/*
* Dpi for FTP.
*
* This server checks the ftp-URL to be a directory (requires wget).
* If true, it sends back an html representation of it, and if not
* a dpip message (which is caught by dillo who redirects the ftp URL
* to the downloads server).
*
* Feel free to polish!
*
* Copyright 2003-2007 Jorge Arellano Cid <jcid@dillo.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3 of the License, or
* (at your option) any later version.
*
*/
/*
* TODO:
* - Send feedback about the FTP login process from wget's stderr.
* i.e. capture our child's stderr, process it, and report back.
* - Handle simultaneous connections.
* If ftp.dpi is implemented with a low level ftp library, it becomes
* possible to keep the connection alive, and thus make browsing of ftp
* directories faster (this avoids one login per page, and forks). Perhaps
* it's not worth, but can be done.
*/
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <signal.h>
#include <sys/wait.h>
#include <errno.h>
#include <sys/time.h>
#include <ctype.h>
#include "../dpip/dpip.h"
#include "dpiutil.h"
#include "d_size.h"
/*
* Debugging macros
* (Set debugging messages to stderr, to see them)
*/
#define _MSG(...)
//#define MSG(...) fprintf(stderr, "[ftp dpi]: " __VA_ARGS__)
#define MSG(...) printf("[ftp dpi]: " __VA_ARGS__)
/*
* Global variables
*/
static Dsh *sh = NULL;
static char **dl_argv = NULL;
/*---------------------------------------------------------------------------*/
/* TODO: could use dStr ADT! */
typedef struct ContentType_ {
const char *str;
int len;
} ContentType_t;
static const ContentType_t MimeTypes[] = {
{ "application/octet-stream", 24 },
{ "text/html", 9 },
{ "text/plain", 10 },
{ "image/gif", 9 },
{ "image/png", 9 },
{ "image/jpeg", 10 },
{ NULL, 0 }
};
/*
* Detects 'Content-Type' from a data stream sample.
*
* It uses the magic(5) logic from file(1). Currently, it
* only checks the few mime types that Dillo supports.
*
* 'Data' is a pointer to the first bytes of the raw data.
*
* Return value: (0 on success, 1 on doubt, 2 on lack of data).
*/
static int a_Misc_get_content_type_from_data2(void *Data, size_t Size,
const char **PT)
{
int st = 1; /* default to "doubt' */
int Type = 0; /* default to "application/octet-stream" */
char *p = Data;
uchar_t ch;
size_t i, non_ascci;
/* HTML try */
for (i = 0; i < Size && dIsspace(p[i]); ++i);
if ((Size - i >= 5 && !dStrnAsciiCasecmp(p+i, "<html", 5)) ||
(Size - i >= 5 && !dStrnAsciiCasecmp(p+i, "<head", 5)) ||
(Size - i >= 6 && !dStrnAsciiCasecmp(p+i, "<title", 6)) ||
(Size - i >= 14 && !dStrnAsciiCasecmp(p+i, "<!doctype html", 14)) ||
/* this line is workaround for FTP through the Squid proxy */
(Size - i >= 17 && !dStrnAsciiCasecmp(p+i, "<!-- HTML listing", 17))) {
Type = 1;
st = 0;
/* Images */
} else if (Size >= 4 && !strncmp(p, "GIF8", 4)) {
Type = 3;
st = 0;
} else if (Size >= 4 && !strncmp(p, "\x89PNG", 4)) {
Type = 4;
st = 0;
} else if (Size >= 2 && !strncmp(p, "\xff\xd8", 2)) {
/* JPEG has the first 2 bytes set to 0xffd8 in BigEndian - looking
* at the character representation should be machine independent. */
Type = 5;
st = 0;
/* Text */
} else {
/* We'll assume "text/plain" if the set of chars above 127 is <= 10%
* of the sample. This helps to catch ASCII, LATIN1 and UTF-8 as text.
* Better heuristics are welcomed! :-) */
non_ascci = 0;
Size = MIN (Size, 256);
for (i = 0; i < Size; i++) {
ch = (uchar_t) p[i];
if ((ch < 32 || ch > 126) && !dIsspace(ch))
++non_ascci;
}
if (Size == 256) {
Type = (non_ascci > Size/10) ? 0 : 2;
st = 0;
} else {
Type = (non_ascci > Size/10) ? 0 : 2;
}
}
*PT = MimeTypes[Type].str;
return st;
}
/*---------------------------------------------------------------------------*/
/*
* Build a shell command using wget for this URL.
*/
static void make_wget_argv(char *url)
{
char *esc_url;
if (dl_argv) {
dFree(dl_argv[2]);
dFree(dl_argv);
}
dl_argv = dNew(char*, 10);
esc_url = Escape_uri_str(url, "'");
/* avoid malicious SMTP relaying with FTP urls */
Filter_smtp_hack(esc_url);
dl_argv[0] = "wget";
dl_argv[1] = "-O-";
dl_argv[2] = esc_url;
dl_argv[3] = NULL;
}
/*
* Fork, exec command, get its output and send via stdout.
* Return: Number of bytes transfered, -1 if file-not_found, -2 if aborted.
*/
static int try_ftp_transfer(char *url)
{
#define MIN_SZ 256
#define READ_SZ 16*1024
ssize_t n;
int nb, has_mime_type, has_html_header, no_such_file, offer_download;
const char *mime_type = "application/octet-stream";
char buf[READ_SZ], *d_cmd;
Dstr *dbuf = dStr_sized_new(READ_SZ);
pid_t ch_pid;
int aborted = 0;
int DataPipe[2];
if (pipe(DataPipe) < 0) {
MSG("pipe, %s\n", dStrerror(errno));
return 0;
}
/* Prepare args for execvp() */
make_wget_argv(url);
/* Start the child process */
if ((ch_pid = fork()) == 0) {
/* child */
/* start wget */
close(DataPipe[0]);
dup2(DataPipe[1], 1); /* stdout */
execvp(dl_argv[0], dl_argv);
_exit(1);
} else if (ch_pid < 0) {
perror("fork, ");
exit(1);
} else {
/* father continues below */
close(DataPipe[1]);
}
/* Read/Write the real data */
nb = 0;
has_mime_type = 0;
has_html_header = 0;
no_such_file = 0;
offer_download = 0;
do {
while ((n = read(DataPipe[0], buf, READ_SZ)) < 0 && errno == EINTR);
if (n > 0) {
dStr_append_l(dbuf, buf, n);
if (!has_mime_type && dbuf->len < MIN_SZ)
continue;
} else if (n < 0)
break;
if (!has_mime_type) {
if (dbuf->len == 0) {
/* When the file doesn't exist, the transfer size is zero */
no_such_file = 1;
break;
}
a_Misc_get_content_type_from_data2(dbuf->str, dbuf->len, &mime_type);
has_mime_type = 1;
if (strcmp(mime_type, "application/octet-stream") == 0) {
/* abort transfer */
kill(ch_pid, SIGTERM);
/* The "application/octet-stream" MIME type will be sent and
* Dillo will offer a download dialog */
offer_download = 1;
aborted = 1;
}
}
if (offer_download || (!aborted && !has_html_header && dbuf->len)) {
/* Send dpip tag */
d_cmd = a_Dpip_build_cmd("cmd=%s url=%s", "start_send_page", url);
a_Dpip_dsh_write_str(sh, 1, d_cmd);
dFree(d_cmd);
/* Send HTTP header. */
a_Dpip_dsh_write_str(sh, 0, "Content-type: ");
a_Dpip_dsh_write_str(sh, 0, mime_type);
a_Dpip_dsh_write_str(sh, 1, "\r\n\r\n");
has_html_header = 1;
}
if (!aborted && dbuf->len) {
a_Dpip_dsh_write(sh, 1, dbuf->str, dbuf->len);
nb += dbuf->len;
dStr_truncate(dbuf, 0);
}
} while (n > 0 && !aborted);
dStr_free(dbuf, 1);
return (no_such_file ? -1 : (aborted ? -2 : nb));
}
/*
*
*/
int main(int argc, char **argv)
{
const char *err_msg = "404 Not Found\nNo such file or directory";
char *dpip_tag = NULL, *cmd = NULL, *url = NULL, *url2 = NULL;
int st, rc;
char *p, *d_cmd;
/* wget may need to write a temporary file... */
rc = chdir("/tmp");
if (rc == -1) {
MSG("paths: error changing directory to /tmp: %s\n",
dStrerror(errno));
}
/* Initialize the SockHandler */
sh = a_Dpip_dsh_new(STDIN_FILENO, STDOUT_FILENO, 8*1024);
if (argc == 2) {
/* Debugging with a command line argument */
dpip_tag = dStrdup(argv[1]);
} else {
/* Authenticate our client... */
if (!(dpip_tag = a_Dpip_dsh_read_token(sh, 1)) ||
a_Dpip_check_auth(dpip_tag) < 0) {
MSG("can't authenticate request: %s\n", dStrerror(errno));
a_Dpip_dsh_close(sh);
return 1;
}
dFree(dpip_tag);
/* Read the dpi command from STDIN */
dpip_tag = a_Dpip_dsh_read_token(sh, 1);
}
MSG("tag=[%s]\n", dpip_tag);
cmd = a_Dpip_get_attr(dpip_tag, "cmd");
url = a_Dpip_get_attr(dpip_tag, "url");
if (!cmd || !url) {
MSG("ERROR, cmd=%s, url=%s\n", cmd, url);
exit (EXIT_FAILURE);
}
if ((st = try_ftp_transfer(url)) == -1) {
/* Transfer failed, the requested file may not exist or be a symlink
* to a directory. Try again... */
if ((p = strrchr(url, '/')) && p[1]) {
url2 = dStrconcat(url, "/", NULL);
st = try_ftp_transfer(url2);
}
}
if (st == -1) {
/* The transfer failed, let dillo know... */
d_cmd = a_Dpip_build_cmd("cmd=%s url=%s", "start_send_page", url);
a_Dpip_dsh_write_str(sh, 0, d_cmd);
dFree(d_cmd);
a_Dpip_dsh_printf(sh, 1,
"HTTP/1.1 404 Not Found\r\n"
"Content-Type: text/plain\r\n"
"Content-Length: %d\r\n"
"\r\n"
"%s",
strlen(err_msg), err_msg);
}
dFree(cmd);
dFree(url);
dFree(url2);
dFree(dpip_tag);
/* Finish the SockHandler */
a_Dpip_dsh_close(sh);
a_Dpip_dsh_free(sh);
return 0;
}