sendmail: yet another maintainer's update
diff --git a/networking/sendmail.c b/networking/sendmail.c
index adc6c76..3a6078f 100644
--- a/networking/sendmail.c
+++ b/networking/sendmail.c
@@ -63,20 +63,13 @@
close(fd);
}
-static const char *const init_xargs[9] = {
- "openssl", "s_client", "-quiet", "-connect",
- NULL, "-tls1", "-starttls", "smtp"
-};
-
struct globals {
pid_t helper_pid;
unsigned timeout;
// arguments for SSL connection helper
const char *xargs[9];
-#if ENABLE_FEATURE_FETCHMAIL_FILTER
// arguments for postprocess helper
const char *fargs[3];
-#endif
};
#define G (*ptr_to_globals)
#define helper_pid (G.helper_pid)
@@ -85,16 +78,21 @@
#define fargs (G.fargs )
#define INIT_G() do { \
PTR_TO_GLOBALS = xzalloc(sizeof(G)); \
- memcpy(xargs, init_xargs, sizeof(init_xargs)); \
+ 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])
-#if ENABLE_FEATURE_FETCHMAIL_FILTER
#define opt_charset (fargs[0])
#define opt_subject (fargs[1])
-#endif
static void kill_helper(void)
{
@@ -116,11 +114,7 @@
// SIGCHLD. reap zombies
if (wait_any_nohang(&err) > 0)
if (WIFEXITED(err) && WEXITSTATUS(err))
-#if ENABLE_FEATURE_SENDMAIL_BLOATY
bb_error_msg_and_die("child exited (%d)", WEXITSTATUS(err));
-#else
- bb_error_msg_and_die("child failed");
-#endif
}
static void launch_helper(const char **argv)
@@ -141,12 +135,11 @@
if (pipes[i] > STDOUT_FILENO)
close(pipes[i]);
if (!helper_pid) {
- // child - try to execute connection helper
-// close(STDERR_FILENO);
+ // child: try to execute connection helper
BB_EXECVP(*argv, (char **)argv);
_exit(127);
}
- // parent - check whether child is alive
+ // parent: check whether child is alive
bb_signals(0
+ (1 << SIGCHLD)
+ (1 << SIGALRM)
@@ -155,13 +148,12 @@
// child seems OK -> parent goes on
}
-static char *command(const char *fmt, const char *param)
+static const char *command(const char *fmt, const char *param)
{
- char *msg = (char *)fmt;
+ const char *msg = fmt;
alarm(timeout);
if (msg) {
-// if (param)
- msg = xasprintf(fmt, param);
+ msg = xasprintf(fmt, param);
printf("%s\r\n", msg);
}
fflush(stdout);
@@ -171,25 +163,20 @@
static int smtp_checkp(const char *fmt, const char *param, int code)
{
char *answer;
- char *msg = command(fmt, param);
+ 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
-#if ENABLE_FEATURE_SENDMAIL_EHLO
while ((answer = xmalloc_getline(stdin)) != NULL)
if (strlen(answer) <= 3 || '-' != answer[3])
break;
-#else
- answer = xmalloc_getline(stdin);
-#endif
if (answer) {
int n = atoi(answer);
alarm(0);
if (ENABLE_FEATURE_CLEAN_UP) {
- free(msg);
free(answer);
}
if (-1 == code || n == code) {
@@ -200,7 +187,7 @@
bb_error_msg_and_die("%s failed", msg);
}
-static int smtp_check(const char *fmt, int code)
+static int inline smtp_check(const char *fmt, int code)
{
return smtp_checkp(fmt, NULL, code);
}
@@ -223,7 +210,7 @@
#if ENABLE_FETCHMAIL
static void pop3_checkr(const char *fmt, const char *param, char **ret)
{
- char *msg = command(fmt, param);
+ const char *msg = command(fmt, param);
char *answer = xmalloc_getline(stdin);
if (answer && '+' == *answer) {
alarm(0);
@@ -237,7 +224,7 @@
bb_error_msg_and_die("%s failed", msg);
}
-static void pop3_check(const char *fmt, const char *param)
+static void inline pop3_check(const char *fmt, const char *param)
{
pop3_checkr(fmt, param, NULL);
}
@@ -249,7 +236,7 @@
// 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"))) {
+ while ((answer = xmalloc_fgets_str(stdin, "\r\n")) != NULL) {
char *s = answer;
if ('.' == *answer) {
if ('.' == answer[1])
@@ -268,10 +255,6 @@
int sendgetmail_main(int argc, char **argv)
{
llist_t *opt_recipients = NULL;
-#if !ENABLE_FEATURE_FETCHMAIL_FILTER
- char *opt_subject;
- char *opt_charset = (char *)"utf-8";
-#endif
const char *opt_user;
const char *opt_pass;
@@ -295,8 +278,12 @@
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!)
@@ -313,7 +300,6 @@
&timeout, &opt_user, &opt_pass,
&opt_subject, &opt_charset, &opt_recipients
);
-
//argc -= optind;
argv += optind;
@@ -321,20 +307,29 @@
opt_connect = *argv++;
// connect to server
+ // SSL ordered? ->
if (opts & OPT_X) {
+ // ... use openssl helper
launch_helper(xargs);
+ // no SSL ordered? ->
} else {
- // no connection helper provided -> make plain connect
- int fd = create_and_connect_stream_or_die(opt_connect, 0);
+ // ... 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
+/***************************************************
+ * SENDMAIL
+ ***************************************************/
+
char *opt_from;
int code;
char *boundary;
@@ -342,44 +337,45 @@
const char *p;
char *q;
- // wait for initial OK on plain connect
- if (!(opts & OPT_X))
+ // we didn't use SSL helper? ->
+ if (!(opts & OPT_X)) {
+ // ... wait for initial server OK
smtp_check(NULL, 220);
+ }
- // get specified sender
+ // get the sender
opt_from = sane(*argv++);
// introduce to server
- // should we respect modern (but useless here) EHLO?
- // or should they respect we wanna be tiny?!
- if (!ENABLE_FEATURE_SENDMAIL_EHLO || 250 != smtp_checkp("EHLO %s", opt_from, -1)) {
+ // 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 ->
- // no authentication is possible
+ // 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
- // do we have username?
+ // 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 it seems we have username
- // try to authenticate
+ // 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 -> retry set sender
- // but now die on failure
+ // authenticated OK? -> retry to set sender
+ // but this time die on failure!
code = 250;
}
@@ -388,13 +384,15 @@
smtp_checkp("RCPT TO:<%s>", sane(to->data), 250);
}
- // now put message
+ // 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);
@@ -403,17 +401,17 @@
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
- // randomize
-#if ENABLE_FEATURE_SENDMAIL_BLOATY
- srand(time(NULL));
-#endif
- boundary = xasprintf("%d-%d-%d", rand(), rand(), rand());
printf(
- USE_FEATURE_SENDMAIL_BLOATY("X-Mailer: busybox " BB_VER " sendmail\r\n")
"Message-ID: <%s>\r\n"
"Mime-Version: 1.0\r\n"
"%smultipart/mixed; boundary=\"%s\"\r\n"
@@ -421,8 +419,10 @@
, "Content-Type: "
, boundary
);
- // put body + attachment(s)
+ // 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"
@@ -453,44 +453,50 @@
q = bb_get_last_path_component_strip(*argv);
}
- // put terminator
+ // put message terminator
printf("\r\n--%s--\r\n" "\r\n", boundary);
- if (ENABLE_FEATURE_CLEAN_UP)
- free(boundary);
- // end message and say goodbye
- smtp_check(".", 250);
+ // leave "put message" mode
+ smtp_check(".", 250);
+ // ... and say goodbye
smtp_check("QUIT", 221);
#if ENABLE_FETCHMAIL
} else {
- // FETCHMAIL
+/***************************************************
+ * FETCHMAIL
+ ***************************************************/
+
char *buf;
unsigned nmsg;
char *hostname;
pid_t pid;
- // cache fetch command
+
+ // 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++);
-#if ENABLE_FEATURE_FETCHMAIL_FILTER
// cache postprocess program
*fargs = *argv;
-#endif
// authenticate
if (!(opts & OPT_U)) {
//opts |= OPT_U;
- opt_user = getenv("USER");
+ // N.B. IMHO getenv("USER") can be way easily spoofed!
+ opt_user = bb_getpwuid(NULL, -1, getuid());
}
-#if ENABLE_FEATURE_FETCHMAIL_APOP
+
+ // get server greeting
pop3_checkr(NULL, NULL, &buf);
+
// server supports APOP?
if ('<' == *buf) {
md5_ctx_t md5;
- // yes. compose <stamp><password>
+ // yes! compose <stamp><password>
char *s = strchr(buf, '>');
if (s)
strcpy(s+1, opt_pass);
@@ -512,26 +518,22 @@
free(s);
free(buf-4); // buf is "+OK " away from malloc'ed string
}
+ // server ignores APOP -> use simple text authentication
} else {
-#else
- {
- pop3_check(NULL, NULL);
-#endif
// USER
pop3_check("USER %s", opt_user);
// PASS
pop3_check("PASS %s", opt_pass);
}
- // get statistics
+ // get mailbox statistics
pop3_checkr("STAT", NULL, &buf);
// prepare message filename suffix
- hostname = xzalloc(MAXHOSTNAMELEN+1);
- gethostname(hostname, MAXHOSTNAMELEN);
+ hostname = safe_gethostname();
pid = getpid();
- // get number of messages
+ // 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
@@ -542,19 +544,19 @@
// loop through messages
for (; nmsg; nmsg--) {
+
+ // generate unique filename
char *filename = xasprintf("tmp/%llu.%u.%s", monotonic_us(), pid, hostname);
char *target;
-#if ENABLE_FEATURE_FETCHMAIL_FILTER
- int rc;
-#endif
- // retrieve message in ./tmp
+ int rc;
+
+ // retrieve message in ./tmp/
pop3_check(retr, (const char *)nmsg);
pop3_message(filename);
// delete message from server
if (opts & OPTF_z)
pop3_check("DELE %u", (const char*)nmsg);
-#if ENABLE_FEATURE_FETCHMAIL_FILTER
// run postprocessing program
if (*fargs) {
fargs[1] = filename;
@@ -564,23 +566,18 @@
if (1 == rc)
goto skip;
}
-#endif
- // atomically move message to ./new
+
+ // 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);
-#if ENABLE_FEATURE_FETCHMAIL_FILTER
skip:
-#endif
free(filename);
}
- if (ENABLE_FEATURE_CLEAN_UP)
- free(hostname);
-
// Bye
pop3_check("QUIT", NULL);
#endif // ENABLE_FETCHMAIL