Add some basic logger framework

Makefile

@@ -3,7 +3,7 @@ BINDIR=		${PREFIX}/sbin
 MANDIR=		${PREFIX}/man/man
 
 PROG=		icbd
-SRCS=		cmd.c dns.c icb.c icbd.c
+SRCS=		cmd.c dns.c icb.c icbd.c logger.c
 MAN=		icbd.8
 
 CFLAGS+=	-W -Wall -Werror

dns.c

@@ -37,6 +37,7 @@
 
 void dns_dispatch(int, short, void *);
 void dns_done(int, short, void *);
+
 int dns_pipe;
 
 struct icbd_dnsquery {
@@ -122,13 +123,12 @@ dns_dispatch(int fd, short event, void *arg __attribute__((unused)))
 	struct icbd_dnsquery q;
 	int gerr;
 
-	arg = NULL;
 	if (event != EV_READ)
 		return;
 
 	if (read(fd, &q, sizeof q) != sizeof q) {
 		syslog(LOG_ERR, "dns read: %m");
-		exit(1);
+		exit(EX_DATAERR);
 	}
 
 	sa = (struct sockaddr *)&q.u.req;

icb.c

@@ -234,6 +234,8 @@ icb_groupmsg(struct icb_session *is, char *msg)
 	    is->nick, ICB_M_SEP, msg);
 	buf[0] = buflen;
 
+	logger(time(NULL), ig->name, is->nick, msg);
+
 	LIST_FOREACH(s, &ig->sess, entry) {
 		if (s == is)
 			continue;

icbd.c

@@ -211,6 +211,9 @@ main(int argc, char *argv[])
 		return (EX_UNAVAILABLE);
 	}
 
+	/* start the logger service */
+	logger_init();
+
 	/* start a dns resolver thread */
 	dns_init();
 

icbd.h

@@ -30,3 +30,7 @@ time_t	getmonotime(void);
 struct sockaddr_storage;
 int	dns_init(void);
 int	dns_rresolv(struct icb_session *, struct sockaddr_storage *);
+
+/* logger.c */
+int	logger_init(void);
+void	logger(time_t, char *, char *, char *);

logger.c

@@ -0,0 +1,161 @@
+/*
+ * Copyright (c) 2014 Mike Belopuhov
+ * Copyright (c) 2009 Michael Shalayeff
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER IN
+ * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
+ * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <sys/param.h>
+#include <sys/socket.h>
+#include <sys/time.h>
+#include <sys/uio.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <syslog.h>
+#include <sysexits.h>
+#include <login_cap.h>
+#include <event.h>
+#include <pwd.h>
+#include <netdb.h>
+
+#include "icb.h"
+#include "icbd.h"
+
+void logger_dispatch(int, short, void *);
+
+int logger_pipe;
+
+struct icbd_logentry {
+	time_t	timestamp;
+	char	group[ICB_MAXGRPLEN];
+	char	nick[ICB_MAXNICKLEN];
+	size_t	length;
+};
+
+int
+logger_init(void)
+{
+	static struct event ev;
+	struct passwd *pw;
+	int pipes[2];
+
+	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, pipes) == -1) {
+		syslog(LOG_ERR, "socketpair: %m");
+		exit(EX_OSERR);
+	}
+
+	switch (fork()) {
+	case -1:
+		syslog(LOG_ERR, "fork: %m");
+		exit(EX_OSERR);
+	case 0:
+		break;
+
+	default:
+		close(pipes[1]);
+		logger_pipe = pipes[0];
+		return (0);
+	}
+
+	setproctitle("logger");
+	close(pipes[0]);
+
+	if ((pw = getpwnam(ICBD_USER)) == NULL) {
+		syslog(LOG_ERR, "No passwd entry for %s", ICBD_USER);
+		exit(EX_NOUSER);
+	}
+
+	if (setusercontext(NULL, pw, pw->pw_uid,
+	    LOGIN_SETALL & ~LOGIN_SETUSER) < 0)
+		exit(EX_NOPERM);
+
+	if (setuid(pw->pw_uid) < 0) {
+		syslog(LOG_ERR, "%d: %m", pw->pw_uid);
+		exit(EX_NOPERM);
+	}
+
+	if (chdir(pw->pw_dir) < 0) {
+		syslog(LOG_ERR, "chdir: %m");
+		exit(EX_UNAVAILABLE);
+	}
+
+	event_init();
+
+	/* event for message processing */
+	event_set(&ev, pipes[1], EV_READ | EV_PERSIST, logger_dispatch, NULL);
+	if (event_add(&ev, NULL) < 0) {
+		syslog(LOG_ERR, "event_add: %m");
+		exit (EX_UNAVAILABLE);
+	}
+
+	return event_dispatch();
+}
+
+void
+logger_dispatch(int fd, short event, void *arg __attribute__((unused)))
+{
+	char buf[512];
+	struct icbd_logentry e;
+	struct iovec iov[2];
+
+	if (event != EV_READ)
+		return;
+
+	bzero(&e, sizeof e);
+	iov[0].iov_base = &e;
+	iov[0].iov_len = sizeof e;
+
+	iov[1].iov_base = buf;
+	iov[1].iov_len = sizeof buf;
+
+	if (readv(fd, iov, 2) < (ssize_t)sizeof e) {
+		syslog(LOG_ERR, "logger read: %m");
+		exit(EX_DATAERR);
+	}
+
+	/* XXX */
+	if (iov[1].iov_len < e.length) {
+		syslog(LOG_ERR, "logger read %lu out of %lu",
+		    iov[1].iov_len, e.length);
+	}
+
+	/* TODO: check time of the day and open the next file */
+
+	fprintf(stderr, "%s@%s: %s\n", e.nick, e.group, buf);
+}
+
+void
+logger(time_t timestamp, char *group, char *nick, char *what)
+{
+	struct icbd_logentry e;
+	struct iovec iov[2];
+
+	e.timestamp = timestamp;
+	strlcpy(e.group, group, ICB_MAXGRPLEN);
+	strlcpy(e.nick, nick, ICB_MAXNICKLEN);
+	e.length = strlen(what) + 1;
+
+	iov[0].iov_base = &e;
+	iov[0].iov_len = sizeof e;
+
+	iov[1].iov_base = what;
+	iov[1].iov_len = e.length;
+
+	if (writev(logger_pipe, iov, 2) == -1)
+		syslog(LOG_ERR, "logger write: %m");
+}