/*
 * http_alias.c: Stuff for dealing with directory aliases
 * 
 * All code contained herein is covered by the Copyright as distributed
 * in the README file in the main directory of the distribution of 
 * NCSA HTTPD.
 *
 * Based on NCSA HTTPd 1.3 by Rob McCool
 * 
 *  04-06-95 blong
 * 	Added Saved_ variables to allow reset of aliases to configured 
 *	only.  save_aliases is called from http_config, and 
 *	reset_to_saved_alias is called in the initialization of 
 *	transactions.
 */


#include "httpd.h"
#include <sys/types.h>
#include <sys/stat.h>

/* These values are experimentally determined. They seem to be constant
   for a given platform. */

#if defined(SOLARIS2)
#define AFS_ST_DEV 1
#elif defined(ULTRIX)
#define AFS_ST_DEV -30975
#elif defined(SUNOS4)
#define AFS_ST_DEV 1
#endif

typedef struct {
    char fake[MAX_STRING_LEN];
    char real[MAX_STRING_LEN];
    int script;
} alias;

static int Saved_num_alias = 0;
static int num_a = 0;
static alias a[MAX_ALIASES];
static int Saved_num_redirect = 0;
static int num_v = 0;
static alias v[MAX_ALIASES];
static int Saved_num_afs = 0;
static int num_afs = 0;
static alias afs[MAX_ALIASES];

/* To send stat() information to http_script.c */
int dirs_in_alias;

void reset_aliases() {
    num_a = 0;
    num_v = 0;
    num_afs = 0;
}

void save_aliases() {
    Saved_num_alias = num_a;
    Saved_num_redirect = num_v;
    Saved_num_afs = num_afs;
}

void reset_to_saved_aliases() {
    num_a = Saved_num_alias;
    num_v = Saved_num_redirect;
    num_afs = Saved_num_afs;
}

void add_alias(char *f, char *r, int is_script) {
    if (num_a >= MAX_ALIASES)
      num_a = Saved_num_alias;
    strcpy(a[num_a].fake,f);

    a[num_a].script = is_script;
    if(r[0] != '/') 
        make_full_path((is_script ? server_root : document_root),r,
                       a[num_a++].real);
    else
        strcpy(a[num_a++].real,r);
}

void add_afscheck(char *f, char *r, int is_script) {
    strcpy(afs[num_afs].fake,f);

    afs[num_afs].script = is_script;
    if(r[0] != '/') 
        make_full_path((is_script ? server_root : document_root),r,
                       afs[num_afs++].real);
    else
        strcpy(afs[num_afs++].real,r);
}

void add_redirect(char *f, char *url) {
    if (num_v >= MAX_ALIASES)
      num_v = Saved_num_redirect;
    strcpy(v[num_v].fake,f);
    strcpy(v[num_v++].real,url);
}

char fake[MAX_STRING_LEN + 2],real[MAX_STRING_LEN],dname[HUGE_STRING_LEN];

int translate_name(char *name, FILE *fd) {
    register int x,l;
    char filenametemp[MAX_STRING_LEN];
    char w[MAX_STRING_LEN];
    struct passwd *pw;

    getparents(name);

    for(x=0;x<num_v;x++) {
        l=strlen(v[x].fake);
        if(!strncmp(name,v[x].fake,l)) {
            strsubfirst(l,name,v[x].real);
            return REDIRECT_URL;
        }
    }

    for(x=0; x < num_a; x++) {
        l=strlen(a[x].fake);
        if(!strncmp(name,a[x].fake,l)) {
            strsubfirst(l,name,a[x].real);
            dirs_in_alias = count_dirs(a[x].real);
            return(a[x].script);
        }
    }

    strcpy(filenametemp, name);
    strsubfirst(0,filenametemp,document_root);
    for(x=0; x < num_afs; x++){
	 l=strlen(afs[x].fake);
	 if(!strncmp(name, afs[x].fake,l)){
	      if(file_is_in_afs(filenametemp)){
		   /* It is, so it's ok */
		   strsubfirst(0,name,document_root);
	      }
	      else{
		   /* Not! go away */
		   strcpy(name, afs[x].real);
	      }
	      return STD_DOCUMENT;
	 }
    }

    if((user_dir[0]) && (name[0] == '/') && (name[1] == '~')) {
        strcpy(dname,&name[2]);
        getword(w,dname,'/');
        if(!(pw=getpwnam(w)))
            die(NOT_FOUND,name,fd);
        fake[0] = '/';
        fake[1] = '~';
        strcpy(&fake[2],w);
        make_full_path(pw->pw_dir,user_dir,real);
        add_alias(fake,real,STD_DOCUMENT);
        strsubfirst(strlen(w) + 2,name,real);
        return STD_DOCUMENT;
    }
    /* no alias, add document root */
    strsubfirst(0,name,document_root);
    return STD_DOCUMENT;
}

int file_is_in_afs(char *filename){
  int statr;
  struct stat finfo;

  statr = stat(filename,&finfo);
  if (statr != -1 && finfo.st_dev != AFS_ST_DEV) {
    /* Hey! That's not in AFS */
    return 0;

    /* This code is a suggestion of how we might do this in
       the future. It would allow us to return an explanation of
       *why* the file was refused. */
    /* log_reason("access denied since file is not in afs",file); */
    /* unmunge_name(file); */
    /* die(FORBIDDEN,file,fd); */

  }  else {
    /* Ok, cool */
    return 1;
  }
}

void unmunge_name(char *name) {
    register int x,l;

    l=strlen(document_root);
    if(!strncmp(name,document_root,l)) {
        strsubfirst(l,name,"");
        if(!name[0]) {
            name[0] = '/';
            name[1] = '\0';
        }
        return;
    }
    for(x=0;x < num_a; x++) {
        l=strlen(a[x].real);
        if(!strncmp(name,a[x].real,l)) {
            strsubfirst(l,name,a[x].fake);
            if(!name[0]) {
                name[0] = '/';
                name[1] = '\0';
            }
            return;
        }
    }
}