nap.c

P2P NAP的C实现 P2P在网络应用中越来越流行

/* Copyright (c) 2000  Kevin Sullivan <[e-mail]>
 *
 * Please refer to the COPYRIGHT file for more information.
 */

#ifdef HAVE_CONFIG_H
# include <config.h>
#endif

#define _GNU_SOURCE /* needed for stdio.h:vasprintf */
#include <stdio.h>
#include <time.h>
#include <stdarg.h>
#include <termios.h>
#include <dirent.h>
#include <fcntl.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <sys/wait.h>
#include <utime.h>
#include <ncurses.h>
#include <stdlib.h>
#include <signal.h>
#include <string.h>
#include <ctype.h>
#include <unistd.h>
#include <sys/stat.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <sys/time.h>
#include <netdb.h>
#include <errno.h>

#include "getopt.h"
#include "defines.h"
#include "codes.h"
#include "colors.h"
#include "title.h"
#include "alias.h"
#include "event.h"
#include "handlers.h"
#include "lists.h"
#include "nap.h"
#include "scheck.h"
#include "winio.h"
#include "missing.h"

#ifdef MEMWATCH
  #include "memwatch.h"
#endif

/* standard napster servers */

extern int ircin;
extern int ircsock;
extern int ups[], speeds[];
extern char cbuf[];
extern upload_t *up;
extern download_t *down;

chans_t *chanl = NULL, *curchan = NULL;
hotlist_t *hlist = NULL;
info_t info;          /* struct to hold some command line options */
int cloaked = 0;      /* whether we are cloaked */
int lpbrk=0, noresolv=0, reconnect=0;
int ipcs[2];
int dresize = 0;

void doquit()
{
  scrollbottom();
  if (wchan)
  {
    dscr(wchan);
    drw(wchan);
  }
  if (ircin)
  {
    ssock(ircsock, "QUIT :Leaving\n");
    close(ircsock);
    ircsock = 0;
  }
  if (nvar_default("savechannels", 0)) {
    char *tmp = NULL, *fn;
    msprintf(&tmp, CHANNELFILE, info.user);
    fn = home_file(tmp);
    free(tmp);

    if (savechans(chanl, fn)==-1) {
      wp(wchan, ""RED"* Could not save channels to %s: %s"WHITE"\n", fn, \
	 strerror(errno));
    } else {
      wp(wchan, "* Saved channels to %s\n", fn);
    }
    free(fn);
  }

  /* close incomplete files, remove turds, etc */
  while (up)
    dupload(up);
  while (down)
    ddownload(wchan, down);
  endwin();

  exit(1);
}

void tresize(int dummy)
{
  dresize = 1;
}

/* catch interrupt signal, i.e. usually "Control-C". In interactive
   mode, quit program only after receiving two interrupts within one
   second. Interrupt also causes a "while" loop to be broken - see
   dwhile in cmds.c */

void sigint(int dummy)
{
  int save_errno = errno;
  static time_t cct = 0;

  if ((time(NULL)-cct) <= 1)
    doquit();
  
  cct = time(NULL);
  lpbrk = 1;
  errno = save_errno;
}

/* the following is used as a signal "handler" if we just want the
   signal to cause a side effect, such as interrupting sleep(3) */
void noop(int dummy)
{
  /* empty */
}

/* handle the USR1 signal. This should schedule the "reconnect" command. */

void sigusr1(int dummy)
{
  reconnect = 1;
}  

void dochecks()
{
  if (dresize)
  {
    dresize = 0;
    resize();
  }
}

/* quotes a string so that it is printable. Each call frees the
   previously returned value. */
char *quote(char *s) {
  static char *buf = NULL;
  int i, size;

  if (buf) {
    free(buf);
  }

  size = strlen(s) * 1.2;

  buf = (char *)malloc(size);

  for (i=0; *s != 0; s++) {
    if (i>size-10) {
      size += 100;
      buf = (char *)realloc(buf, size);
    }
    if (32 <= *s && *s < 127) { /* printable ASCII */
      buf[i++] = *s;
    } else if (*s == '\n') {
      i += sprintf(&buf[i], "\\n");
    } else if (*s == '\r') {
      i += sprintf(&buf[i], "\\r");
    } else {
      i += sprintf(&buf[i], "\\%03o", (unsigned char)*s);
    }
  }
  buf[i] = 0;
  return buf;
}

/* returns the full path of file fn relative to user's home
   directory. Always returns an allocated string. */
char *home_file(const char *fn) {
  char *home, *res;
  int len;

  if (fn[0] == '/')         /* absolute filename? */
    return strdup(fn);

  if (0==strncmp(fn,"~/",2))   /* handle also ~/ syntax - dz */
    fn += 2;

  home = getenv("HOME");   /* else, try to find home directory */
  if (!home)
    return strdup(fn);

  len = strlen(home);
  res = (char *)malloc(len+strlen(fn)+2);
  strcpy(res, home);
  if (home[len-1] != '/')
    strcat(res, "/");
  strcat(res, fn);
  return res;
}

/* make a an allocated string from an integer, similar to strdup */
char *itoa(int n) {
  char buf[20];

  sprintf(buf, "%d", n);
  return strdup(buf);
}

/* strip whitespace from both ends of a string, descructively */
char *strip(char *s) {
  char *p;

  if (!s)
    return NULL;

  while (isspace(*s)) {
    s++;
  }

  p = s+strlen(s);
  while (p>s && isspace(p[-1]))
    p--;
  *p = 0;
  return s;
}

/* read an allocated, stripped line from stream. Return NULL on eof or
   error. */

char *nap_getline(FILE *f) {
  char *buf;
  char *res;
  int size;     /* current allocated size of buf */
  int l;
  size = 200;   /* should be large enough to hold an average line from
		 * the shared library without having to realloc() the
		 * buffer */

  buf = (char *)malloc(size);

  res = fgets(buf, size, f);
  if (!res) {          /* end of file */
    free(buf);
    return NULL;
  }
  while (!strchr(buf, '\n')) {
    size *= 2;
    buf = (char *)realloc(buf, size);
    l = strlen(buf);
    res = fgets(buf+l, size-l, f);
    if (!res)          /* end of file */
      break;
  }

  /* strip whitespace from both ends */
  res = strdup(strip(buf));
  free(buf);
  return res;
}

/* Read the config file FN. Values that were given on the command line
   override those in the config file - don't read them. Note: if user
   was specified on the command line, take special care *not* to use
   password and email address from config file. FN must be a non-null
   filename. Return 0. */

int readcfg(char *fn) {
  int other_user = 0;
  char *user=NULL, *pass=NULL, *email=NULL;
  int r;
  struct stat st;
  char *gfn;

  if (getval("user")) { /* user was specified on command line - do not
                           use password or email from config file */
    other_user = 1;
    user = strdup(getval("user"));
    pass = getrealval("pass");
    if (pass)
      pass = strdup(pass);
    email = getval("email");
    if (email)
      email = strdup(email);
  }
  
  /* read the config file - but in a wimpy way that does not overwrite
     existing values. This is because command line values should have
     priority. */
  wp(NULL, "Reading user config file %s...\n", fn);
  r = loadsets(fn, NULL, 0, 0);

  if (r==0) {
    /* success */
  } else if (r==1) {
    wp(NULL, "There were some warnings, please edit your config file.\n");
  } else if (errno == ENOENT) {   /* no such file or directory */
    wp(NULL, "%s: file not found.\n", fn);
  } else {
    wp(NULL, "Error loading config file %s: %s\n", fn, strerror(errno));
  }

  /* read the global config file, if any. Note that this is read
     *last*. I.e., the values given there are the *least*
     authoritative. */

  gfn = getval("globalconfigfile");
  if (!gfn) {
    gfn = GLOBALCONFIGFILE;
  }

  if (gfn) {
    r = stat(gfn, &st);
    if (r==0 && S_ISREG(st.st_mode)) { /* only if file exists and is regular */
      
      wp(NULL, "Reading global config file %s...\n", gfn);
      r = loadsets(gfn, NULL, 0, 0);
      
      if (r==0) {
	/* success */
      } else if (r==1) {
	wp(NULL, "There were some warnings, please edit global config file.\n");
      } else if (errno == ENOENT) {   /* no such file or directory */
	wp(NULL, "%s: file not found.\n", gfn);
      } else {
	wp(NULL, "Error loading global config file %s: %s\n", gfn, strerror(errno));
      }
    }
  }

  /* restore password and email if necessary */
  if (other_user) {
    chset("user", user);
    chset("pass", pass);
    chset("email", email);
    free(user);
    free(pass);
    free(email);
  }
  
  return 0;
}

/* Try to guess reasonable defaults for vital configuration variables.
   Where appropriate, prompt the user. Return -1 if the user refused
   to supply a username or password, else 0. FN must be a non-null
   filename for the config file to be created / updated. If FN is
   null, nothing will be written to a file. Note: if info.daemon is
   set, then we never prompt the user for anything, and supply
   defaults as we can. */

int set_defaults_interactive(char *fn) {
  int changes = 0;
  char *ans;
  char *user, *pass;
  int conn;
  int r;
  struct stat st;
  int userprompt = 0;

  ans = NULL;

  if (!getval("user")) {
    if (!info.daemon) {
      userprompt = 1;
      wp(NULL, "User: ");
      ans = nap_getline(stdin);
    }
    if (!ans || !*ans) {
      wp(NULL, "No user name given\n");
      free(ans);
      return(-1);
    } else {
      chset("user", ans);
      changes = 1;
    }
  }

  free(ans);
  ans = NULL;

  user = getval("user");
  pass = getrealval("pass"); /* note: getval("pass") does not work - it always
				returns "?" */

  /* if password not defined, check the variable pass.<user> */
  if (!pass || !strcmp(pass, "?")) {
    char tmp[10+strlen(user)];
    strcpy(tmp, "pass.");
    strcat(tmp, user);
    pass = getval(tmp);
    if (pass) {
      chset("pass", pass);
    }
  }

  if (!pass || !strcmp(pass,"?")) {
    if (userprompt) {
      wp(NULL, "Password for user %s (optional): ", user);
      ans = getpass(""); /* note: getpass(3) does not allocate its
                            result value, thus we should not free it. */
    }
    if (ans && *ans) {
      chset("pass", ans);
    }
  }
  ans = NULL;
  
  pass = getrealval("pass");
  if (!pass || !strcmp(pass, "?")) {
    char pw[9];
    struct timeval tv;
    int i;
    
    gettimeofday(&tv, NULL);
    srand(tv.tv_usec + 1000000*tv.tv_sec);
    for (i=0; i<8; i++) {
      pw[i] = rand() % 26 + 'a';
    }
    pw[8] = 0;
    chset("pass", pw);
    wp(NULL, "No password given - using random password\n");
  }

  /* if email not defined, check the variable email.<user> */
  if (!getval("email")) {
    char *email;
    char tmp[10+strlen(user)];
    strcpy(tmp, "email.");
    strcat(tmp, user);
    email = getval(tmp);
    if (email) {
      chset("email", email);
    }
  }

  if (!getval("email")) {
    if (userprompt) {
      wp(NULL, "Email for user %s (optional): ", user);
      ans = nap_getline(stdin);
    }
    if (ans && *ans) {
      chset("email", ans);
      changes = 1;
    }
    free(ans);
    ans = NULL;
  }
  
  if (!getval("email")) {
    chset("email", "anon@localhost");
    wp(NULL, "No email given - using anon@localhost\n");
  }

  if (!getval("upload")) {
    if (!info.daemon) {
      wp(NULL, "Please enter a list of directories with files that you want to share.\n");
      wp(NULL, "You can enter several directories, separated by semicolons (';').\n");
      wp(NULL, "Upload path: ");
      ans = nap_getline(stdin);
    }
    if (!ans || !*ans) {
      wp(NULL, "No upload directories given - unable to share files\n");
    } else {
      chset("upload", ans);
      changes = 1;
    }
  }

  free(ans);
  ans = NULL;

  if (!getval("download")) {
    if (!info.daemon) {
      wp(NULL, "Please enter the directory where you want to put downloaded files.\n");
      wp(NULL, "Download directory: ");
      ans = nap_getline(stdin);
    }
    if (!ans || !*ans) {
      wp(NULL, "No download directory given - will use current working directory\n");
    } else {
      chset("download", ans);
      changes = 1;
    }
  }

  free(ans);
  ans = NULL;

  if (!getval("incomplete")) {
    if (!info.daemon) {
      wp(NULL, "Please enter the directory where you want to put incomplete files.\n");
      wp(NULL, "Incomplete directory: ");
      ans = nap_getline(stdin);
    }
    if (!ans || !*ans) {
      wp(NULL, "No incomplete directory given - will use download directory\n");
    } else {
      chset("incomplete", ans);
      changes = 1;
    }
  }

  free(ans);
  ans = NULL;

  if (!getval("dataport")) {
    if (!info.daemon) {
      wp(NULL, "Are you behind a firewall? [y=yes, n=no, u=unsure]: ");
      ans = nap_getline(stdin);
      if (ans && ans[0]=='y') {
	wp(NULL, "Firewalled client - setting dataport to 0\n");
	chset("dataport", "0");
      } else if (ans && ans[0]=='n') {
	wp(NULL, "Using dataport 6699-6799\n");
	chset("dataport", "6699-6799");
      } else {
	wp(NULL, "Okay, I will assume that you are not firewalled. If you\n"
	   "find out later that you are, please set your dataport to 0.\n");
	wp(NULL, "Using dataport 6699-6799\n");
	chset("dataport", "6699-6799");
      }
    } else {
      chset("dataport", "6699-6799");
      wp(NULL, "No dataport given - using %s\n", getval("dataport"));
    }
  }

  free(ans);
  ans = NULL;

  if (!getval("connection")) {
    if (!info.daemon) {
      wp(NULL, 
	 "          Connection | Number\n"
	 "          -------------------\n"
	 "          Unknown    |  0\n"
	 "          14.4       |  1\n"
	 "          28.8       |  2\n"
	 "          33.6       |  3\n"
	 "          56.7       |  4\n"
	 "          64K ISDN   |  5\n"
	 "          128K ISDN  |  6\n"
	 "          Cable      |  7\n"
	 "          DSL        |  8\n"
	 "          T1         |  9\n"
	 "          T3 or >    | 10\n"
	 );
      wp(NULL, "How fast is your internet connection?\n");
      wp(NULL, "Please choose 0--10 from the chart: [4] ");
      ans = nap_getline(stdin);
    }
    if (!ans || !*ans) {
      chset("connection", "4");
      changes = 1;
    } else {
      chset("connection", ans);