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)
{
	if (G.helper_pid > 0) {
		kill(G.helper_pid, SIGTERM);
		G.helper_pid = 0;
	}
}

// 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 (WIFSIGNALED(err))
			bb_error_msg_and_die("helper killed by signal %u", WTERMSIG(err));
		if (WIFEXITED(err)) {
			G.helper_pid = 0;
			if (WEXITSTATUS(err))
				bb_error_msg_and_die("helper exited (%u)", WEXITSTATUS(err));
		}
	}
#undef err
}

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

	xpipe(pipes);
	xpipe(pipes + 2);

	// NB: handler must be installed before vfork
	bb_signals(0
		+ (1 << SIGCHLD)
		+ (1 << SIGALRM)
		, signal_handler);

	G.helper_pid = vfork();
	if (G.helper_pid < 0)
		bb_perror_msg_and_die("vfork");

	i = (!G.helper_pid) * 2; // for parent:0, for child:2
	close(pipes[i + 1]); // 1 or 3 - closing one write end
	close(pipes[2 - i]); // 2 or 0 - closing one read end
	xmove_fd(pipes[i], STDIN_FILENO); // 0 or 2 - using other read end
	xmove_fd(pipes[3 - i], STDOUT_FILENO); // 3 or 1 - other write end

	if (!G.helper_pid) {
		// child: try to execute connection helper
		// NB: SIGCHLD & SIGALRM revert to SIG_DFL on exec
		BB_EXECVP(*argv, (char **)argv);
		_exit(127);
	}

	// parent
	// check whether child is alive
	//redundant: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_all();
	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)
{
	if (isatty(fd)) {
		G.user = xstrdup(bb_ask(fd, /* timeout: */ 0, "User: "));
		G.pass = xstrdup(bb_ask(fd, /* timeout: */ 0, "Password: "));
	} else {
		G.user = xmalloc_reads(fd, /* pfx: */ NULL, /* maxsize: */ NULL);
		G.pass = xmalloc_reads(fd, /* pfx: */ NULL, /* maxsize: */ NULL);
	}
	if (!G.user || !*G.user || !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	if (G.helper_pid > 0) {
15	kill(G.helper_pid, SIGTERM);
16	G.helper_pid = 0;
17	}
18	}
19
20	// generic signal handler
21	static void signal_handler(int signo)
22	{
23	#define err signo
24	if (SIGALRM == signo) {
25	kill_helper();
26	bb_error_msg_and_die("timed out");
27	}
28
29	// SIGCHLD. reap zombies
30	if (safe_waitpid(G.helper_pid, &err, WNOHANG) > 0) {
31	if (WIFSIGNALED(err))
32	bb_error_msg_and_die("helper killed by signal %u", WTERMSIG(err));
33	if (WIFEXITED(err)) {
34	G.helper_pid = 0;
35	if (WEXITSTATUS(err))
36	bb_error_msg_and_die("helper exited (%u)", WEXITSTATUS(err));
37	}
38	}
39	#undef err
40	}
41
42	void FAST_FUNC launch_helper(const char **argv)
43	{
44	// setup vanilla unidirectional pipes interchange
45	int i;
46	int pipes[4];
47
48	xpipe(pipes);
49	xpipe(pipes + 2);
50
51	// NB: handler must be installed before vfork
52	bb_signals(0
53	+ (1 << SIGCHLD)
54	+ (1 << SIGALRM)
55	, signal_handler);
56
57	G.helper_pid = vfork();
58	if (G.helper_pid < 0)
59	bb_perror_msg_and_die("vfork");
60
61	i = (!G.helper_pid) * 2; // for parent:0, for child:2
62	close(pipes[i + 1]); // 1 or 3 - closing one write end
63	close(pipes[2 - i]); // 2 or 0 - closing one read end
64	xmove_fd(pipes[i], STDIN_FILENO); // 0 or 2 - using other read end
65	xmove_fd(pipes[3 - i], STDOUT_FILENO); // 3 or 1 - other write end
66
67	if (!G.helper_pid) {
68	// child: try to execute connection helper
69	// NB: SIGCHLD & SIGALRM revert to SIG_DFL on exec
70	BB_EXECVP(argv, (char *)argv);
71	_exit(127);
72	}
73
74	// parent
75	// check whether child is alive
76	//redundant:signal_handler(SIGCHLD);
77	// child seems OK -> parent goes on
78	atexit(kill_helper);
79	}
80
81	const FAST_FUNC char command(const char fmt, const char *param)
82	{
83	const char *msg = fmt;
84	if (timeout)
85	alarm(timeout);
86	if (msg) {
87	msg = xasprintf(fmt, param);
88	printf("%s\r\n", msg);
89	}
90	fflush_all();
91	return msg;
92	}
93
94	// NB: parse_url can modify url[] (despite const), but only if '@' is there
95	/*
96	static char FAST_FUNC parse_url(char url, char user, char pass)
97	{
98	// parse [user[:pass]@]host
99	// return host
100	char *s = strchr(url, '@');
101	user = pass = NULL;
102	if (s) {
103	*s++ = '\0';
104	*user = url;
105	url = s;
106	s = strchr(*user, ':');
107	if (s) {
108	*s++ = '\0';
109	*pass = s;
110	}
111	}
112	return url;
113	}
114	*/
115
116	void FAST_FUNC encode_base64(char fname, const char text, const char *eol)
117	{
118	enum {
119	SRC_BUF_SIZE = 45, /* This MUST be a multiple of 3 */
120	DST_BUF_SIZE = 4 * ((SRC_BUF_SIZE + 2) / 3),
121	};
122
123	#define src_buf text
124	FILE *fp = fp;
125	ssize_t len = len;
126	char dst_buf[DST_BUF_SIZE + 1];
127
128	if (fname) {
129	fp = (NOT_LONE_DASH(fname)) ? xfopen_for_read(fname) : (FILE *)text;
130	src_buf = bb_common_bufsiz1;
131	// N.B. strlen(NULL) segfaults!
132	} else if (text) {
133	// though we do not call uuencode(NULL, NULL) explicitly
134	// still we do not want to break things suddenly
135	len = strlen(text);
136	} else
137	return;
138
139	while (1) {
140	size_t size;
141	if (fname) {
142	size = fread((char *)src_buf, 1, SRC_BUF_SIZE, fp);
143	if ((ssize_t)size < 0)
144	bb_perror_msg_and_die(bb_msg_read_error);
145	} else {
146	size = len;
147	if (len > SRC_BUF_SIZE)
148	size = SRC_BUF_SIZE;
149	}
150	if (!size)
151	break;
152	// encode the buffer we just read in
153	bb_uuencode(dst_buf, src_buf, size, bb_uuenc_tbl_base64);
154	if (fname) {
155	printf("%s\n", eol);
156	} else {
157	src_buf += size;
158	len -= size;
159	}
160	fwrite(dst_buf, 1, 4 * ((size + 2) / 3), stdout);
161	}
162	if (fname && NOT_LONE_DASH(fname))
163	fclose(fp);
164	#undef src_buf
165	}
166
167	void FAST_FUNC decode_base64(FILE src_stream, FILE dst_stream)
168	{
169	int term_count = 1;
170
171	while (1) {
172	char translated[4];
173	int count = 0;
174
175	while (count < 4) {
176	char *table_ptr;
177	int ch;
178
179	/* Get next _valid_ character.
180	* global vector bb_uuenc_tbl_base64[] contains this string:
181	* "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=\n"
182	*/
183	do {
184	ch = fgetc(src_stream);
185	if (ch == EOF) {
186	bb_error_msg_and_die(bb_msg_read_error);
187	}
188	// - means end of MIME section
189	if ('-' == ch) {
190	// push it back
191	ungetc(ch, src_stream);
192	return;
193	}
194	table_ptr = strchr(bb_uuenc_tbl_base64, ch);
195	} while (table_ptr == NULL);
196
197	/* Convert encoded character to decimal */
198	ch = table_ptr - bb_uuenc_tbl_base64;
199
200	if (*table_ptr == '=') {
201	if (term_count == 0) {
202	translated[count] = '\0';
203	break;
204	}
205	term_count++;
206	} else if (*table_ptr == '\n') {
207	/* Check for terminating line */
208	if (term_count == 5) {
209	return;
210	}
211	term_count = 1;
212	continue;
213	} else {
214	translated[count] = ch;
215	count++;
216	term_count = 0;
217	}
218	}
219
220	/* Merge 6 bit chars to 8 bit */
221	if (count > 1) {
222	fputc(translated[0] << 2 \| translated[1] >> 4, dst_stream);
223	}
224	if (count > 2) {
225	fputc(translated[1] << 4 \| translated[2] >> 2, dst_stream);
226	}
227	if (count > 3) {
228	fputc(translated[2] << 6 \| translated[3], dst_stream);
229	}
230	}
231	}
232
233
234	/*
235	* get username and password from a file descriptor
236	*/
237	void FAST_FUNC get_cred_or_die(int fd)
238	{
239	if (isatty(fd)) {
240	G.user = xstrdup(bb_ask(fd, /* timeout: */ 0, "User: "));
241	G.pass = xstrdup(bb_ask(fd, /* timeout: */ 0, "Password: "));
242	} else {
243	G.user = xmalloc_reads(fd, /* pfx: / NULL, / maxsize: */ NULL);
244	G.pass = xmalloc_reads(fd, /* pfx: / NULL, / maxsize: */ NULL);
245	}
246	if (!G.user \|\| !*G.user \|\| !G.pass)
247	bb_error_msg_and_die("no username or password");
248	}