util.c

#include <stdio.h>
#include <ctype.h>
#include <string.h>
#include <pwd.h>
#include <syslog.h>
#include <unistd.h>
#include <netdb.h>

#ifdef SHADOWPWD
#include <shadow.h>
#endif

#include "pop3.h"

char flash_buf[SVR_BUFSIZ];

extern FILE *logfp;
extern int mypid;
extern int debug;

/**************************************************************************/

int
passwd_verify_user(user,pass)
char *user;
char *pass;
{
    struct passwd *pwd;
    char *cp;
#ifdef SHADOWPWD
    struct spwd *spwd = NULL;
#endif
    /* DTS added 03July96 to force lower case names */
    for(cp=user; *cp; cp++) { *cp = tolower(*cp); }

    pwd = getpwnam(user);
    if (pwd == NULL) return -1;
    if (pwd->pw_passwd[0] == '!' || !strcmp(pwd->pw_passwd,"*NONE*")) {
        syslog (SYSLOGPRI, "User locked: %s", user);
            return -1;
        }
    if ( !strncmp(pwd->pw_shell,ACCT_SUSP_STR,strlen(ACCT_SUSP_STR))) {
            return -2;
        }
#ifdef SHADOWPWD

    if (pwd && (strlen(pwd->pw_passwd) == 1) ) {
        if (pwd->pw_passwd[0] == 'x' || pwd->pw_passwd[0] == '*') {
            spwd = getspnam(user);
                if (!spwd) {
                    syslog (SYSLOGPRI,
                "No shadow entry for user %s",user);
                    return -1;
                }
                pwd->pw_passwd = spwd->sp_pwdp;
       }
        }
#endif
    if( !strcmp( pwd->pw_passwd, crypt(pass,pwd->pw_passwd)) )
            return(setuid(pwd->pw_uid));
        else
        return(-1);

} /* end passwd_verify_user */

/* Verify a usercode/password */
int
verify_user(user,pass)
char *user;
char *pass;
{
#ifdef TACACS_AUTH
    return( tacacs_verify_user(user,pass) );
/*  #elif VIRTUAL
 *  return( virtual_verify_user(user,pass) );
 */
#else
    return( passwd_verify_user(user,pass) );
#endif
}

char *
fgetl(buf,n,fp)
char *buf;  /* Buffer for text */
int n;      /* Size of buffer */
FILE *fp;   /* Stream to read from */
{
    if (fgets(buf,n,fp) == NULL)
        return(NULL);
    if ((strlen(buf) == (n-1))&&(buf[n-1] != LF_CHAR)) {
        buf[n-1] = LF_CHAR;
        while (fgets(flash_buf,SVR_BUFSIZ,fp) != NULL) {
            if (strlen(flash_buf) != (SVR_BUFSIZ-1))
                break;
            if (flash_buf[SVR_BUFSIZ-1] == LF_CHAR)
                break;
        }
    }
    return(buf);
}

/* Prepare client command for server */
void
cmd_prepare(buf)
char *buf;
{
    char *cp;

    if (buf == NULL)
        return;
    /* Convert command verb to lowercase */
    while (*buf != NULL_CHAR) {
        if (isupper(*buf))
            *buf = tolower(*buf);
        else if (isspace(*buf))
            break;
        ++buf;
    }
    /* Strip trailing whitespace from client command */
    if ((cp = strchr(buf,CR_CHAR)) != NULL) {
        while ((cp != buf)&&(isspace(*cp))) --cp;
        if (!isspace(*cp)) ++cp;
        *cp = NULL_CHAR;
    }
    if ((cp = strchr(buf,LF_CHAR)) != NULL) {
        while ((cp != buf)&&(isspace(*cp))) --cp;
        if (!isspace(*cp)) ++cp;
        *cp = NULL_CHAR;
    }
}

/**************************************************************************/

/* Send an error message and exit POP3 server */
void
fail(err)
int err;
{
    char *cp;

    switch(err) {
    /* DTS 10Oct96 [ 1.005d ] - created error FAIL_DUP_READ */
    case FAIL_DUP_READ:         /* Folder already being read */
        cp = "Folder already being read";
        break;
    case FAIL_FILE_ERROR:           /* File I/O error */
        cp = "File I/O error";
        break;
    case FAIL_HANGUP:           /* Client hung up on us */
        cp = "Lost connection to client";
        break;
    case FAIL_LOST_CLIENT:          /* Timeout waiting for client */
        cp = "Timeout waiting for command from client";
        break;
    case FAIL_OUT_OF_MEMORY:        /* Failed malloc() */
        cp = "Out of memory!";
        break;
    case FAIL_PROGERR:          /* Fatal program error */
        cp = "Fatal program error!";
        break;
    case FAIL_PIPE:             /* Rec'd SIGPIPE - DTS 28Jul96*/
        cp = "Received pipe failure signal!";
        break;
    case FAIL_CONFUSION:            /* Shouldnt happen */
    default:
        cp = "Complete confusion!";
        break;
    }
    fprintf(stdout,"-ERR POP3 Server Abnormal Shutdown: %s\r\n",cp);
    fflush(stdout);
    if ( debug ) {
        fprintf(logfp,"[%d] -ERR POP3 Server Abnormal Shutdown: %s\r\n",mypid,cp);
        fclose(logfp);
    }
    exit(err);              /* Exit with error */
}

/**************************************************************************/

char *
get_fqdn()
{
static char fqdn[SVR_BUFSIZ];
char buff[100];
struct hostent *h;

    if (fqdn[0] != '\0')
        return fqdn;

    if (gethostname(buff, sizeof(buff)) != 0)
    {
        perror("get_fqdn");
        return NULL;
    }

    h = gethostbyname(buff);
    if (!h)
    {
        fprintf(stderr, "get_fqdn: gethostbyname() failed\n");
        return NULL;
    }

    strncpy(fqdn, h->h_name, SVR_BUFSIZ-1);
    return fqdn;
}

/**************************************************************************/