
  62 /* directive functions return:
  63  *  0 for success having scanned up to and including end of line but not beyond,
  64  *  or tokv_error or tokv_quit.
  65  * They expect to parse the whitespace before their parameters (if any).
  66  */
  67
  68 typedef int parmcondition_fnt(int ctoken, char *const *parmvalues, int *rtrue);
  69 static parmcondition_fnt pcf_glob, pcf_range, pcf_grep;
  70 /* all conditional functions return tokv_error for failure or 0 for success
  71  *  at parsing and testing, in which case *rtrue is set to 0 or 1.
  72  *  On success they have scanned up to and including the condition's
  73  *  terminating newline; the pcf_... functions expect to parse the whitespace
  74  *  between the parameter name and the condition's arguments.
  75  * Otherwise they return tokv_error.
  76  * The parameter-based conditionals take a list of parameter values
  77  * as obtained from the parameter functions and pa_parameter,
  78  * and do _not_ free it.
  79  */
  80
  81 typedef int parameter_fnt(int ptoken, char ***rvalues);
  82 static parameter_fnt pf_service;
  83 static parameter_fnt pf_callinguser, pf_serviceuser;
  84 static parameter_fnt pf_callinggroup, pf_servicegroup;
  85 static parameter_fnt pf_callingusershell, pf_serviceusershell;
  86 /* Parameter functions return tokv_error or 0 for success at parsing
  87  * and determining the value, in which case *rvalues is made to be
  88  * a mallocd null-terminated array of pointers to mallocd strings.
  89  * freeparm can be used to free such an array.
  90  */
  91
  92 typedef int builtinserviceparse_fnt(char ***rnewargs);
  93 static builtinserviceparse_fnt bispa_none, bispa_parameter;
  94 /* These parse the arguments to a builtin service, including the
  95  * newline at the end of the line.  *rnewargs will initially be
  96  * null, indicating that no arguments are to be set; the function
  97  * may store a mallocd array of mallocd strings in it,
  98  * containing the arguments it wishes to have set (null-pointer
  99  * terminated).
 100  */
 101
 102 static int yylex(void);
 103 /* Returns a token (which may be an eof or error exception) */
 104
 105 static directive_fnt *lr_dir;
 106 static parmcondition_fnt *lr_parmcond;
 107 static builtinserviceparse_fnt *lr_bispa;
 108 static builtinserviceexec_fnt *lr_bisexec;
 109 static parameter_fnt *lr_parameter;
 110 static int lr_loglevel, lr_logfacility, lr_min, lr_max, *lr_flag;
 111 static int lr_flagval, lr_controlend;
 112 static int lr_fdwant_readwrite; /* -1=never, 0=opt, 1=always */
 113
 114 /* Forward declarations of things used in lexer and parser */
 115
 116 struct parser_state {
 117   int lineno, reportlineno, notedreferer, isinternal;
 118   const char *filename;
 119   struct stat filestab;
 120   YY_BUFFER_STATE ybuf;
 121   struct parser_state *upstate;
 122 };
 123
 124 static struct parser_state *cstate;
 125
 126 struct error_handling {
 127   int handling; /* One of the error handling modes tokt_ehandlemode */
 128   int logfacility, loglevel;
 129   int filekeep; /* File is in use by higher-level errors-push, leave it open */
 130   FILE *file;
 131   char *filename;
 132 };
 133
 134 static struct error_handling eh = { tokv_word_errorstostderr, 0,0,0,0,0 };
 135
 136 static int dequote(char *inplace);
 137 static void countnewlines(void);
 138
 139 #define YY_NO_INPUT
 140
 141 %}
 142
 143 %option noyywrap
 144 %option nounput
 145
 146 %%
 147
 148 reject { lr_dir= df_reject; return tokv_word_reject; }
 149 execute-from-directory { lr_dir= df_executefromdirectory; return tokv_word_executefromdirectory; }
 150 execute-from-path { lr_dir= df_executefrompath; return tokv_word_executefrompath; }
 151 execute-builtin { lr_dir= df_executebuiltin; return tokv_word_executebuiltin; }
 152 errors-to-stderr { lr_dir= df_errorstostderr; return tokv_word_errorstostderr; }
 153 errors-to-syslog { lr_dir= df_errorstosyslog; return tokv_word_errorstosyslog; }
 154 errors-to-file { lr_dir= df_errorstofile; return tokv_word_errorstofile; }
 155 include-lookup-quote-old { lr_dir= dfg_lookupquotemode; return tokv_word_includelookupquoteold; }
 156 include-lookup-quote-new { lr_dir= dfg_lookupquotemode; return tokv_word_includelookupquotenew; }
 157 require-fd { lr_dir= dfg_fdwant; lr_fdwant_readwrite=1; return tokv_word_requirefd; }
 158 allow-fd { lr_dir= dfg_fdwant; lr_fdwant_readwrite=0; return tokv_word_allowfd; }
 159 null-fd { lr_dir= dfg_fdwant; lr_fdwant_readwrite=0; return tokv_word_nullfd; }
 160 reject-fd { lr_dir= dfg_fdwant; lr_fdwant_readwrite=-1; return tokv_word_rejectfd; }
 161 ignore-fd { lr_dir= dfg_fdwant; lr_fdwant_readwrite=-1; return tokv_word_ignorefd; }
 162 set-environment { lr_dir= dfg_setflag; lr_flag= &setenvironment; lr_flagval= 1; return tokv_word_setenvironment; }
 163 no-set-environment { lr_dir= dfg_setflag; lr_flag= &setenvironment; lr_flagval= 0; return tokv_word_nosetenvironment; }
 164 suppress-args { lr_dir= dfg_setflag; lr_flag= &suppressargs; lr_flagval= 1; return tokv_word_suppressargs; }
 165 no-suppress-args { lr_dir= dfg_setflag; lr_flag= &suppressargs; lr_flagval= 0; return tokv_word_nosuppressargs; }
 166 disconnect-hup { lr_dir= dfg_setflag; lr_flag= &disconnecthup; lr_flagval= 1; return tokv_word_disconnecthup; }
 167 no-disconnect-hup { lr_dir= dfg_setflag; lr_flag= &disconnecthup; lr_flagval= 0; return tokv_word_nodisconnecthup; }
 168 cd { lr_dir= df_cd; return tokv_word_cd; }
 169 user-rcfile { lr_dir= df_userrcfile; return tokv_word_userrcfile; }
 170 include { lr_dir= df_include; return tokv_word_include; }
 171 include-ifexist { lr_dir= df_include; return tokv_word_includeifexist; }
 172 include-lookup { lr_dir= df_includelookup; return tokv_word_includelookup; }
 173 include-lookup-all { lr_dir= df_includelookup; return tokv_word_includelookupall; }
 174 include-directory { lr_dir= df_includedirectory; return tokv_word_includedirectory; }
 175 message { lr_dir= df_message; return tokv_word_message; }
 176 _include-sysconfig { lr_dir= df_include; return tokv_word_includesysconfig; }
 177 _include-user-rcfile { lr_dir= dfi_includeuserrcfile; return tokv_word_includeuserrcfile; }
 178 _include-client-config { lr_dir= dfi_includeclientconfig; return tokv_word_includeclientconfig; }
 179 quit { lr_dir= df_quit; return tokv_word_quit; }
 180 eof { lr_dir= df_eof; return tokv_word_eof; }
 181 if { lr_dir= df_if; return tokv_word_if; }
 182 catch-quit { lr_dir= df_catchquit; return tokv_word_catchquit; }
 183 errors-push { lr_dir= df_errorspush; return tokv_word_errorspush; }
 184 elif { lr_controlend= tokv_word_if; return tokv_word_elif; }
 185 else { lr_controlend= tokv_word_if; return tokv_word_else; }
 186 fi { lr_controlend= tokv_word_if; return tokv_word_fi; }
 187 hctac { lr_controlend= tokv_word_catchquit; return tokv_word_hctac; }
 188 srorre { lr_controlend= tokv_word_errorspush; return tokv_word_srorre; }
 189 glob { lr_parmcond= pcf_glob; return tokv_word_glob; }
 190 range { lr_parmcond= pcf_range; return tokv_word_range; }
 191 grep { lr_parmcond= pcf_grep; return tokv_word_grep; }
 192 environment { lr_bispa= bispa_none; lr_bisexec= bisexec_environment; return tokv_word_environment; }
 193 parameter { lr_bispa= bispa_parameter; lr_bisexec= bisexec_parameter; return tokv_word_parameter; }
 194 version { lr_bispa= bispa_none; lr_bisexec= bisexec_version; return tokv_word_version; }
 195 toplevel { lr_bispa= bispa_none; lr_bisexec= bisexec_toplevel; return tokv_word_toplevel; }
 196 override { lr_bispa= bispa_none; lr_bisexec= bisexec_override; return tokv_word_override; }
 197 shutdown { lr_bispa= bispa_none; lr_bisexec= bisexec_shutdown; return tokv_word_shutdown; }
 198 reset { lr_bispa= bispa_none; lr_bisexec= bisexec_reset; lr_dir= df_reset; return tokv_word_reset; }
 199 execute { lr_bispa= bispa_none; lr_bisexec= bisexec_execute; lr_dir= df_execute; return tokv_word_execute; }
 200 help { lr_bispa= bispa_none; lr_bisexec= bisexec_help; return tokv_word_help; }
 201 service { lr_parameter= pf_service; return tokv_word_service; }
 202 calling-user { lr_parameter= pf_callinguser; return tokv_word_callinguser; }
 203 calling-group { lr_parameter= pf_callinggroup; return tokv_word_callinggroup; }
 204 calling-user-shell { lr_parameter= pf_callingusershell; return tokv_word_callingusershell; }
 205 service-user { lr_parameter= pf_serviceuser; return tokv_word_serviceuser; }
 206 service-group { lr_parameter= pf_servicegroup; return tokv_word_servicegroup; }
 207 service-user-shell { lr_parameter= pf_serviceusershell; return tokv_word_serviceusershell; }
 208 debug { lr_loglevel= LOG_DEBUG; return tokv_syslog_debug; }
 209 info { lr_loglevel= LOG_INFO; return tokv_syslog_info; }
 210 notice { lr_loglevel= LOG_NOTICE; return tokv_syslog_notice; }
 211 warn(ing)? { lr_loglevel= LOG_WARNING; return tokv_syslog_warning; }
 212 err { lr_loglevel= LOG_ERR; return tokv_syslog_err; }
 213 crit { lr_loglevel= LOG_CRIT; return tokv_syslog_crit; }
 214 alert { lr_loglevel= LOG_ALERT; return tokv_syslog_alert; }
 215 emerg|panic { lr_loglevel= LOG_EMERG; return tokv_syslog_emerg; }
 216 auth(priv)?|security { lr_logfacility= LOG_AUTHPRIV; return tokv_syslog_authpriv; }
 217 cron { lr_logfacility= LOG_CRON; return tokv_syslog_cron; }
 218 daemon { lr_logfacility= LOG_DAEMON; return tokv_syslog_daemon; }
 219 kern(el)? { lr_logfacility= LOG_KERN; return tokv_syslog_kern; }
 220 lpr { lr_logfacility= LOG_LPR; return tokv_syslog_lpr; }
 221 mail { lr_logfacility= LOG_MAIL; return tokv_syslog_mail; }
 222 news { lr_logfacility= LOG_NEWS; return tokv_syslog_news; }
 223 syslog { lr_logfacility= LOG_SYSLOG; return tokv_syslog_syslog; }
 224 user { lr_logfacility= LOG_USER; return tokv_syslog_user; }
 225 uucp { lr_logfacility= LOG_UUCP; return tokv_syslog_uucp; }
 226 local0 { lr_logfacility= LOG_LOCAL0; return tokv_syslog_local0; }
 227 local1 { lr_logfacility= LOG_LOCAL1; return tokv_syslog_local1; }
 228 local2 { lr_logfacility= LOG_LOCAL2; return tokv_syslog_local2; }
 229 local3 { lr_logfacility= LOG_LOCAL3; return tokv_syslog_local3; }
 230 local4 { lr_logfacility= LOG_LOCAL4; return tokv_syslog_local4; }
 231 local5 { lr_logfacility= LOG_LOCAL5; return tokv_syslog_local5; }
 232 local6 { lr_logfacility= LOG_LOCAL6; return tokv_syslog_local6; }
 233 local7 { lr_logfacility= LOG_LOCAL7; return tokv_syslog_local7; }
 234 read { return tokv_word_read; }
 235 write { return tokv_word_write; }
 236 \$ { return tokv_dollar; }
 237 stdin {  lr_max= lr_min= 0; return tokv_word_stdin; }
 238 stdout {  lr_max= lr_min= 1; return tokv_word_stdout; }
 239 stderr {  lr_max= lr_min= 2; return tokv_word_stderr; }
 240 \( { return tokv_openparen; }
 241 \) { return tokv_closeparen; }
 242 \! { return tokv_not; }
 243 \& { return tokv_and; }
 244 \| { return tokv_or; }
 245 error { lr_dir= df_error; lr_loglevel= LOG_ERR; return tokv_word_error; }
 246
 247
 248
 249 [0-9]{1,8}              {
 250                           char *ep;
 251                           lr_min=lr_max= (int)strtoul(yytext,&ep,10);
 252                           assert(!*ep);
 253                           return tokv_ordinal;
 254                         }
 255 [0-9]{1,8}-[0-9]{1,8}   {
 256                           char *ep;
 257                           lr_min= (int)strtoul(yytext,&ep,10);
 258                           assert(*ep == HYPHEN);
 259                           ep++;  assert(*ep);
 260                           lr_max= (int)strtoul(ep,&ep,10);
 261                           assert(!*ep);
 262                           if (lr_max < lr_min)
 263                             return parseerrprint("fd range has min > max");
 264                           return tokv_fdrange;
 265                         }
 266 [0-9]{1,8}-             {
 267                           char *ep;
 268                           lr_min= (int)strtoul(yytext,&ep,10);
 269                           assert(*ep == HYPHEN);
 270                           ep++;  assert(!*ep);
 271                           lr_max=-1;
 272                           return tokv_fdstoend;
 273                         }
 274 ([\ \t]*\\[\ \t]*\n[\ \t]*)+    countnewlines(); return tokv_lwsp;
 275 [\ \t]+                         return tokv_lwsp;
 276 [\ \t]*\n               cstate->lineno++; return tokv_newline;
 277 [\ \t]*\#[^\n]*\n       cstate->lineno++; return tokv_newline;
 278 [\ \t]*\#[^\n]*         return parseerrprint("missing newline at eof after comment");
 279 \"([^\\\"\n]|\\[a-z]|\\[0-9]{3}|\\x[0-9A-Fa-f]{2}|\\[[:punct:]]|\\[ \t]*\n)*\" {
 280                           countnewlines();
 281                           return dequote(yytext);
 282                         }
 283 [^\ \t\n\\\"]+          return tokv_barestring;
 284 <<EOF>>                 return tokv_eof;
 285 \"                      return parseerrprint("misquoted or unterminated string");
 286 \\                      return parseerrprint("unexpected backslash");
 287 .                       abort(); /* expect lex warning "rule cannot be matched" */
 288
 289
 290 %%
 291
 292 const char *const builtinservicehelpstrings[]= {
 293   "environment",
 294   "parameter <parameter>",
 295   "version",
 296   "toplevel",
 297   "override",
 298   "shutdown",
 299   "reset",
 300   "execute",
 301   "help",
 302    0
 303 };
 304
 305 #include "parser.c"
 306