/*
	Extension to POP server for virtual mail server management.
	Written by Jacques Gelinas jacques@solucorp.qc.ca

	Use as needed :-)
	This does not supersede the original POP server license. It only
	apply to this file.
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <pwd.h>
#include <time.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <syslog.h>
#include <netdb.h>
#include "pop3.h"


void strlwr (char *dst, const char *src, int size)
{
	size--;
	while (*src != '\0' && size > 0){
		*dst++ = tolower(*src);
		src++;
		size--;
	}
	*dst = '\0';
}
/*
	Extract which virtual host is expected by the POP client.
	Return -1 if any error.
*/
int vmail_getourname(char *name, int sizename)
{
	int ret = -1;
	struct sockaddr_in adr;
	unsigned int len = sizeof(adr);
	if (getsockname (0,(struct sockaddr*)&adr,&len) != -1){
		struct hostent *ent;
		/* syslog (LOG_ERR,"connexion de %d %x",adr.sin_port,adr.sin_addr); */
		ent = gethostbyaddr ((const char*)&adr.sin_addr
			,sizeof(adr.sin_addr.s_addr),AF_INET);
		/* syslog (LOG_DEBUG,"connexion de %p",ent); */
		if (ent != NULL){
			strlwr (name,ent->h_name,sizename);
			/* syslog (LOG_DEBUG,"connexion de %s",name); */
			ret = 0;
		}else{
			long a = ntohl (*(long*)(&adr.sin_addr));
			syslog (LOG_ERR,"Can't convert IP number %lu.%lu.%lu.%lu to name, using main domain"
				,(a>>24)&0xff,(a>>16)&0xff,(a>>8)&0xff,a&0xff);
		}
	}else{
		syslog (LOG_ERR,"getsockname failed (errno %m)");
	}
	return ret;
}
 
static int vmail_splitline (const char *line, char words[9][100])
{
	int nbword = 0;
	char *dst = words[0];
	int i;
	for (i=0; i<9; i++) words[i][0] = '\0';
	while (*line != '\0' && *line != '\n'){
		if (*line == ':'){
			line++;
			*dst = '\0';
			nbword++;
			dst = words[nbword];
		}else{
			*dst++ = *line++;
		}
	}
	*dst = '\0';
	return nbword;
}


/*
	Format the gecos field so it can be used as an email targer
	Turn all spaces into dots. 2 spaces are turnes into a single dot.
*/
static void vmail_formatgecos(const char *orig, char *mail_gecos)
{
	while (*orig != '\0'){
		if (isspace(*orig)){
			*mail_gecos++ = '.';
			orig++;
			while (isspace(*orig)) orig++;
		}else{
			*mail_gecos++ = *orig++;
		}
	}
	*mail_gecos = '\0';
}

/*
	Lookup a user in a file with the same layout as /etc/passwd
*/
struct passwd *vmail_getpwnam (
	const char *pwdfile,
	const char *shadow_file,
	const char *user,
	bool nocase,		// Case insensitive match of the user id
	bool match_gecos)	// Try to match the full name as well
{
	struct passwd *ret = NULL;
	FILE *fin = fopen (pwdfile,"r");
	if (fin != NULL){
		char buf[400];
		while (fgets(buf,sizeof(buf)-1,fin)!=NULL){
			static char words[9][100];
			static struct passwd p;
			vmail_splitline (buf,words);
			char gecos[100];
			if (match_gecos) vmail_formatgecos(words[4],gecos);
			if (strcmp(user,words[0])==0
				|| (nocase && strcasecmp(user,words[0])==0)
				|| (match_gecos && strcasecmp(user,gecos)==0)){
				p.pw_name = words[0];
				p.pw_passwd = words[1];
				p.pw_uid = atoi(words[2]);
				p.pw_gid = atoi(words[3]);
				p.pw_gecos = words[4];
				p.pw_dir = words[5];
				p.pw_shell = words[6];
				ret = &p;
				break;
			}
		}
		fclose (fin);
		if (ret != NULL){
			fin = fopen (shadow_file,"r");
			if (fin != NULL){
				while (fgets(buf,sizeof(buf)-1,fin)!=NULL){
					char words[9][100];
					vmail_splitline (buf,words);
					if (strcmp(user,words[0])==0){
						int last = atoi(words[2]);
						int expire = atoi(words[6]);
						int disable = atoi(words[7]);
						time_t tim = time(NULL);
						int days = tim/(24*60*60);
						if ((disable > 0 && disable < days)
							|| (expire > 0
								&& last > 0
								&& last + expire < days)){
							strcpy (ret->pw_passwd,"*");
						}else{
							strcpy (ret->pw_passwd,words[1]);
						}
						break;
					}
				}
				fclose (fin);
			}
		}
	}
	return ret;
}