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path: root/polux/application/busybox/networking/sendmail.c
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Diffstat (limited to 'polux/application/busybox/networking/sendmail.c')
-rw-r--r--polux/application/busybox/networking/sendmail.c587
1 files changed, 587 insertions, 0 deletions
diff --git a/polux/application/busybox/networking/sendmail.c b/polux/application/busybox/networking/sendmail.c
new file mode 100644
index 0000000000..2eb01dc94e
--- /dev/null
+++ b/polux/application/busybox/networking/sendmail.c
@@ -0,0 +1,587 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * bare bones sendmail/fetchmail
+ *
+ * Copyright (C) 2008 by Vladimir Dronnikov <dronnikov@gmail.com>
+ *
+ * Licensed under GPLv2, see file LICENSE in this tarball for details.
+ */
+#include "libbb.h"
+
+#define INITIAL_STDIN_FILENO 3
+
+static void uuencode(char *fname, const char *text)
+{
+ 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
+ int fd;
+#define len fd
+ char dst_buf[DST_BUF_SIZE + 1];
+
+ if (fname) {
+ fd = INITIAL_STDIN_FILENO;
+ if (NOT_LONE_DASH(fname))
+ fd = xopen(fname, O_RDONLY);
+ 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;
+
+ fflush(stdout); // sync stdio and unistd output
+ while (1) {
+ size_t size;
+ if (fname) {
+ size = full_read(fd, (char *)src_buf, SRC_BUF_SIZE);
+ 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) {
+ xwrite(STDOUT_FILENO, "\r\n", 2);
+ } else {
+ src_buf += size;
+ len -= size;
+ }
+ xwrite(STDOUT_FILENO, dst_buf, 4 * ((size + 2) / 3));
+ }
+ if (fname)
+ close(fd);
+}
+
+struct globals {
+ pid_t helper_pid;
+ unsigned timeout;
+ // arguments for SSL connection helper
+ const char *xargs[9];
+ // arguments for postprocess helper
+ const char *fargs[3];
+};
+#define G (*ptr_to_globals)
+#define helper_pid (G.helper_pid)
+#define timeout (G.timeout )
+#define xargs (G.xargs )
+#define fargs (G.fargs )
+#define INIT_G() do { \
+ SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
+ xargs[0] = "openssl"; \
+ xargs[1] = "s_client"; \
+ xargs[2] = "-quiet"; \
+ xargs[3] = "-connect"; \
+ /*xargs[4] = "server[:port]";*/ \
+ xargs[5] = "-tls1"; \
+ xargs[6] = "-starttls"; \
+ xargs[7] = "smtp"; \
+ fargs[0] = "utf-8"; \
+} while (0)
+
+#define opt_connect (xargs[4])
+#define opt_after_connect (xargs[5])
+#define opt_charset (fargs[0])
+#define opt_subject (fargs[1])
+
+static void kill_helper(void)
+{
+ // TODO!!!: is there more elegant way to terminate child on program failure?
+ if (helper_pid > 0)
+ kill(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 (wait_any_nohang(&err) > 0)
+ if (WIFEXITED(err) && WEXITSTATUS(err))
+ bb_error_msg_and_die("child exited (%d)", WEXITSTATUS(err));
+}
+
+static void launch_helper(const char **argv)
+{
+ // setup vanilla unidirectional pipes interchange
+ int idx;
+ int pipes[4];
+ xpipe(pipes);
+ xpipe(pipes+2);
+ helper_pid = vfork();
+ if (helper_pid < 0)
+ bb_perror_msg_and_die("vfork");
+ idx = (!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 (!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
+}
+
+static const char *command(const char *fmt, const char *param)
+{
+ const char *msg = fmt;
+ alarm(timeout);
+ if (msg) {
+ msg = xasprintf(fmt, param);
+ printf("%s\r\n", msg);
+ }
+ fflush(stdout);
+ return msg;
+}
+
+static int smtp_checkp(const char *fmt, const char *param, int code)
+{
+ char *answer;
+ const char *msg = command(fmt, param);
+ // read stdin
+ // if the string has a form \d\d\d- -- read next string. E.g. EHLO response
+ // parse first bytes to a number
+ // if code = -1 then just return this number
+ // if code != -1 then checks whether the number equals the code
+ // if not equal -> die saying msg
+ while ((answer = xmalloc_getline(stdin)) != NULL)
+ if (strlen(answer) <= 3 || '-' != answer[3])
+ break;
+ if (answer) {
+ int n = atoi(answer);
+ alarm(0);
+ if (ENABLE_FEATURE_CLEAN_UP) {
+ free(answer);
+ }
+ if (-1 == code || n == code) {
+ return n;
+ }
+ }
+ kill_helper();
+ bb_error_msg_and_die("%s failed", msg);
+}
+
+static int inline smtp_check(const char *fmt, int code)
+{
+ return smtp_checkp(fmt, NULL, code);
+}
+
+// strip argument of bad chars
+static char *sane(char *str)
+{
+ char *s = str;
+ char *p = s;
+ while (*s) {
+ if (isalnum(*s) || '_' == *s || '-' == *s || '.' == *s || '@' == *s) {
+ *p++ = *s;
+ }
+ s++;
+ }
+ *p = '\0';
+ return str;
+}
+
+#if ENABLE_FETCHMAIL
+static void pop3_checkr(const char *fmt, const char *param, char **ret)
+{
+ const char *msg = command(fmt, param);
+ char *answer = xmalloc_getline(stdin);
+ if (answer && '+' == *answer) {
+ alarm(0);
+ if (ret)
+ *ret = answer+4; // skip "+OK "
+ else if (ENABLE_FEATURE_CLEAN_UP)
+ free(answer);
+ return;
+ }
+ kill_helper();
+ bb_error_msg_and_die("%s failed", msg);
+}
+
+static void inline pop3_check(const char *fmt, const char *param)
+{
+ pop3_checkr(fmt, param, NULL);
+}
+
+static void pop3_message(const char *filename)
+{
+ int fd;
+ char *answer;
+ // create and open file filename
+ // read stdin, copy to created file
+ fd = xopen(filename, O_CREAT | O_WRONLY | O_TRUNC | O_EXCL);
+ while ((answer = xmalloc_fgets_str(stdin, "\r\n")) != NULL) {
+ char *s = answer;
+ if ('.' == *answer) {
+ if ('.' == answer[1])
+ s++;
+ else if ('\r' == answer[1] && '\n' == answer[2] && '\0' == answer[3])
+ break;
+ }
+ xwrite(fd, s, strlen(s));
+ free(answer);
+ }
+ close(fd);
+}
+#endif
+
+int sendgetmail_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int sendgetmail_main(int argc ATTRIBUTE_UNUSED, char **argv)
+{
+ llist_t *opt_recipients = NULL;
+
+ const char *opt_user;
+ const char *opt_pass;
+
+ enum {
+ OPT_w = 1 << 0, // network timeout
+ OPT_U = 1 << 1, // user
+ OPT_P = 1 << 2, // password
+ OPT_X = 1 << 3, // connect using openssl s_client helper
+
+ OPTS_n = 1 << 4, // sendmail: request notification
+ OPTF_t = 1 << 4, // fetchmail: use "TOP" not "RETR"
+
+ OPTS_s = 1 << 5, // sendmail: subject
+ OPTF_z = 1 << 5, // fetchmail: delete from server
+
+ OPTS_c = 1 << 6, // sendmail: assumed charset
+ OPTS_t = 1 << 7, // sendmail: recipient(s)
+ };
+
+ const char *options;
+ unsigned opts;
+
+ // init global variables
+ INIT_G();
+
+ // parse options, different option sets for sendmail and fetchmail
+ // N.B. opt_after_connect hereafter is NULL if we are called as fetchmail
+ // and is NOT NULL if we are called as sendmail
+ if (!ENABLE_FETCHMAIL || 's' == applet_name[0]) {
+ // SENDMAIL
+ // save initial stdin (body or attachements can be piped!)
+ xdup2(STDIN_FILENO, INITIAL_STDIN_FILENO);
+ opt_complementary = "-2:w+:t:t::"; // count(-t) > 0
+ options = "w:U:P:X" "ns:c:t:";
+ } else {
+ // FETCHMAIL
+ opt_after_connect = NULL;
+ opt_complementary = "-2:w+:P";
+ options = "w:U:P:X" "tz";
+ }
+ opts = getopt32(argv, options,
+ &timeout, &opt_user, &opt_pass,
+ &opt_subject, &opt_charset, &opt_recipients
+ );
+ //argc -= optind;
+ argv += optind;
+
+ // first argument is remote server[:port]
+ opt_connect = *argv++;
+
+ // connect to server
+ // SSL ordered? ->
+ if (opts & OPT_X) {
+ // ... use openssl helper
+ launch_helper(xargs);
+ // no SSL ordered? ->
+ } else {
+ // ... make plain connect
+ int fd = create_and_connect_stream_or_die(opt_connect, 25);
+ // make ourselves a simple IO filter
+ // from now we know nothing about network :)
+ xmove_fd(fd, STDIN_FILENO);
+ xdup2(STDIN_FILENO, STDOUT_FILENO);
+ }
+
+#if ENABLE_FETCHMAIL
+ // we are sendmail?
+ if (opt_after_connect)
+#endif
+ {
+/***************************************************
+ * SENDMAIL
+ ***************************************************/
+
+ char *opt_from;
+ int code;
+ char *boundary;
+ const char *fmt;
+ const char *p;
+ char *q;
+
+ // we didn't use SSL helper? ->
+ if (!(opts & OPT_X)) {
+ // ... wait for initial server OK
+ smtp_check(NULL, 220);
+ }
+
+ // get the sender
+ opt_from = sane(*argv++);
+
+ // introduce to server
+ // we should start with modern EHLO
+ if (250 != smtp_checkp("EHLO %s", opt_from, -1)) {
+ smtp_checkp("HELO %s", opt_from, 250);
+ }
+
+ // set sender
+ // NOTE: if password has not been specified
+ // then no authentication is possible
+ code = (opts & OPT_P) ? -1 : 250;
+ // first try softly without authentication
+ while (250 != smtp_checkp("MAIL FROM:<%s>", opt_from, code)) {
+ // MAIL FROM failed -> authentication needed
+ // have we got username?
+ if (!(opts & OPT_U)) {
+ // no! fetch it from "from" option
+ //opts |= OPT_U;
+ opt_user = xstrdup(opt_from);
+ *strchrnul(opt_user, '@') = '\0';
+ }
+ // now we've got username
+ // so try to authenticate
+ if (334 == smtp_check("AUTH LOGIN", -1)) {
+ uuencode(NULL, opt_user);
+ smtp_check("", 334);
+ uuencode(NULL, opt_pass);
+ smtp_check("", 235);
+ }
+ // authenticated OK? -> retry to set sender
+ // but this time die on failure!
+ code = 250;
+ }
+
+ // set recipients
+ for (llist_t *to = opt_recipients; to; to = to->link) {
+ smtp_checkp("RCPT TO:<%s>", sane(to->data), 250);
+ }
+
+ // enter "put message" mode
+ smtp_check("DATA", 354);
+
+ // put address headers
+ printf("From: %s\r\n", opt_from);
+ for (llist_t *to = opt_recipients; to; to = to->link) {
+ printf("To: %s\r\n", to->data);
+ }
+
+ // put encoded subject
+ if (opts & OPTS_c)
+ sane((char *)opt_charset);
+ if (opts & OPTS_s) {
+ printf("Subject: =?%s?B?", opt_charset);
+ uuencode(NULL, opt_subject);
+ printf("?=\r\n");
+ }
+
+ // put notification
+ if (opts & OPTS_n)
+ printf("Disposition-Notification-To: %s\r\n", opt_from);
+
+ // make a random string -- it will delimit message parts
+ srand(monotonic_us());
+ boundary = xasprintf("%d-%d-%d", rand(), rand(), rand());
+
+ // put common headers and body start
+ printf(
+ "Message-ID: <%s>\r\n"
+ "Mime-Version: 1.0\r\n"
+ "%smultipart/mixed; boundary=\"%s\"\r\n"
+ , boundary
+ , "Content-Type: "
+ , boundary
+ );
+
+ // put body + attachment(s)
+ // N.B. all these weird things just to be tiny
+ // by reusing string patterns!
+ fmt =
+ "\r\n--%s\r\n"
+ "%stext/plain; charset=%s\r\n"
+ "%s%s\r\n"
+ "%s"
+ ;
+ p = opt_charset;
+ q = (char *)"";
+ while (*argv) {
+ printf(
+ fmt
+ , boundary
+ , "Content-Type: "
+ , p
+ , "Content-Disposition: inline"
+ , q
+ , "Content-Transfer-Encoding: base64\r\n"
+ );
+ p = "";
+ fmt =
+ "\r\n--%s\r\n"
+ "%sapplication/octet-stream%s\r\n"
+ "%s; filename=\"%s\"\r\n"
+ "%s"
+ ;
+ uuencode(*argv, NULL);
+ if (*(++argv))
+ q = bb_get_last_path_component_strip(*argv);
+ }
+
+ // put message terminator
+ printf("\r\n--%s--\r\n" "\r\n", boundary);
+
+ // leave "put message" mode
+ smtp_check(".", 250);
+ // ... and say goodbye
+ smtp_check("QUIT", 221);
+
+#if ENABLE_FETCHMAIL
+ } else {
+/***************************************************
+ * FETCHMAIL
+ ***************************************************/
+
+ char *buf;
+ unsigned nmsg;
+ char *hostname;
+ pid_t pid;
+
+ // cache fetch command:
+ // TOP will return only the headers
+ // RETR will dump the whole message
+ const char *retr = (opts & OPTF_t) ? "TOP %u 0" : "RETR %u";
+
+ // goto maildir
+ xchdir(*argv++);
+
+ // cache postprocess program
+ *fargs = *argv;
+
+ // authenticate
+ if (!(opts & OPT_U)) {
+ //opts |= OPT_U;
+ // N.B. IMHO getenv("USER") can be way easily spoofed!
+ opt_user = bb_getpwuid(NULL, -1, getuid());
+ }
+
+ // get server greeting
+ pop3_checkr(NULL, NULL, &buf);
+
+ // server supports APOP?
+ if ('<' == *buf) {
+ md5_ctx_t md5;
+ // yes! compose <stamp><password>
+ char *s = strchr(buf, '>');
+ if (s)
+ strcpy(s+1, opt_pass);
+ s = buf;
+ // get md5 sum of <stamp><password>
+ md5_begin(&md5);
+ md5_hash(s, strlen(s), &md5);
+ md5_end(s, &md5);
+ // NOTE: md5 struct contains enough space
+ // so we reuse md5 space instead of xzalloc(16*2+1)
+#define md5_hex ((uint8_t *)&md5)
+// uint8_t *md5_hex = (uint8_t *)&md5;
+ *bin2hex(md5_hex, s, 16) = '\0';
+ // APOP
+ s = xasprintf("%s %s", opt_user, md5_hex);
+#undef md5_hex
+ pop3_check("APOP %s", s);
+ if (ENABLE_FEATURE_CLEAN_UP) {
+ free(s);
+ free(buf-4); // buf is "+OK " away from malloc'ed string
+ }
+ // server ignores APOP -> use simple text authentication
+ } else {
+ // USER
+ pop3_check("USER %s", opt_user);
+ // PASS
+ pop3_check("PASS %s", opt_pass);
+ }
+
+ // get mailbox statistics
+ pop3_checkr("STAT", NULL, &buf);
+
+ // prepare message filename suffix
+ hostname = safe_gethostname();
+ pid = getpid();
+
+ // get messages counter
+ // NOTE: we don't use xatou(buf) since buf is "nmsg nbytes"
+ // we only need nmsg and atoi is just exactly what we need
+ // if atoi fails to convert buf into number it returns 0
+ // in this case the following loop simply will not be executed
+ nmsg = atoi(buf);
+ if (ENABLE_FEATURE_CLEAN_UP)
+ free(buf-4); // buf is "+OK " away from malloc'ed string
+
+ // loop through messages
+ for (; nmsg; nmsg--) {
+
+ // generate unique filename
+ char *filename = xasprintf("tmp/%llu.%u.%s", monotonic_us(), pid, hostname);
+ char *target;
+ int rc;
+
+ // retrieve message in ./tmp/
+ pop3_check(retr, (const char *)(ptrdiff_t)nmsg);
+ pop3_message(filename);
+ // delete message from server
+ if (opts & OPTF_z)
+ pop3_check("DELE %u", (const char*)(ptrdiff_t)nmsg);
+
+ // run postprocessing program
+ if (*fargs) {
+ fargs[1] = filename;
+ rc = wait4pid(spawn((char **)fargs));
+ if (99 == rc)
+ break;
+ if (1 == rc)
+ goto skip;
+ }
+
+ // atomically move message to ./new/
+ target = xstrdup(filename);
+ strncpy(target, "new", 3);
+ // ... or just stop receiving on error
+ if (rename_or_warn(filename, target))
+ break;
+ free(target);
+ skip:
+ free(filename);
+ }
+
+ // Bye
+ pop3_check("QUIT", NULL);
+#endif // ENABLE_FETCHMAIL
+ }
+
+ return 0;
+}