Reproducible builds

At the moment ngircd fails the tests for reproducible builds in Debian
since it uses the __DATE__ and __TIME__ macros for the INFO command.

Instead of patching this out I decided to implement an optional
constant BIRTHTIME that allows you to set a time stamp for the "Birth
Date" information, in seconds since the epoch, like in

    export CFLAGS += -DBIRTHTIME=$(shell date +%s --date="2015/08/15 23:42:22")

In the future, Debian will provide a SOURCE_DATE_EPOCH environment
variable, dealing with the situation until then will be my job.

The time format was taken from the NGIRCd_StartStr formatting in
ngircd.c so the "Birth Date" and "On-line since" lines in the INFO
output look similar:

    :irc.example.net 371 nick :ngIRCd 22.1-IDENT+IPv6+IRCPLUS+PAM+SSL+SYSLOG+ZLIB-x86_64/pc/linux-gnu
    :irc.example.net 371 nick :Birth Date: Tue Aug 25 2015 at 18:11:11 (CEST)
    :irc.example.net 371 nick :On-line since Tue Aug 25 2015 at 18:11:33 (CEST)
    :irc.example.net 374 nick :End of INFO list

The format of the time stamped is changed, but as far as I can tell, there's no
rule that is violated by that.

Bonus level: Reformat the messages so the time stamps are aligned.

diff --git a/src/ngircd/irc-info.c b/src/ngircd/irc-info.c
index 1bbaf57b3b53a35e905be647c5f075690ade38ac..1788bf60feebf6e1733b0e92c4070d1f0848250f 100644 (file)
--- a/src/ngircd/irc-info.c
+++ b/src/ngircd/irc-info.c
@@ -558,7 +558,15 @@ IRC_INFO(CLIENT * Client, REQUEST * Req)
                                NGIRCd_Version))
                return DISCONNECTED;
 
-#if defined(__DATE__) && defined(__TIME__)
+#if defined(BIRTHDATE)
+       char t_str[60];
+       time_t t = BIRTHDATE;
+       (void)strftime(t_str, sizeof(t_str), "%a %b %d %Y at %H:%M:%S (%Z)",
+                       localtime(&t));
+       snprintf(msg, sizeof(msg), "Birth Date: %s", t_str);
+       if (!IRC_WriteStrClient(Client, RPL_INFO_MSG, Client_ID(prefix), msg))
+               return DISCONNECTED;
+#elif defined(__DATE__) && defined(__TIME__)
        snprintf(msg, sizeof(msg), "Birth Date: %s at %s", __DATE__, __TIME__);
        if (!IRC_WriteStrClient(Client, RPL_INFO_MSG, Client_ID(prefix), msg))
                return DISCONNECTED;