Re: [PATCH] daemon: restore getpeername(0,...) use

> This reverts f9c87be6b42dd0f8b31a4bb8c6a44326879fdd1a, in a sense,
> because that commit broke logging of "Connection from ..." when
> git-daemon is run under xinetd.
>
> This patch here computes the text representation of the peer and then
> copies that to environment variables such that the code in execute()
> and subfunctions can stay as-is.
>
> Signed-off-by: Jan Engelhardt <jengelh@inai.de>
> ---
>  daemon.c |   55 +++++++++++++++++++++++++++++++++++++++++++++++++++----
>  1 file changed, 51 insertions(+), 4 deletions(-)
>
> diff --git a/daemon.c b/daemon.c
> index 4602b46..eaf08c2 100644
> --- a/daemon.c
> +++ b/daemon.c
> @@ -1,3 +1,4 @@
> +#include <stdbool.h>
>  #include "cache.h"
>  #include "pkt-line.h"
>  #include "exec_cmd.h"

> @@ -1164,6 +1165,54 @@ static int serve(struct string_list *listen_addr, int listen_port,
>  	return service_loop(&socklist);
>  }
>  
> +static void inetd_mode_prepare(void)
> +{
> +	struct sockaddr_storage ss;
> +	struct sockaddr *addr = (void *)&ss;
> +	socklen_t slen = sizeof(ss);
> +	char addrbuf[256], portbuf[6] = "";
> +
> +	if (!freopen("/dev/null", "w", stderr))
> +		die_errno("failed to redirect stderr to /dev/null");
> +
> +	/*
> +	 * Windows is said to not be able to handle this, so we will simply
> +	 * ignore failure here. (It only affects a log message anyway.)
> +	 */
> +	if (getpeername(0, addr, &slen) < 0)
> +		return;
> +
> +	if (addr->sa_family == AF_INET) {
> +		const struct sockaddr_in *sin_addr = (void *)addr;
> +
> +		if (inet_ntop(addr->sa_family, &sin_addr->sin_addr,
> +			      addrbuf, sizeof(addrbuf)) == NULL)
> +			return;
> +		snprintf(portbuf, sizeof(portbuf), "%hu",
> +			 ntohs(sin_addr->sin_port));
> +#ifndef NO_IPV6
> +	} else if (addr->sa_family == AF_INET6) {
> +		const struct sockaddr_in6 *sin6_addr = (void *)addr;
> +
> +		addrbuf[0] = '[';
> +		addrbuf[1] = '\0';
> +		if (inet_ntop(AF_INET6, &sin6_addr->sin6_addr, addrbuf + 1,
> +			      sizeof(addrbuf) - 2) == NULL)
> +			return;
> +		strcat(addrbuf, "]");
> +
> +		snprintf(portbuf, sizeof(portbuf), "%hu",
> +			 ntohs(sin6_addr->sin6_port));
> +#endif
> +	} else {
> +		snprintf(addrbuf, sizeof(addrbuf), "<AF %d>",
> +			 addr->sa_family);
> +	}
> +	if (setenv("REMOTE_ADDR", addrbuf, true) < 0)
> +		return;
> +	setenv("REMOTE_PORT", portbuf, true);
> +}
> +
>  int main(int argc, char **argv)
>  {
>  	int listen_port = 0;
> @@ -1341,10 +1390,8 @@ int main(int argc, char **argv)
>  		die("base-path '%s' does not exist or is not a directory",
>  		    base_path);
>  
> -	if (inetd_mode) {
> -		if (!freopen("/dev/null", "w", stderr))
> -			die_errno("failed to redirect stderr to /dev/null");
> -	}
> +	if (inetd_mode)
> +		inetd_mode_prepare();
>  
>  	if (inetd_mode || serve_mode)
>  		return execute();