Mercurial > dillo_port1.3
view dpi/ftp.c @ 11:4a5942beffdf
Added some "const" qualifiers.
author | jcid |
---|---|
date | Sun, 14 Oct 2007 04:21:53 +0200 |
parents | 6ee11bf9e3ea |
children | d9e7b35430de |
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/* * 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 catched by dillo who redirects the ftp URL * to the downloads server). * * Feel free to polish! * * Copyright 2003-2005 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 */ #define _MSG(...) #define MSG(...) printf("[ftp dpi]: " __VA_ARGS__) /* * Global variables */ static SockHandler *sh = NULL; 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). */ int a_Misc_get_content_type_from_data(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; size_t i, non_ascci; /* HTML try */ for (i = 0; i < Size && isspace(p[i]); ++i); if ((Size - i >= 5 && !dStrncasecmp(p+i, "<html", 5)) || (Size - i >= 5 && !dStrncasecmp(p+i, "<head", 5)) || (Size - i >= 6 && !dStrncasecmp(p+i, "<title", 6)) || (Size - i >= 14 && !dStrncasecmp(p+i, "<!doctype html", 14)) || /* this line is workaround for FTP through the Squid proxy */ (Size - i >= 17 && !dStrncasecmp(p+i, "<!-- HTML listing", 17))) { Type = 1; st = 0; /* Images */ } else if (Size >= 4 && !dStrncasecmp(p, "GIF8", 4)) { Type = 3; st = 0; } else if (Size >= 4 && !dStrncasecmp(p, "\x89PNG", 4)) { Type = 4; st = 0; } else if (Size >= 2 && !dStrncasecmp(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 * in a 256-bytes sample. Better heuristics are welcomed! :-) */ non_ascci = 0; Size = MIN (Size, 256); for (i = 0; i < Size; i++) if ((uchar_t) p[i] > 127) ++non_ascci; if (Size == 256) { Type = (non_ascci > 10) ? 0 : 2; st = 0; } else { Type = (non_ascci > 0) ? 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. */ static int try_ftp_transfer(char *url) { #define MinSZ 256 ssize_t n; int nb, minibuf_sz; const char *mime_type; char buf[4096], minibuf[MinSZ], *d_cmd; pid_t ch_pid; int aborted = 0; int DataPipe[2]; if (pipe(DataPipe) < 0) { MSG("pipe, %s\n", strerror(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 */ minibuf_sz = 0; for (nb = 0; 1; nb += n) { while ((n = read(DataPipe[0], buf, 4096)) < 0 && errno == EINTR); if (n <= 0) break; if (minibuf_sz < MinSZ) { memcpy(minibuf + minibuf_sz, buf, MIN(n, MinSZ - minibuf_sz)); minibuf_sz += MIN(n, MinSZ - minibuf_sz); if (minibuf_sz < MinSZ) continue; a_Misc_get_content_type_from_data(minibuf, minibuf_sz, &mime_type); 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 */ aborted = 1; } } if (nb == 0) { /* Send dpip tag */ d_cmd = a_Dpip_build_cmd("cmd=%s url=%s", "start_send_page", url); sock_handler_write_str(sh, 1, d_cmd); dFree(d_cmd); /* Send HTTP header. */ sock_handler_write_str(sh, 0, "Content-type: "); sock_handler_write_str(sh, 0, mime_type); sock_handler_write_str(sh, 1, "\n\n"); } if (!aborted) sock_handler_write(sh, 0, buf, n); } return nb; } /* * */ int main(void) { char *dpip_tag = NULL, *cmd = NULL, *url = NULL, *url2 = NULL; int nb; char *p, *d_cmd; /* Initialize the SockHandler */ sh = sock_handler_new(STDIN_FILENO, STDOUT_FILENO, 8*1024); /* wget may need to write a temporary file... */ chdir("/tmp"); /* Read the dpi command from STDIN */ dpip_tag = sock_handler_read(sh); MSG("tag=[%s]\n", dpip_tag); cmd = a_Dpip_get_attr(dpip_tag, strlen(dpip_tag), "cmd"); url = a_Dpip_get_attr(dpip_tag, strlen(dpip_tag), "url"); if (!cmd || !url) { MSG("ERROR, cmd=%s, url=%s\n", cmd, url); exit (EXIT_FAILURE); } if ((nb = try_ftp_transfer(url)) == 0) { /* 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); nb = try_ftp_transfer(url2); } } if (nb == 0) { /* The transfer failed, let dillo know... */ d_cmd = a_Dpip_build_cmd("cmd=%s to_cmd=%s msg=%s", "answer", "open_url", "not a directory"); sock_handler_write_str(sh, 1, d_cmd); dFree(d_cmd); } dFree(cmd); dFree(url); dFree(url2); dFree(dpip_tag); /* Finish the SockHandler */ sock_handler_close(sh); sock_handler_free(sh); return 0; }