ftpclient.c

从busybox提取的ftp客户端程序

/* vi: set sw=4 ts=4: */
/*
 * ftpget
 *
 * Mini implementation of FTP to retrieve a remote file.
 *
 * Copyright (C) 2002 Jeff Angielski, The PTR Group <[e-mail]>
 * Copyright (C) 2002 Glenn McGrath <[e-mail]>
 *
 * Based on wget.c by Chip Rosenthal Covad Communications
 * <[e-mail]>
 *
 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
 */
//#include <ctype.h>
#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <inttypes.h>
#include <mntent.h>
#include <netdb.h>
#include <setjmp.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <stddef.h>
#include <string.h>
#include <strings.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/statfs.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <termios.h>
#include <time.h>
#include <unistd.h>
#include <utime.h>
#include <getopt.h>
#include <limits.h>

#define FTP_HEAD_SIZE 512

/* We hijack this constant to mean something else */
/* It doesn't hurt because we will remove this bit anyway */
#define DIE_ON_ERROR AI_CANONNAME

#define isdigit(a) ((unsigned)((a) - '0') <= 9)

//#define xatou(rest) xatoull##rest

#define LONE_DASH(s)     ((s)[0] == '-' && !(s)[1])

#define NOT_LONE_DASH(s) ((s)[0] != '-' || (s)[1])

#define ENABLE_FEATURE_IPV6 0

#define type long
#define xstrtou(rest) xstrtoul##rest
#define xstrto(rest) xstrtol##rest
#define xatou(rest) xatoul##rest
#define xato(rest) xatol##rest
#define XSTR_UTYPE_MAX ULONG_MAX
#define XSTR_TYPE_MAX LONG_MAX
#define XSTR_TYPE_MIN LONG_MIN
#define XSTR_STRTOU strtoul
#include "ftp_template.c"

#define bb_error_msg_and_die(fmt,args...)	{ \
												printf ("%s( %d): "fmt"\n" ,  __FILE__,__LINE__, ##args); \
												exit(-1); \
											}

#define bb_error_msg(fmt,args...)	printf ("%s( %d): "fmt ,  __FILE__,__LINE__, ##args)

typedef signed char smallint;

typedef struct len_and_sockaddr {
	socklen_t len;
	union {
		struct sockaddr sa;
		struct sockaddr_in sin;
	};
} len_and_sockaddr;

typedef struct ftp_host_info_s {
	const char *user;
	const char *password;
	struct len_and_sockaddr *lsa;
} ftp_host_info_t;


static smallint verbose_flag=1;
static smallint do_continue;

char * safe_strncpy(char *dst, const char *src, size_t size)
{
	if (!size) return dst;
	dst[--size] = '\0';
	return strncpy(dst, src, size);
}


uint16_t xatou16(const char *numstr)
{
	return xatoul_range(numstr, 0, 0xffff);
}

void set_nport(len_and_sockaddr *lsa, unsigned port)
{
	if (lsa->sa.sa_family == AF_INET) 
	{
		lsa->sin.sin_port = port;
		return;
	}
	/* What? UNIX socket? IPX?? :) */
}

void *xmalloc(int size)
{
	void *ptr; 

	ptr = malloc(size);
	if (ptr == NULL && size != 0)
		bb_error_msg_and_die("memory exhausted");
	
	return ptr;
}

static len_and_sockaddr* str2sockaddr(
		const char *host, int port,
		int ai_flags)
{
	int rc;
	len_and_sockaddr *r = NULL;
	struct addrinfo *result = NULL;
	const char *org_host = host; /* only for error msg */
	const char *cp;
	struct addrinfo hint;

	/* Ugly parsing of host:addr */
	if (ENABLE_FEATURE_IPV6 && host[0] == '[') {
		host++;
		cp = strchr(host, ']');
		if (!cp || cp[1] != ':') /* Malformed: must have [xx]:nn */
			bb_error_msg_and_die("bad address '%s'", org_host);
			//return r; /* return NULL */
	} else {
		cp = strrchr(host, ':');
		if (ENABLE_FEATURE_IPV6 && cp && strchr(host, ':') != cp) {
			/* There is more than one ':' (e.g. "::1") */
			cp = NULL; /* it's not a port spec */
		}
	}
	if (cp) {
		int sz = cp - host + 1;
		host = safe_strncpy(alloca(sz), host, sz);
		if (ENABLE_FEATURE_IPV6 && *cp != ':')
			cp++; /* skip ']' */
		cp++; /* skip ':' */
		port = xatou16(cp);
	}

	memset(&hint, 0 , sizeof(hint));
#if !ENABLE_FEATURE_IPV6
	hint.ai_family = AF_INET; /* do not try to find IPv6 */
#else
	hint.ai_family = af;
#endif
	/* Needed. Or else we will get each address thrice (or more)
	 * for each possible socket type (tcp,udp,raw...): */
	hint.ai_socktype = SOCK_STREAM;
	hint.ai_flags = ai_flags & ~DIE_ON_ERROR;
	rc = getaddrinfo(host, NULL, &hint, &result);
	if (rc || !result) {
		bb_error_msg("bad address '%s'", org_host);
		if (ai_flags & DIE_ON_ERROR)
			exit(-1);
		goto ret;
	}
	r = xmalloc(offsetof(len_and_sockaddr, sa) + result->ai_addrlen);
	r->len = result->ai_addrlen;
	memcpy(&r->sa, result->ai_addr, result->ai_addrlen);
	set_nport(r, htons(port));
 ret:
	freeaddrinfo(result);
	return r;
}


int xsocket(int nDomain, int nType, int nProtocol)
{
	int r;

	r = socket(nDomain, nType, nProtocol);

	if (r < 0) {
		/* Hijack vaguely related config option */

		bb_error_msg_and_die("socket");

	}

	return r;
}

void xconnect(int s, const struct sockaddr *s_addr, socklen_t addrlen)
{
	if (connect(s, s_addr, addrlen) < 0) 
	{
		close(s);
		if (s_addr->sa_family == AF_INET)
			bb_error_msg_and_die("%s (%s)",
				"cannot connect to remote host",
				inet_ntoa(((struct sockaddr_in *)s_addr)->sin_addr));
		//bb_error_msg_and_die("cannot connect to remote host");
	}
}

int xconnect_stream(const len_and_sockaddr *lsa)
{
	int fd = xsocket(lsa->sa.sa_family, SOCK_STREAM, 0);
	xconnect(fd, &lsa->sa, lsa->len);
	return fd;
}

int xopen(const char *pathname, int flags, int mode)
{
	int ret;

	ret = open(pathname, flags, mode);
	if (ret < 0) {
		bb_error_msg_and_die("can't open '%s'", pathname);
	}
	return ret;
}

ssize_t safe_read(int fd, void *buf, size_t count)
{
	ssize_t n;

	do {
		n = read(fd, buf, count);
	} while (n < 0 && errno == EINTR);

	return n;
}

ssize_t safe_write(int fd, const void *buf, size_t count)
{
	ssize_t n;

	do {
		n = write(fd, buf, count);
	} while (n < 0 && errno == EINTR);

	return n;
}


/*
 * Write all of the supplied buffer out to a file.
 * This does multiple writes as necessary.
 * Returns the amount written, or -1 on an error.
 */
ssize_t full_write(int fd, const void *buf, size_t len)
{
	ssize_t cc;
	ssize_t total;

	total = 0;

	while (len) {
		cc = safe_write(fd, buf, len);

		if (cc < 0)
			return cc;	/* write() returns -1 on failure. */

		total += cc;
		buf = ((const char *)buf) + cc;
		len -= cc;
	}

	return total;
}

static off_t bb_full_fd_action(int src_fd, int dst_fd, off_t size)
{
	int status = -1;
	off_t total = 0;
	char buffer[BUFSIZ];

	if (src_fd < 0)
		goto out;

	if (!size) {
		size = BUFSIZ;
		status = 1; /* copy until eof */
	}

	while (1) {
		ssize_t rd;

		rd = safe_read(src_fd, buffer, size > BUFSIZ ? BUFSIZ : size);
//printf("-----rd =%d----\n", rd);
		if (!rd) { /* eof - all done */
			status = 0;
			break;
		}
		if (rd < 0) {
			//bb_error_msg(bb_msg_read_error);
			break;
		}
		/* dst_fd == -1 is a fake, else... */
		if (dst_fd >= 0) {
			ssize_t wr = full_write(dst_fd, buffer, rd);
			if (wr < rd) {
				//bb_error_msg(bb_msg_write_error);
				break;
			}
		}
		total += rd;
		if (status < 0) { /* if we aren't copying till EOF... */
			size -= rd;
			if (!size) {
				/* 'size' bytes copied - all done */
				status = 0;
				break;
			}
		}
	}
 out:
	return status ? -1 : total;
}


off_t bb_copyfd_size(int fd1, int fd2, off_t size)
{
	if (size) {
		return bb_full_fd_action(fd1, fd2, size);
	}
	return 0;
}

off_t bb_copyfd_eof(int fd1, int fd2)
{
	return bb_full_fd_action(fd1, fd2, 0);
}

static void ftp_die(const char *msg, const char *remote)
{
	/* Guard against garbage from remote server */
	const char *cp = remote;
	while (*cp >= ' ' && *cp < '\x7f') cp++;
	bb_error_msg_and_die("unexpected server response%s%s: %.*s",
			msg ? " to " : "", msg ? msg : "",
			(int)(cp - remote), remote);
	exit(-1);
}


static int ftpcmd(const char *s1, const char *s2, FILE *stream, char *buf)
{
	unsigned n;
	if (verbose_flag) {
		bb_error_msg("cmd %s %s", s1, s2);
	}

	if (s1) {
		if (s2) {
			fprintf(stream, "%s %s\r\n", s1, s2);
		} else {
			fprintf(stream, "%s\r\n", s1);
		}
	}
	do {
		char *buf_ptr;

		if (fgets(buf, 510, stream) == NULL) {
			bb_error_msg_and_die("fgets");
		}

		buf_ptr = strstr(buf, "\r\n");
		if (buf_ptr) {
			*buf_ptr = '\0';
			printf("--%s\n", buf);
		}
	} while (!isdigit(buf[0]) || buf[3] != ' ');

	buf[3] = '\0';
	//n = xatou(buf);
	n = atol(buf);
	buf[3] = ' ';
	return n;
}

static int xconnect_ftpdata(ftp_host_info_t *server, char *buf)
{
	char *buf_ptr;
	unsigned short port_num;

	/* Response is "NNN garbageN1,N2,N3,N4,P1,P2[)garbage]
	 * Server's IP is N1.N2.N3.N4 (we ignore it)
	 * Server's port for data connection is P1*256+P2 */
	buf_ptr = strrchr(buf, ')');
	if (buf_ptr) *buf_ptr = '\0';

	buf_ptr = strrchr(buf, ',');
	*buf_ptr = '\0';
	port_num = xatoul_range(buf_ptr + 1, 0, 255);

	buf_ptr = strrchr(buf, ',');
	*buf_ptr = '\0';
	port_num += xatoul_range(buf_ptr + 1, 0, 255) * 256;

	set_nport(server->lsa, htons(port_num));
	return xconnect_stream(server->lsa);