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authorDenys Vlasenko <vda.linux@googlemail.com>2014-02-05 14:01:39 (GMT)
committer Denys Vlasenko <vda.linux@googlemail.com>2014-02-05 14:01:39 (GMT)
commit07f417b6ab92e0429f302ff6783bb9681b60120e (patch)
tree4d1faf78aad2c22abf6fb536f44bd24b808f6865
parente4785ca653d0e219926692c229673b2c1b8d6ac4 (diff)
downloadbusybox-07f417b6ab92e0429f302ff6783bb9681b60120e.tar.gz
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sendmail: make -f optional, document its default value
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
-rw-r--r--mailutils/sendmail.c67
1 files changed, 56 insertions, 11 deletions
diff --git a/mailutils/sendmail.c b/mailutils/sendmail.c
index b5aa1d1..824109d 100644
--- a/mailutils/sendmail.c
+++ b/mailutils/sendmail.c
@@ -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