busybox/mailutils/mail.c

/* vi: set sw=4 ts=4: */
/*
 * helper routines
 *
 * Copyright (C) 2008 by Vladimir Dronnikov <dronnikov@gmail.com>
 *
 * Licensed under GPLv2, see file LICENSE in this tarball for details.
 */
#include "libbb.h"
#include "mail.h"

static void kill_helper(void)
{
	// TODO!!!: is there more elegant way to terminate child on program failure?
	if (G.helper_pid > 0)
		kill(G.helper_pid, SIGTERM);
}

// generic signal handler
static void signal_handler(int signo)
{
#define err signo
	if (SIGALRM == signo) {
		kill_helper();
		bb_error_msg_and_die("timed out");
	}

	// SIGCHLD. reap zombies
	if (safe_waitpid(G.helper_pid, &err, WNOHANG) > 0)
		if (WIFEXITED(err)) {
			G.helper_pid = 0;
			if (WEXITSTATUS(err))
				bb_error_msg_and_die("child exited (%d)", WEXITSTATUS(err));
		}
#undef err
}

void FAST_FUNC launch_helper(const char **argv)
{
	// setup vanilla unidirectional pipes interchange
	int idx;
	int pipes[4];

	xpipe(pipes);
	xpipe(pipes+2);
	G.helper_pid = vfork();
	if (G.helper_pid < 0)
		bb_perror_msg_and_die("vfork");
	idx = (!G.helper_pid) * 2;
	xdup2(pipes[idx], STDIN_FILENO);
	xdup2(pipes[3-idx], STDOUT_FILENO);
	if (ENABLE_FEATURE_CLEAN_UP)
		for (int i = 4; --i >= 0; )
			if (pipes[i] > STDOUT_FILENO)
				close(pipes[i]);
	if (!G.helper_pid) {
		// child: try to execute connection helper
		BB_EXECVP(*argv, (char **)argv);
		_exit(127);
	}
	// parent: check whether child is alive
	bb_signals(0
		+ (1 << SIGCHLD)
		+ (1 << SIGALRM)
		, signal_handler);
	signal_handler(SIGCHLD);
	// child seems OK -> parent goes on
	atexit(kill_helper);
}

const FAST_FUNC char *command(const char *fmt, const char *param)
{
	const char *msg = fmt;
	if (timeout)
		alarm(timeout);
	if (msg) {
		msg = xasprintf(fmt, param);
		printf("%s\r\n", msg);
	}
	fflush(stdout);
	return msg;
}

// NB: parse_url can modify url[] (despite const), but only if '@' is there
/*
static char FAST_FUNC *parse_url(char *url, char **user, char **pass)
{
	// parse [user[:pass]@]host
	// return host
	char *s = strchr(url, '@');
	*user = *pass = NULL;
	if (s) {
		*s++ = '\0';
		*user = url;
		url = s;
		s = strchr(*user, ':');
		if (s) {
			*s++ = '\0';
			*pass = s;
		}
	}
	return url;
}
*/

void FAST_FUNC encode_base64(char *fname, const char *text, const char *eol)
{
	enum {
		SRC_BUF_SIZE = 45,  /* This *MUST* be a multiple of 3 */
		DST_BUF_SIZE = 4 * ((SRC_BUF_SIZE + 2) / 3),
	};

#define src_buf text
	FILE *fp = fp;
	ssize_t len = len;
	char dst_buf[DST_BUF_SIZE + 1];

	if (fname) {
		fp = (NOT_LONE_DASH(fname)) ? xfopen_for_read(fname) : (FILE *)text;
		src_buf = bb_common_bufsiz1;
	// N.B. strlen(NULL) segfaults!
	} else if (text) {
		// though we do not call uuencode(NULL, NULL) explicitly
		// still we do not want to break things suddenly
		len = strlen(text);
	} else
		return;

	while (1) {
		size_t size;
		if (fname) {
			size = fread((char *)src_buf, 1, SRC_BUF_SIZE, fp);
			if ((ssize_t)size < 0)
				bb_perror_msg_and_die(bb_msg_read_error);
		} else {
			size = len;
			if (len > SRC_BUF_SIZE)
				size = SRC_BUF_SIZE;
		}
		if (!size)
			break;
		// encode the buffer we just read in
		bb_uuencode(dst_buf, src_buf, size, bb_uuenc_tbl_base64);
		if (fname) {
			printf("%s\n", eol);
		} else {
			src_buf += size;
			len -= size;
		}
		fwrite(dst_buf, 1, 4 * ((size + 2) / 3), stdout);
	}
	if (fname && NOT_LONE_DASH(fname))
		fclose(fp);
#undef src_buf
}

void FAST_FUNC decode_base64(FILE *src_stream, FILE *dst_stream)
{
	int term_count = 1;

	while (1) {
		char translated[4];
		int count = 0;

		while (count < 4) {
			char *table_ptr;
			int ch;

			/* Get next _valid_ character.
			 * global vector bb_uuenc_tbl_base64[] contains this string:
			 * "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=\n"
			 */
			do {
				ch = fgetc(src_stream);
				if (ch == EOF) {
					bb_error_msg_and_die(bb_msg_read_error);
				}
				// - means end of MIME section
				if ('-' == ch) {
					// push it back
					ungetc(ch, src_stream);
					return;
				}
				table_ptr = strchr(bb_uuenc_tbl_base64, ch);
			} while (table_ptr == NULL);

			/* Convert encoded character to decimal */
			ch = table_ptr - bb_uuenc_tbl_base64;

			if (*table_ptr == '=') {
				if (term_count == 0) {
					translated[count] = '\0';
					break;
				}
				term_count++;
			} else if (*table_ptr == '\n') {
				/* Check for terminating line */
				if (term_count == 5) {
					return;
				}
				term_count = 1;
				continue;
			} else {
				translated[count] = ch;
				count++;
				term_count = 0;
			}
		}

		/* Merge 6 bit chars to 8 bit */
		if (count > 1) {
			fputc(translated[0] << 2 | translated[1] >> 4, dst_stream);
		}
		if (count > 2) {
			fputc(translated[1] << 4 | translated[2] >> 2, dst_stream);
		}
		if (count > 3) {
			fputc(translated[2] << 6 | translated[3], dst_stream);
		}
	}
}


/*
 * get username and password from a file descriptor
 */
void FAST_FUNC get_cred_or_die(int fd)
{
	// either from TTY
	if (isatty(fd)) {
		G.user = xstrdup(bb_askpass(0, "User: "));
		G.pass = xstrdup(bb_askpass(0, "Password: "));
	// or from STDIN
	} else {
		FILE *fp = fdopen(fd, "r");
		G.user = xmalloc_fgetline(fp);
		G.pass = xmalloc_fgetline(fp);
		fclose(fp);
	}
	if (!G.user || !*G.user || !G.pass || !*G.pass)
		bb_error_msg_and_die("no username or password");
}
1	/* vi: set sw=4 ts=4: */
2	/*
3	* helper routines
4	*
5	* Copyright (C) 2008 by Vladimir Dronnikov <dronnikov@gmail.com>
6	*
7	* Licensed under GPLv2, see file LICENSE in this tarball for details.
8	*/
9	#include "libbb.h"
10	#include "mail.h"
11
12	static void kill_helper(void)
13	{
14	// TODO!!!: is there more elegant way to terminate child on program failure?
15	if (G.helper_pid > 0)
16	kill(G.helper_pid, SIGTERM);
17	}
18
19	// generic signal handler
20	static void signal_handler(int signo)
21	{
22	#define err signo
23	if (SIGALRM == signo) {
24	kill_helper();
25	bb_error_msg_and_die("timed out");
26	}
27
28	// SIGCHLD. reap zombies
29	if (safe_waitpid(G.helper_pid, &err, WNOHANG) > 0)
30	if (WIFEXITED(err)) {
31	G.helper_pid = 0;
32	if (WEXITSTATUS(err))
33	bb_error_msg_and_die("child exited (%d)", WEXITSTATUS(err));
34	}
35	#undef err
36	}
37
38	void FAST_FUNC launch_helper(const char **argv)
39	{
40	// setup vanilla unidirectional pipes interchange
41	int idx;
42	int pipes[4];
43
44	xpipe(pipes);
45	xpipe(pipes+2);
46	G.helper_pid = vfork();
47	if (G.helper_pid < 0)
48	bb_perror_msg_and_die("vfork");
49	idx = (!G.helper_pid) * 2;
50	xdup2(pipes[idx], STDIN_FILENO);
51	xdup2(pipes[3-idx], STDOUT_FILENO);
52	if (ENABLE_FEATURE_CLEAN_UP)
53	for (int i = 4; --i >= 0; )
54	if (pipes[i] > STDOUT_FILENO)
55	close(pipes[i]);
56	if (!G.helper_pid) {
57	// child: try to execute connection helper
58	BB_EXECVP(argv, (char *)argv);
59	_exit(127);
60	}
61	// parent: check whether child is alive
62	bb_signals(0
63	+ (1 << SIGCHLD)
64	+ (1 << SIGALRM)
65	, signal_handler);
66	signal_handler(SIGCHLD);
67	// child seems OK -> parent goes on
68	atexit(kill_helper);
69	}
70
71	const FAST_FUNC char command(const char fmt, const char *param)
72	{
73	const char *msg = fmt;
74	if (timeout)
75	alarm(timeout);
76	if (msg) {
77	msg = xasprintf(fmt, param);
78	printf("%s\r\n", msg);
79	}
80	fflush(stdout);
81	return msg;
82	}
83
84	// NB: parse_url can modify url[] (despite const), but only if '@' is there
85	/*
86	static char FAST_FUNC parse_url(char url, char user, char pass)
87	{
88	// parse [user[:pass]@]host
89	// return host
90	char *s = strchr(url, '@');
91	user = pass = NULL;
92	if (s) {
93	*s++ = '\0';
94	*user = url;
95	url = s;
96	s = strchr(*user, ':');
97	if (s) {
98	*s++ = '\0';
99	*pass = s;
100	}
101	}
102	return url;
103	}
104	*/
105
106	void FAST_FUNC encode_base64(char fname, const char text, const char *eol)
107	{
108	enum {
109	SRC_BUF_SIZE = 45, /* This MUST be a multiple of 3 */
110	DST_BUF_SIZE = 4 * ((SRC_BUF_SIZE + 2) / 3),
111	};
112
113	#define src_buf text
114	FILE *fp = fp;
115	ssize_t len = len;
116	char dst_buf[DST_BUF_SIZE + 1];
117
118	if (fname) {
119	fp = (NOT_LONE_DASH(fname)) ? xfopen_for_read(fname) : (FILE *)text;
120	src_buf = bb_common_bufsiz1;
121	// N.B. strlen(NULL) segfaults!
122	} else if (text) {
123	// though we do not call uuencode(NULL, NULL) explicitly
124	// still we do not want to break things suddenly
125	len = strlen(text);
126	} else
127	return;
128
129	while (1) {
130	size_t size;
131	if (fname) {
132	size = fread((char *)src_buf, 1, SRC_BUF_SIZE, fp);
133	if ((ssize_t)size < 0)
134	bb_perror_msg_and_die(bb_msg_read_error);
135	} else {
136	size = len;
137	if (len > SRC_BUF_SIZE)
138	size = SRC_BUF_SIZE;
139	}
140	if (!size)
141	break;
142	// encode the buffer we just read in
143	bb_uuencode(dst_buf, src_buf, size, bb_uuenc_tbl_base64);
144	if (fname) {
145	printf("%s\n", eol);
146	} else {
147	src_buf += size;
148	len -= size;
149	}
150	fwrite(dst_buf, 1, 4 * ((size + 2) / 3), stdout);
151	}
152	if (fname && NOT_LONE_DASH(fname))
153	fclose(fp);
154	#undef src_buf
155	}
156
157	void FAST_FUNC decode_base64(FILE src_stream, FILE dst_stream)
158	{
159	int term_count = 1;
160
161	while (1) {
162	char translated[4];
163	int count = 0;
164
165	while (count < 4) {
166	char *table_ptr;
167	int ch;
168
169	/* Get next _valid_ character.
170	* global vector bb_uuenc_tbl_base64[] contains this string:
171	* "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=\n"
172	*/
173	do {
174	ch = fgetc(src_stream);
175	if (ch == EOF) {
176	bb_error_msg_and_die(bb_msg_read_error);
177	}
178	// - means end of MIME section
179	if ('-' == ch) {
180	// push it back
181	ungetc(ch, src_stream);
182	return;
183	}
184	table_ptr = strchr(bb_uuenc_tbl_base64, ch);
185	} while (table_ptr == NULL);
186
187	/* Convert encoded character to decimal */
188	ch = table_ptr - bb_uuenc_tbl_base64;
189
190	if (*table_ptr == '=') {
191	if (term_count == 0) {
192	translated[count] = '\0';
193	break;
194	}
195	term_count++;
196	} else if (*table_ptr == '\n') {
197	/* Check for terminating line */
198	if (term_count == 5) {
199	return;
200	}
201	term_count = 1;
202	continue;
203	} else {
204	translated[count] = ch;
205	count++;
206	term_count = 0;
207	}
208	}
209
210	/* Merge 6 bit chars to 8 bit */
211	if (count > 1) {
212	fputc(translated[0] << 2 \| translated[1] >> 4, dst_stream);
213	}
214	if (count > 2) {
215	fputc(translated[1] << 4 \| translated[2] >> 2, dst_stream);
216	}
217	if (count > 3) {
218	fputc(translated[2] << 6 \| translated[3], dst_stream);
219	}
220	}
221	}
222
223
224	/*
225	* get username and password from a file descriptor
226	*/
227	void FAST_FUNC get_cred_or_die(int fd)
228	{
229	// either from TTY
230	if (isatty(fd)) {
231	G.user = xstrdup(bb_askpass(0, "User: "));
232	G.pass = xstrdup(bb_askpass(0, "Password: "));
233	// or from STDIN
234	} else {
235	FILE *fp = fdopen(fd, "r");
236	G.user = xmalloc_fgetline(fp);
237	G.pass = xmalloc_fgetline(fp);
238	fclose(fp);
239	}
240	if (!G.user \|\| !G.user \|\| !G.pass \|\| !G.pass)
241	bb_error_msg_and_die("no username or password");
242	}