bbspop3d.c

linux下的BBS

/*
 *  Thread BBS POP3 Daemon By [e-mail]
 */

#include <bbs.h>
#include "pop3d.h"

#define CMD_MSG(pop3user, msg)       writeln(pop3user->sockfd,msg);
pthread_t *pop3_thread_lib;
int countpop3user =0;

int
pop3d_client_close (pop3user)
struct pop3cs *pop3user;
{
  int sock;

  if (pop3user->mode >= CM_LOGIN)
    if (pop3user->cache != NULL)
      free (pop3user->cache);
  sock = pop3user->sockfd;
  shutdown (sock, 2);
  close (sock);
  xfree(pop3user);
  countpop3user--;
  pthread_exit (0);
}

int
pop3d_cmd_xxxx (pop3user)
struct pop3cs *pop3user;
{
  CMD_MSG (pop3user, POP3D_ERRCMD_MSG);
}

static char *
parse_token (pop3user, str, lower)
struct pop3cs *pop3user;
char *str;
int lower;
{
  char *token;
  int ch;

  if (str == NULL) {
    str = pop3user->trail_token;
    if (str == NULL)
      return NULL;
  }
  token = NULL;
  while (ch = *str) {
    if (ch == ' ') {
      if (token) {
	*str++ = '\0';
	break;
      }
    } else {
      if (token == NULL)
	token = str;
      if (lower && ch >= 'A' && ch <= 'Z')
	*str = ch | 0x20;
    }
    str++;
  }
  pop3user->trail_token = str;
  return token;
}

int
mbox_open (pop3user)
struct pop3cs *pop3user;
{
  int i = 0;
  char fpath[PATHLEN] = { 0 }, fname[PATHLEN] = {
  0};

  pop3user->pcount = pop3user->pbytes = 0;
  mail_path (pop3user->uid, fpath);
  file_path (fpath, DIR_FILE);
  pop3user->pcount = statf (fpath, F_SIZE) / sizeof (struct dirhead);
  if (pop3user->pcount <= 0)
    return;
  pop3user->cache = (struct dirhead *) calloc (sizeof (struct dirhead), pop3user->pcount);
  get_recs (fpath, pop3user->cache, sizeof (struct dirhead), 0, pop3user->pcount);
  mail_path (pop3user->uid, fpath);
  for (i = 0; i < pop3user->pcount; i++) {
    file_new_path (fname, fpath, pop3user->cache[i].fname);
    pop3user->pbytes = pop3user->pbytes + statf (fname, F_SIZE);
  }
}

int
mbox_read (pop3user, phdr)
struct pop3cs *pop3user;
struct dirhead *phdr;
{
  char fpath[PATHLEN] = { 0 };
  FILE *fp = NULL;
  char buf[512] = { 0 };

  mail_path (pop3user->uid, fpath);
  file_path (fpath, phdr->fname);
  sockprintf (pop3user->sockfd, "+OK %d octets\r\n", statf (fpath, F_SIZE));
  fp = fopen (fpath, "r");
  if (fp != NULL) {
    while (fgets (buf, sizeof (buf), fp) != NULL) {
      if (strncmp (buf, ".\n", 2) == 0) {
	writeln (pop3user->sockfd, "..\r\n");
	memset (buf, 0, sizeof (buf));
	continue;
      }
      if (strncmp (buf, "\n", 1) == 0) {
	writeln (pop3user->sockfd, "\r\n");
	memset (buf, 0, sizeof (buf));
	continue;
      }
      str_tok (buf, "\r\n");
      writeln (pop3user->sockfd, buf);
      writeln (pop3user->sockfd, "\r\n");
      memset (buf, 0, sizeof (buf));
    }
    fclose (fp);
  }
  writeln (pop3user->sockfd, ".\r\n");
}

int
mbox_close (pop3user)
struct pop3cs *pop3user;
{
  int i = 0;
  char dpath[PATHLEN] = { 0 };
  char fpath[PATHLEN] = { 0 };
  char mpath[PATHLEN] = { 0 };

  mail_path (pop3user->uid, mpath);
  file_new_path (dpath, mpath, DIR_FILE);
  for (i = pop3user->pcount; i > 0; i--) {
    if (pop3user->cache[i - 1].mark & HEAD_DELE) {
      file_new_path (fpath, mpath, pop3user->cache[i - 1].fname);
      unlink (fpath);
      del_recs (dpath, sizeof (struct dirhead), i - 1, 1);
    }
  }
}

int
do_argument (pop3user)
struct pop3cs *pop3user;
{
  CMD_MSG (pop3user, POP3D_ERRARG_MSG);
}

int
do_number (pop3user, n)
struct pop3cs *pop3user;
int n;
{
  char *cmd;

  if (pop3user->mode < CM_LOGIN) {
    pop3d_cmd_xxxx (pop3user);
    return 0;
  }
  cmd = parse_token (pop3user, NULL, 0);
  if (!cmd || !*cmd) {
    if (n == 0)
      do_argument (pop3user);
    return n;
  }
  n = atoi (cmd);
  if (n <= 0 || n > pop3user->pcount) {
    CMD_MSG (pop3user, POP3D_ERRNUM_MSG);
    return 0;
  }
  return n;
}

int
pop3d_cmd_noop (pop3user)
struct pop3cs *pop3user;
{
  CMD_MSG (pop3user, POP3D_NOOP_OK);
}

int
pop3d_cmd_user (pop3user)
struct pop3cs *pop3user;
{
  extern struct account *acc;
  char *userid;

  if (pop3user->mode >= CM_LOGIN) {
    pop3d_cmd_xxxx (pop3user);
    return;
  }
  userid = parse_token (pop3user, NULL, 1);
  if (!userid || !*userid) {
    do_argument (pop3user);
    return;
  }
  if (!strstr (userid, ".bbs")) {
    sockprintf (pop3user->sockfd, "-ERR %s has no mail here\r\n", userid);
    return;
  }
  str_tok (userid, ".\r\n");
  if (strlen (userid) > IDLEN) {
    writeln (pop3user->sockfd, POP3D_NOUSER_ERR);
    return;
  }
  if ((pop3user->uid = searchuid (pop3user, userid)) < 0) {
    writeln (pop3user->sockfd, POP3D_NOUSER_ERR);
    return;
  }
  strncpy (pop3user->userid, userid, IDLEN);
  memcpy (pop3user->passwd, acc[pop3user->uid].passwd, PASSLEN);
  sockprintf (pop3user->sockfd, "+OK Password required for %s.bbs\r\n", userid);
}

int
pop3d_cmd_passwd (pop3user)
struct pop3cs *pop3user;
{
  char *cmd;

  if (pop3user->mode >= CM_LOGIN) {
    pop3d_cmd_xxxx (pop3user);
    return;
  }
  if (!*(pop3user->passwd)) {
    CMD_MSG (pop3user, POP3D_NEEDUSER);
    return;
  }
  cmd = pop3user->trail_token;
  if (!cmd || !*cmd) {
    do_argument (pop3user);
    return;
  }
  if (check_bad_uid_ip (pop3user->uid, pop3user->ipaddr)) {
    CMD_MSG (pop3user, POP3D_PASSWD_ERR);
    pop3d_client_close (pop3user);
  }
  if (!chk_passwd (pop3user->passwd, cmd)) {
    *pop3user->passwd = '\0';
    insert_bad_uid_ip (pop3user->uid, pop3user->ipaddr);
    CMD_MSG (pop3user, POP3D_PASSWD_ERR);
    return;
  }
  mbox_open (pop3user);
  sockprintf (pop3user->sockfd, "+OK %s has %d messages (%d octets)\r\n", pop3user->userid, pop3user->pcount, pop3user->pbytes);
  pop3user->mode = CM_LOGIN;
}

int
pop3d_cmd_stat (pop3user)
struct pop3cs *pop3user;
{
  if (pop3user->mode < CM_LOGIN) {
    pop3d_cmd_xxxx (pop3user);
    return;
  }
  sockprintf (pop3user->sockfd, "+OK %d %d\r\n", pop3user->pcount, pop3user->pbytes);
}

int
pop3d_cmd_last (pop3user)
struct pop3cs *pop3user;
{
  if (pop3user->mode < CM_LOGIN) {
    pop3d_cmd_xxxx (pop3user);
    return;
  }
  sockprintf (pop3user->sockfd, "+OK %d\r\n", pop3user->pcount);
}

int
pop3d_cmd_reset (pop3user)
struct pop3cs *pop3user;
{
  int n;

  n = pop3user->mode;
  if (n < CM_LOGIN) {
    pop3d_cmd_xxxx (pop3user);
    return;
  }
  if (n == CM_DIRTY) {
    for (n = 0; n < pop3user->pcount; n++)
      pop3user->cache[n].mark = 0;
  }
  sockprintf (pop3user->sockfd, "+OK mail reset %d messages %d octets\r\n", pop3user->pcount, pop3user->pbytes);
  pop3user->mode = CM_LOGIN;
}

int
pop3d_cmd_retrive (pop3user)
struct pop3cs *pop3user;
{
  int n;

  n = do_number (pop3user, 0);
  if (!n)
    return;
  if (pop3user->cache[n - 1].mark & HEAD_DELE) {
    CMD_MSG (pop3user, POP3D_DELETE_MSG);
    return;
  }
  mbox_read (pop3user, &(pop3user->cache[n - 1]));
}

int
pop3d_cmd_top (pop3user)
struct pop3cs *pop3user;
{
  int n;
  char *cmd;

  n = do_number (pop3user, 0);
  if (!n)
    return;
  if (pop3user->cache[n - 1].mark & HEAD_DELE) {
    CMD_MSG (pop3user, POP3D_DELETE_MSG);
    return;
  }
  cmd = parse_token (pop3user, NULL, 0);
  if (!cmd || !*cmd) {
    do_argument (pop3user);
    return;
  }
  n = atoi (cmd);
  if (n < 0) {
    CMD_MSG (pop3user, POP3D_ERRNUM_MSG);
    return;
  }
  mbox_read (pop3user, &(pop3user->cache[n - 1]));
}

int
pop3d_cmd_delete (pop3user)
struct pop3cs *pop3user;
{
  int n;

  if (!(n = do_number (pop3user, 0)))
    return;
  if (pop3user->cache[n - 1].mark & HEAD_DELE) {
    CMD_MSG (pop3user, POP3D_DELETE_MSG);
    return;
  }
  pop3user->cache[n - 1].mark = HEAD_DELE;
  pop3user->mode = CM_DIRTY;
  CMD_MSG (pop3user, POP3D_DELETE_OK);
}

int
pop3d_cmd_list (pop3user)
struct pop3cs *pop3user;
{
  int n = 0, i = 0;
  char fpath[PATHLEN] = { 0 };

  n = do_number (pop3user, -1);
  if (n < 0) {
    sockprintf (pop3user->sockfd, "+OK %d messages (%d octets)\r\n", pop3user->pcount, pop3user->pbytes);
    for (i = 0; i < pop3user->pcount; i++) {
      mail_path (pop3user->uid, fpath);
      file_path (fpath, pop3user->cache[i].fname);
      sockprintf (pop3user->sockfd, "%d %d\r\n", i + 1, statf (fpath, F_SIZE));
    }
    writeln (pop3user->sockfd, ".\r\n");
  } else if (n > 0) {
    if (pop3user->cache[n - 1].mark & HEAD_DELE) {
      CMD_MSG (pop3user, POP3D_DELETE_MSG);
    } else {
      mail_path (pop3user->uid, fpath);
      file_path (fpath, pop3user->cache[n - 1].fname);
      sockprintf (pop3user->sockfd, "+OK %d %d\r\n", n, statf (fpath, F_SIZE));
    }
  }
}

int
pop3d_cmd_uidl (pop3user)
struct pop3cs *pop3user;
{
  int n, i;

  n = do_number (pop3user, -1);
  if (n < 0) {
    writeln (pop3user->sockfd, POP3D_UIDL_OK);
    for (i = 0; i < pop3user->pcount; i++) {
      sockprintf (pop3user->sockfd, "%d %d.%03d\r\n", i + 1, pop3user->cache[i].time, str_nhash (pop3user->cache[i].msgid, MSGIDLEN, 3) % 1000);
    }
    writeln (pop3user->sockfd, ".\r\n");
  } else if (n > 0) {
    if (pop3user->cache[n - 1].mark & HEAD_DELE) {
      CMD_MSG (pop3user, POP3D_DELETE_MSG);
    } else {
      sockprintf (pop3user->sockfd, "+OK %d %d.%03d", n, pop3user->cache[n - 1].time, str_nhash (pop3user->cache[n - 1].msgid, MSGIDLEN, 3) % 1000);
    }
  }
}

int
pop3d_cmd_quit (pop3user)
struct pop3cs *pop3user;
{
  if (pop3user->mode >= CM_DIRTY) {
    mbox_close (pop3user);
  }
  writeln (pop3user->sockfd, POP3D_BYE_MSG);
  pop3d_client_close (pop3user);
}

int
pop3d_client_serve (pop3user, run)
struct pop3cs *pop3user;
char *run;
{
  char *cmd, *str;
  struct pop3dcmd *pc;

  cmd = parse_token (pop3user, run, 1);
  if (!cmd || !*cmd)
    return;
  for (pc = pop3dcmdlist; str = pc->cmd; pc++) {
    if (!str_ncmp (cmd, str, 4))
      break;
  }
  (*pc->fun) (pop3user);
}

int
pop3d_client_read (pop3user)
struct pop3cs *pop3user;
{
  int cc;
  char buf[RCVBUFSIZ];
  char *str = buf;

  if (!readsock (pop3user->sockfd, str, RCVBUFSIZ)) {
    while (cc = *str) {
      switch (cc) {
	case '\r':
	case '\n':
	  *str = '\0';
	  pop3d_client_serve (pop3user, buf);
	  return 1;
	case '\t':
	  *str = ' ';
      }
      str++;
    }
    pop3d_client_close (pop3user);
  } else {
    pop3d_client_close (pop3user);
  }
}

pop3s (pop3user)
struct pop3cs *pop3user;
{
  int nfds = 0;
  fd_set rset;
  struct timeval tv;

  tv.tv_sec = POP3D_TIMEOUT;
  tv.tv_usec = 0;

  writeln (pop3user->sockfd, POP3D_DAEMON_OK);
  FD_ZERO (&rset);
  FD_SET (pop3user->sockfd, &rset);
  while (1) {
    nfds = select (pop3user->sockfd + 1, &rset, NULL, NULL, &tv);
    if (nfds <= 0) {
      pop3d_client_close (pop3user);
    }
    pop3d_client_read (pop3user);
  }
}

int
pop3d_daemon ()
{
  pthread_attr_t thr_attr;
  struct sockaddr_in from, sin = { AF_INET };
  int bid, sock, on = 1, i = 0, size = 0;
  struct pop3cs *pop3user;

  pop3_thread_lib = calloc (sizeof (pthread_t), MAX_POP3D_CLIENT);
  pop3user = calloc (sizeof (struct pop3cs), MAX_POP3D_CLIENT);
  memset (pop3_thread_lib, 0, sizeof (pthread_t) * MAX_POP3D_CLIENT);
  memset (pop3user, 0, sizeof (struct pop3cs) * MAX_POP3D_CLIENT);
  pthread_attr_init (&thr_attr);
  pthread_attr_setscope (&thr_attr, PTHREAD_SCOPE_SYSTEM);
  pthread_attr_setdetachstate (&thr_attr, PTHREAD_CREATE_DETACHED);
  sin.sin_family = AF_INET;
  sin.sin_addr.s_addr = INADDR_ANY;
  sin.sin_port = htons (POP3_PORT);
  bid = socket (AF_INET, SOCK_STREAM, 0);
  if (bid < 0)
    return (-1);
  setsockopt (bid, SOL_SOCKET, SO_REUSEADDR, (char *) &on, sizeof (on));
  if (bind (bid, (struct sockaddr *) &sin, sizeof (sin)) < 0)
    return (-1);
  if (listen (bid, 20) < 0)
    return (-1);
  for (;;) {
    size = sizeof (from);
    sock = accept (bid, (struct sockaddr *) &from, &size);
    if (sock < 0) {
      bid = socket (AF_INET, SOCK_STREAM, 0);
      setsockopt (bid, SOL_SOCKET, SO_REUSEADDR, (char *) &on, sizeof (on));
      bind (bid, (struct sockaddr *) &sin, sizeof (sin));
      listen (bid, 20);
      continue;
    } else {
      pop3user = malloc (sizeof (struct pop3cs));
      memset (pop3user, 0, sizeof (struct pop3cs));
      pop3user->sockfd = sock;
      if ( ++countpop3user >= MAX_POP3D_CLIENT ) {
		shutdown (sock, 2);
		close(sock);
		xfree(pop3user);
		countpop3user--;
		continue;
      }
      memcpy (pop3user->ipaddr, (char *) inet_ntoa (from.sin_addr), IPLEN);
      pthread_create (&pop3_thread_lib[i], &thr_attr, (void *) pop3s, pop3user);
    }
  }
}