config.c

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/*
 * Asterisk -- A telephony toolkit for Linux.
 *
 * Configuration File Parser
 * 
 * Copyright (C) 1999, Mark Spencer
 *
 * Mark Spencer <markster@linux-support.net>
 *
 * This program is free software, distributed under the terms of
 * the GNU General Public License
 */

#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <time.h>
#include <asterisk/config.h>
#include <asterisk/options.h>
#include <asterisk/logger.h>
#include <asterisk/utils.h>
#include "asterisk.h"
#include "astconf.h"

#define MAX_INCLUDE_LEVEL 10

struct ast_category {
   char name[80];
   struct ast_variable *root;
   struct ast_category *next;
#ifdef PRESERVE_COMMENTS
   struct ast_comment *precomments;
   struct ast_comment *sameline;
#endif   
};

struct ast_config {
   /* Maybe this structure isn't necessary but we'll keep it
      for now */
   struct ast_category *root;
   struct ast_category *prev;
#ifdef PRESERVE_COMMENTS
   struct ast_comment *trailingcomments;
#endif   
};

#ifdef PRESERVE_COMMENTS
struct ast_comment_struct
{
   struct ast_comment *root;
   struct ast_comment *prev;
};
#endif

static char *strip(char *buf)
{
   char *start;
   /* Strip off trailing whitespace, returns, etc */
   while(!ast_strlen_zero(buf) && (buf[strlen(buf)-1]<33))
      buf[strlen(buf)-1] = '\0';
   start = buf;
   /* Strip off leading whitespace, returns, etc */
   while(*start && (*start < 33))
      *start++ = '\0';
   return start;
}

#ifdef PRESERVE_COMMENTS
static void free_comments(struct ast_comment *com)
{
   struct ast_comment *l;
   while (com) {
      l = com;
      com = com->next;
      free(l);
   }
}
#endif

void ast_destroy(struct ast_config *ast)
{
   struct ast_category *cat, *catn;
   struct ast_variable *v, *vn;

   if (!ast)
      return;

   cat = ast->root;
   while(cat) {
      v = cat->root;
      while(v) {
         vn = v;
         free(v->name);
         free(v->value);
#ifdef PRESERVE_COMMENTS
         free_comments(v->precomments);
         free_comments(v->sameline);
#endif         
         v = v->next;
         free(vn);
      }
      catn = cat;
#ifdef PRESERVE_COMMENTS
      free_comments(cat->precomments);
      free_comments(cat->sameline);
#endif      
      cat = cat->next;
      free(catn);
   }
#ifdef PRESERVE_COMMENTS
   free_comments(ast->trailingcomments);
#endif   
   free(ast);
}

int ast_true(char *s)
{
   if (!s)
      return 0;
   /* Determine if this is a true value */
   if (!strcasecmp(s, "yes") ||
       !strcasecmp(s, "true") ||
      !strcasecmp(s, "y") ||
      !strcasecmp(s, "t") ||
      !strcasecmp(s, "1"))
         return -1;
   return 0;
}

int ast_false(char *s)
{
   if (!s)
      return 0;
   /* Determine if this is a false value */
   if (!strcasecmp(s, "no") ||
       !strcasecmp(s, "false") ||
      !strcasecmp(s, "n") ||
      !strcasecmp(s, "f") ||
      !strcasecmp(s, "0"))
         return -1;
   return 0;
}

struct ast_variable *ast_variable_browse(struct ast_config *config, char *category)
{
   struct ast_category *cat;
   cat = config->root;
   while(cat) {
      if (cat->name == category)
         return cat->root;
      cat = cat->next;
   }
   cat = config->root;
   while(cat) {
      if (!strcasecmp(cat->name, category))
         return cat->root;
      cat = cat->next;
   }
   return NULL;
}

char *ast_variable_retrieve(struct ast_config *config, char *category, char *value)
{
   struct ast_variable *v;
   if (category) {
      v = ast_variable_browse(config, category);
      while (v) {
         if (value == v->name)
            return v->value;
         v=v->next;
      }
      v = ast_variable_browse(config, category);
      while (v) {
         if (!strcasecmp(value, v->name))
            return v->value;
         v=v->next;
      }
   } else {
      struct ast_category *cat;
      cat = config->root;
      while(cat) {
         v = cat->root;
         while (v) {
            if (!strcasecmp(value, v->name))
               return v->value;
            v=v->next;
         }
         cat = cat->next;
      }
   }
   return NULL;
}

#ifdef PRESERVE_COMMENTS
int ast_variable_delete(struct ast_config *cfg, char *category, char *variable, char *value)
{
   struct ast_variable *v, *pv, *bv, *bpv;
   struct ast_category *cat;
   cat = cfg->root;
   while(cat) {
      if (cat->name == category) {
         break;
      }
      cat = cat->next;
   }
   if (!cat) {
      cat = cfg->root;
      while(cat) {
         if (!strcasecmp(cat->name, category)) {
            break;
         }
         cat = cat->next;
      }
   }
   if (!cat)
      return -1;
   v = cat->root;
   pv = NULL;
   while (v) {
      if ((variable == v->name) && (!value || !strcmp(v->value, value)))
         break;
      pv = v;
      v=v->next;
   }
   if (!v) {
      /* Get the last one that looks like it */
      bv = NULL;
      bpv = NULL;
      v = cat->root;
      pv = NULL;
      while (v) {
         if (!strcasecmp(variable, v->name) && (!value || !strcmp(v->value, value))) {
            bv = v;
            bpv = pv;
         }
         pv = v;
         v=v->next;
      }
      v = bv;
   }

   if (v) {
      /* Unlink from original position */
      if (pv) 
         pv->next = v->next;
      else
         cat->root = v->next;
      v->next = NULL;
      free(v->name);
      if (v->value)
         free(v->value);
      free_comments(v->sameline);
      free_comments(v->precomments);
      return 0;
   }
   return -1;
}

int ast_category_delete(struct ast_config *cfg, char *category)
{
   struct ast_variable *v, *pv;
   struct ast_category *cat, *cprev;
   cat = cfg->root;
   cprev = NULL;
   while(cat) {
      if (cat->name == category) {
         break;
      }
      cprev = cat;
      cat = cat->next;
   }
   if (!cat) {
      cat = cfg->root;
      cprev = NULL;
      while(cat) {
         if (!strcasecmp(cat->name, category)) {
            break;
         }
         cprev = cat;
         cat = cat->next;
      }
   }
   if (!cat)
      return -1;
   /* Unlink it */
   if (cprev)
      cprev->next = cat->next;
   else
      cfg->root = cat->next;
   v = cat->root;
   while (v) {
      pv = v;
      v=v->next;
      if (pv->value)
         free(pv->value);
      if (pv->name)
         free(pv->name);
      free_comments(pv->sameline);
      free_comments(pv->precomments);
      free(pv);
   }
   free_comments(cat->sameline);
   free_comments(cat->precomments);
   free(cat);
   return 0;
}

struct ast_variable *ast_variable_append_modify(struct ast_config *config, char *category, char *variable, char *value, int newcat, int newvar, int move)
{
   struct ast_variable *v, *pv=NULL, *bv, *bpv;
   struct ast_category *cat, *pcat;
   cat = config->root;
   if (!newcat) {
      while(cat) {
         if (cat->name == category) {
            break;
         }
         cat = cat->next;
      }
      if (!cat) {
         cat = config->root;
         while(cat) {
            if (!strcasecmp(cat->name, category)) {
               break;
            }
            cat = cat->next;
         }
      }
   }
   if (!cat) {
      cat = malloc(sizeof(struct ast_category));
      if (!cat)
         return NULL;
      memset(cat, 0, sizeof(struct ast_category));
      strncpy(cat->name, category, sizeof(cat->name));
      if (config->root) {
         /* Put us at the end */
         pcat = config->root;
         while(pcat->next)
            pcat = pcat->next;
         pcat->next = cat;
      } else {
         /* We're the first one */
         config->root = cat;
      }
         
   }
   if (!newvar) {
      v = cat->root;
      pv = NULL;
      while (v) {
         if (variable == v->name)
            break;
         pv = v;
         v=v->next;
      }
      if (!v) {
         /* Get the last one that looks like it */
         bv = NULL;
         bpv = NULL;
         v = cat->root;
         pv = NULL;
         while (v) {
            if (!strcasecmp(variable, v->name)) {
               bv = v;
               bpv = pv;
            }
            pv = v;
            v=v->next;
         }
         v = bv;
      }
   } else v = NULL;
   if (v && move) {
      /* Unlink from original position */
      if (pv) 
         pv->next = v->next;
      else
         cat->root = v->next;
      v->next = NULL;
   }
   if (!v) {
      v = malloc(sizeof(struct ast_variable));
      if (!v)
         return NULL;
      memset(v, 0, sizeof(struct ast_variable));
      v->name = strdup(variable);
      move = 1;
   }
   if (v->value)
      free(v->value);
   if (value)
      v->value = strdup(value);
   else
      v->value = strdup("");
   if (move) {
      if (cat->root) {
         pv = cat->root;
         while (pv->next) 
            pv = pv->next;
         pv->next = v;
      } else {
         cat->root = v;
      }
   }
   return v;
}
#endif      

int ast_category_exist(struct ast_config *config, char *category_name)
{
   struct ast_category *category = NULL;

   category = config->root;

   while(category) {
      if (!strcasecmp(category->name,category_name)) 
         return 1;
      category = category->next;
   } 

   return 0;
}

#ifdef PRESERVE_COMMENTS
static struct ast_comment *build_comment(char *cmt)
{
   struct ast_comment *c;
   int len = strlen(cmt) + 1;
   c = malloc(sizeof(struct ast_comment) + len);
   if (c) {
      /* Memset the header */
      memset(c, 0, sizeof(struct ast_comment));
      /* Copy the rest */
      strcpy(c->cmt, cmt);
   }
   return c;
}
#endif

static struct ast_config *__ast_load(char *configfile, struct ast_config *tmp, struct ast_category **_tmpc, struct ast_variable **_last, int includelevel
#ifdef PRESERVE_COMMENTS
, struct ast_comment_struct *acs
#endif
);

static int cfg_process(struct ast_config *tmp, struct ast_category **_tmpc, struct ast_variable **_last, char *buf, int lineno, char *configfile, int includelevel 
#ifdef PRESERVE_COMMENTS
,struct ast_comment_struct *acs
#endif
)
{
   char *c;
   char *cur;
   struct ast_variable *v;
#ifdef PRESERVE_COMMENTS
   struct ast_comment *com = NULL;
#endif   
   int object;
   /* Strip off lines using ; as comment */
   c = strchr(buf, ';');
   if (c) {
      *c = '\0';
#ifdef PRESERVE_COMMENTS
      c++;
      if (*c != '!')
         com = build_comment(c);
#endif         
   }
   cur = strip(buf);
   if (!ast_strlen_zero(cur)) {
      /* Actually parse the entry */
      if (cur[0] == '[') {
         /* A category header */
         c = strchr(cur, ']');
         if (c) {
            *c = 0;
            *_tmpc = malloc(sizeof(struct ast_category));
            if (!*_tmpc) {
               ast_destroy(tmp);
               ast_log(LOG_WARNING,
                  "Out of memory, line %d\n", lineno);
               return -1;
            }
            memset(*_tmpc, 0, sizeof(struct ast_category));
            strncpy((*_tmpc)->name, cur+1, sizeof((*_tmpc)->name) - 1);
            (*_tmpc)->root =  NULL;
#ifdef PRESERVE_COMMENTS
            (*_tmpc)->precomments = acs->root;
            (*_tmpc)->sameline = com;
#endif            
            if (!tmp->prev)
               tmp->root = *_tmpc;
            else
               tmp->prev->next = *_tmpc;

            tmp->prev = *_tmpc;
#ifdef PRESERVE_COMMENTS
            acs->root = NULL;
            acs->prev = NULL;
#endif            
            *_last =  NULL;
         } else {
            ast_log(LOG_WARNING, 
               "parse error: no closing ']', line %d of %s\n", lineno, configfile);
         }
      } else if (cur[0] == '#') {
         /* A directive */
         cur++;
         c = cur;
         while(*c && (*c > 32)) c++;
         if (*c) {
            *c = '\0';
            c++;
            /* Find real argument */
            while(*c  && (*c < 33)) c++;
            if (!*c)
               c = NULL;
         } else 
            c = NULL;
         if (!strcasecmp(cur, "include")) {
            /* A #include */
            if (c) {
               while((*c == '<') || (*c == '>') || (*c == '\"')) c++;
               /* Get rid of leading mess */
               cur = c;
               while(!ast_strlen_zero(cur)) {
                  c = cur + strlen(cur) - 1;
                  if ((*c == '>') || (*c == '<') || (*c == '\"'))
                     *c = '\0';
                  else
                     break;
               }
               if (includelevel < MAX_INCLUDE_LEVEL) {
                  __ast_load(cur, tmp, _tmpc, _last, includelevel + 1
#ifdef PRESERVE_COMMENTS
                  ,acs
#endif
                  );
               } else 
                  ast_log(LOG_WARNING, "Maximum Include level (%d) exceeded\n", includelevel);
            } else
               ast_log(LOG_WARNING, "Directive '#include' needs an argument (filename) at line %d of %s\n", lineno, configfile);
            /* Strip off leading and trailing "'s and <>'s */
         } else 
            ast_log(LOG_WARNING, "Unknown directive '%s' at line %d of %s\n", cur, lineno, configfile);
      } else {
         /* Just a line (variable = value) */
         if (!*_tmpc) {
            ast_log(LOG_WARNING,
               "parse error: No category context for line %d of %s\n", lineno, configfile);
            ast_destroy(tmp);
            return -1;
         }
         c = strchr(cur, '=');
         if (c) {
            *c = 0;
            c++;
            /* Ignore > in => */
            if (*c== '>') {
               object = 1;
               c++;
            } else
               object = 0;
            v = malloc(sizeof(struct ast_variable));
            if (v) {
               memset(v, 0, sizeof(struct ast_variable));
               v->next = NULL;
               v->name = strdup(strip(cur));
               v->value = strdup(strip(c));
               v->lineno = lineno;
               v->object = object;
               /* Put and reset comments */
#ifdef PRESERVE_COMMENTS
               v->precomments = acs->root;
               v->sameline = com;
               acs->prev = NULL;
               acs->root = NULL;
#endif               
               v->blanklines = 0;
               if (*_last)
                  (*_last)->next = v;
               else
                  (*_tmpc)->root = v;
               *_last = v;
            } else {
               ast_destroy(tmp);
               ast_log(LOG_WARNING, "Out of memory, line %d\n", lineno);
               return -1;
            }
         } else {
            ast_log(LOG_WARNING, "No '=' (equal sign) in line %d of %s\n", lineno, configfile);
         }
                                          
      }
   } else {
      /* store any comments if there are any */
#ifdef PRESERVE_COMMENTS
      if (com) {
         if (acs->prev)
            acs->prev->next = com;
         else
            acs->root = com;
         acs->prev = com;
      } else {
      if (*_last) 
         (*_last)->blanklines++;

      }
#endif
   }
   return 0;
}

#ifdef PRESERVE_COMMENTS
static void dump_comments(FILE *f, struct ast_comment *comment)
{
   while (comment) {
      fprintf(f, ";%s", comment->cmt);
      comment = comment->next;
   }
}
#endif

int ast_save(char *configfile, struct ast_config *cfg, char *generator)
{
   FILE *f;
   char fn[256];
   char date[256];
   time_t t;
   struct ast_variable *var;
   struct ast_category *cat;
   int blanklines = 0;
   if (configfile[0] == '/') {
      strncpy(fn, configfile, sizeof(fn)-1);
   } else {
      snprintf(fn, sizeof(fn), "%s/%s", AST_CONFIG_DIR, configfile);
   }
   time(&t);
   strncpy(date, ctime(&t), sizeof(date));
   if ((f = fopen(fn, "w"))) {
      if ((option_verbose > 1) && !option_debug)
         ast_verbose(  VERBOSE_PREFIX_2 "Saving '%s': ", fn);
      fprintf(f, ";!\n");
      fprintf(f, ";! Automatically generated configuration file\n");
      fprintf(f, ";! Filename: %s (%s)\n", configfile, fn);
      fprintf(f, ";! Generator: %s\n", generator);
      fprintf(f, ";! Creation Date: %s", date);
      fprintf(f, ";!\n");
      cat = cfg->root;
      while(cat) {
#ifdef PRESERVE_COMMENTS
         /* Dump any precomments */
         dump_comments(f, cat->precomments);
#endif
         /* Dump section with any appropriate comment */
#ifdef PRESERVE_COMMENTS
         if (cat->sameline) 
            fprintf(f, "[%s]  ; %s\n", cat->name, cat->sameline->cmt);
         else
#endif
            fprintf(f, "[%s]\n", cat->name);
         var = cat->root;
         while(var) {
#ifdef PRESERVE_COMMENTS
            dump_comments(f, var->precomments);
#endif            
            if (var->sameline) 
               fprintf(f, "%s %s %s  ; %s\n", var->name, (var->object ? "=>" : "="), var->value, var->sameline->cmt);
            else  
               fprintf(f, "%s %s %s\n", var->name, (var->object ? "=>" : "="), var->value);
            if (var->blanklines) {
               blanklines = var->blanklines;
               while (blanklines) {
                  fprintf(f, "\n");
                  blanklines--;
               }
            }
               
            var = var->next;
         }
#if 0
         /* Put an empty line */
         fprintf(f, "\n");
#endif
         cat = cat->next;
      }
#ifdef PRESERVE_COMMENTS
      dump_comments(f, cfg->trailingcomments);
#endif      
   } else {
      if (option_debug)
         printf("Unable to open for writing: %s\n", fn);
      else if (option_verbose > 1)
         printf( "Unable to write (%s)", strerror(errno));
      return -1;
   }
   fclose(f);
   return 0;
}

static struct ast_config *__ast_load(char *configfile, struct ast_config *tmp, struct ast_category **_tmpc, struct ast_variable **_last, int includelevel
#ifdef PRESERVE_COMMENTS
, struct ast_comment_struct *acs
#endif
)
{
   char fn[256];
   char buf[512];
   FILE *f;
   int lineno=0;
   int master=0;

   if (configfile[0] == '/') {
      strncpy(fn, configfile, sizeof(fn)-1);
   } else {
      snprintf(fn, sizeof(fn), "%s/%s", (char *)ast_config_AST_CONFIG_DIR, configfile);
   }
   if ((option_verbose > 1) && !option_debug) {
      ast_verbose(  VERBOSE_PREFIX_2 "Parsing '%s': ", fn);
      fflush(stdout);
   }
   if ((f = fopen(fn, "r"))) {
      if (option_debug)
         ast_log(LOG_DEBUG, "Parsing %s\n", fn);
      else if (option_verbose > 1)
         ast_verbose( "Found\n");
      if (!tmp) {
         tmp = malloc(sizeof(struct ast_config));
         if (tmp)
            memset(tmp, 0, sizeof(struct ast_config));

         master = 1;
      }
      if (!tmp) {
         ast_log(LOG_WARNING, "Out of memory\n");
         fclose(f);
         return NULL;
      }
      while(!feof(f)) {
         lineno++;
         if (fgets(buf, sizeof(buf), f)) {
            if (cfg_process(tmp, _tmpc, _last, buf, lineno, configfile, includelevel
#ifdef PRESERVE_COMMENTS
            , acs
#endif
            )) {
               fclose(f);
               return NULL;
            }
         }
      }
      fclose(f);     
   } else {
      if (option_debug)
         ast_log(LOG_DEBUG, "No file to parse: %s\n", fn);
      else if (option_verbose > 1)
         ast_verbose( "Not found (%s)\n", strerror(errno));
   }
#ifdef PRESERVE_COMMENTS
   if (master) {
      /* Keep trailing comments */
      tmp->trailingcomments = acs->root;
      acs->root = NULL;
      acs->prev = NULL;
   }
#endif
   return tmp;
}

struct ast_config *ast_load(char *configfile)
{
   struct ast_category *tmpc=NULL;
   struct ast_variable *last = NULL;
#ifdef PRESERVE_COMMENTS
   struct ast_comment_struct acs = { NULL, NULL };
#endif   
   return __ast_load(configfile, NULL, &tmpc, &last, 0 
#ifdef PRESERVE_COMMENTS
   ,&acs
#endif
   );
}

char *ast_category_browse(struct ast_config *config, char *prev)
{  
   struct ast_category *cat;
   if (!prev) {
      if (config->root)
         return config->root->name;
      else
         return NULL;
   }
   cat = config->root;
   while(cat) {
      if (cat->name == prev) {
         if (cat->next)
            return cat->next->name;
         else
            return NULL;
      }
      cat = cat->next;
   }
   cat = config->root;
   while(cat) {
      if (!strcasecmp(cat->name, prev)) {
         if (cat->next)
            return cat->next->name;
         else
            return NULL;
      }
      cat = cat->next;
   }
   return NULL;
}

---