sendmail: make -f optional, document its default value

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko 2014-02-05 15:01:39 +01:00
parent e4785ca653
commit 07f417b6ab

View File

@ -15,7 +15,8 @@
//usage: "Read email from stdin and send it\n"
//usage: "\nStandard options:"
//usage: "\n -t Read additional recipients from message body"
//usage: "\n -f SENDER Sender (required)"
//usage: "\n -f SENDER For use in MAIL FROM:<sender>. Can be empty string"
//usage: "\n Default: -auUSER, or username of current UID"
//usage: "\n -o OPTIONS Various options. -oi implied, others are ignored"
//usage: "\n -i -oi synonym. implied and ignored"
//usage: "\n"
@ -40,6 +41,52 @@
//usage: "\nUse makemime to create emails with attachments"
//usage: )
/* Currently we don't sanitize or escape user-supplied SENDER and RECIPIENT_EMAILs.
* We may need to do so. For one, '.' in usernames seems to require escaping!
*
* From http://cr.yp.to/smtp/address.html:
*
* SMTP offers three ways to encode a character inside an address:
*
* "safe": the character, if it is not <>()[].,;:@, backslash,
* double-quote, space, or an ASCII control character;
* "quoted": the character, if it is not \012, \015, backslash,
* or double-quote; or
* "slashed": backslash followed by the character.
*
* An encoded box part is either (1) a sequence of one or more slashed
* or safe characters or (2) a double quote, a sequence of zero or more
* slashed or quoted characters, and a double quote. It represents
* the concatenation of the characters encoded inside it.
*
* For example, the encoded box parts
* angels
* \a\n\g\e\l\s
* "\a\n\g\e\l\s"
* "angels"
* "ang\els"
* all represent the 6-byte string "angels", and the encoded box parts
* a\,comma
* \a\,\c\o\m\m\a
* "a,comma"
* all represent the 7-byte string "a,comma".
*
* An encoded address contains
* the byte <;
* optionally, a route followed by a colon;
* an encoded box part, the byte @, and a domain; and
* the byte >.
*
* It represents an Internet mail address, given by concatenating
* the string represented by the encoded box part, the byte @,
* and the domain. For example, the encoded addresses
* <God@heaven.af.mil>
* <\God@heaven.af.mil>
* <"God"@heaven.af.mil>
* <@gateway.af.mil,@uucp.local:"\G\o\d"@heaven.af.mil>
* all represent the Internet mail address "God@heaven.af.mil".
*/
#include "libbb.h"
#include "mail.h"
@ -163,7 +210,7 @@ int sendmail_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int sendmail_main(int argc UNUSED_PARAM, char **argv)
{
char *opt_connect = opt_connect;
char *opt_from;
char *opt_from = NULL;
char *s;
llist_t *list = NULL;
char *host = sane_address(safe_gethostname());
@ -199,8 +246,8 @@ int sendmail_main(int argc UNUSED_PARAM, char **argv)
G.fp0 = xfdopen_for_read(3);
// parse options
// -v is a counter, -f is required. -H and -S are mutually exclusive, -a is a list
opt_complementary = "vv:f:w+:H--S:S--H:a::";
// -v is a counter, -H and -S are mutually exclusive, -a is a list
opt_complementary = "vv:w+:H--S:S--H:a::";
// N.B. since -H and -S are mutually exclusive they do not interfere in opt_connect
// -a is for ssmtp (http://downloads.openwrt.org/people/nico/man/man8/ssmtp.8.html) compatibility,
// it is still under development.
@ -304,13 +351,11 @@ int sendmail_main(int argc UNUSED_PARAM, char **argv)
// Since reading from console may defeat usability, the solution is either to read from a predefined
// file descriptor (e.g. 4), or again from a secured file.
// got no sender address? -> use system username as a resort
// N.B. we marked -f as required option!
//if (!G.user) {
// // N.B. IMHO getenv("USER") can be way easily spoofed!
// G.user = xuid2uname(getuid());
// opt_from = xasprintf("%s@%s", G.user, domain);
//}
// got no sender address? use auth name, then UID username as a last resort
if (!opt_from) {
opt_from = G.user ? G.user : xuid2uname(getuid());
}
smtp_checkp("MAIL FROM:<%s>", opt_from, 250);
// process message