File sysklogd-1.4.1-dns.patch of Package syslogd

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File sysklogd-1.4.1-dns.patch of Package syslogd (Revision 154375ee2abcb4017e666cb226124ad4)

Currently displaying revision 154375ee2abcb4017e666cb226124ad4 , Show latest

---
 Makefile  |    4 
 resolve.c |  249 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 syslogd.c |  139 +++++-----------------------------
 3 files changed, 275 insertions(+), 117 deletions(-)

--- Makefile
+++ Makefile	2022-10-18 06:11:16.691008894 +0000
@@ -79,8 +79,8 @@ test: syslog_tst ksym oops.ko tsyslogd
 
 install: install_man install_exec
 
-syslogd: syslogd.o pidfile.o
-	${CC} ${LDFLAGS} -o syslogd syslogd.o pidfile.o ${LIBS}
+syslogd: syslogd.o pidfile.o resolve.o
+	${CC} ${LDFLAGS} -o syslogd syslogd.o pidfile.o resolve.o ${LIBS}
 
 klogd:	klogd.o syslog.o pidfile.o ksym.o ksym_mod.o
 	${CC} ${LDFLAGS} -o klogd klogd.o syslog.o pidfile.o ksym.o \
--- resolve.c
+++ resolve.c	2022-10-18 06:11:16.691008894 +0000
@@ -0,0 +1,249 @@
+/*
+ * Resolve a hostname
+ *
+ * Copyright (C) 2003, SuSE Linux AG
+ * Written by okir@suse.de
+ */
+
+#include <sys/poll.h>
+#include <netdb.h>
+#include <string.h>
+#include <time.h>
+#include <malloc.h>
+#include <stdlib.h>
+#include <signal.h>
+#include <unistd.h>
+
+#if defined(__GLIBC__)
+#define dprintf mydprintf
+#endif /* __GLIBC__ */
+
+/* Number of times we retry resolving a name */
+#define RESOLVER_RETRIES	10
+/* Timeout between retries to resolve a name */
+#define RESOLVER_RETRY_TIME	(3 * 60)
+/* Time to wait for the sub-process comes up with an
+ * answer, before we suspend the entry */
+#define RESOLVER_WAIT_TIME	5
+
+struct res_name {
+	struct res_name *	next;
+	char *			name;
+	unsigned int		retries;
+	time_t			retry_time;
+	time_t			wait_time;
+	pid_t			process;
+	int			pipe;
+	struct sockaddr_storage	address;
+};
+
+extern void	dprintf(char *fmt, ...);
+static int	do_result(struct res_name *res);
+static void	do_query(int, int, const char *);
+
+static struct res_name *resolve;
+
+int
+resolve_name(const char *name, int family, struct sockaddr_storage *addr)
+{
+	struct res_name	*res;
+	int		fd[2];
+	pid_t		pid;
+	time_t		now;
+
+	time(&now);
+	for (res = resolve; res; res = res->next) {
+		if (!strcmp(res->name, name)) {
+			/* If there's still a sub-process
+			 * attached, see if it came up with an
+			 * answer in the meantime */
+			if (res->pipe >= 0)
+				do_result(res);
+			goto check_result;
+		}
+	}
+
+	res = (struct res_name *) calloc(1, sizeof(*res));
+	res->name = strdup(name);
+	res->retries = RESOLVER_RETRIES;
+	res->retry_time = now + RESOLVER_RETRY_TIME;
+	res->pipe = -1;
+	res->next = resolve;
+	resolve = res;
+
+retry:	res->retries -= 1;
+
+	dprintf("Trying to resolve \"%s\", attempt #%u\n",
+			res->name, RESOLVER_RETRIES - res->retries);
+
+	if (res->pipe >= 0) {
+		/* Make sure resolver subprocess is dead */
+		kill(res->process, SIGKILL);
+		close(res->pipe);
+		res->pipe = -1;
+	}
+
+	signal(SIGCHLD, SIG_IGN);
+	if (pipe(fd) < 0) {
+		/* log error? */
+		return -1;
+	}
+	if ((pid = fork()) < 0) {
+		/* log error? */
+		close(fd[0]);
+		close(fd[1]);
+		return -1;
+	}
+
+	if (pid == 0) {
+		close(fd[0]);
+		do_query(fd[1], family, res->name);
+		/* shouldn't return */
+		exit(1);
+	}
+
+	res->wait_time = now + RESOLVER_WAIT_TIME;
+	res->process = pid;
+	res->pipe = fd[0];
+	close(fd[1]);
+
+	/* Try to collect result within the next couple
+	 * of seconds */
+	do_result(res);
+
+check_result:
+	if (res->pipe >= 0) {
+		dprintf("%s: name resolution not complete, "
+			"waiting for resolver sub-process\n",
+			res->name);
+		return 0;
+	}
+
+	if (res->address.ss_family != AF_UNSPEC) {
+		*addr = res->address;
+		return 1;
+	}
+	if (res->retries == 0) {
+		dprintf("%s: too many failed attempts to resolve hostname, "
+			"given up.\n", res->name);
+		return -1;
+	}
+	if (res->retry_time > now) {
+		dprintf("%s: name resolution failed, "
+			"will retry in %d seconds\n",
+			res->name, res->retry_time - now);
+		return 0;
+	}
+	goto retry;
+}
+
+/*
+ * This function clears the resolver's internal state
+ * when syslogd received a SIGHUP
+ */
+void
+init_resolver(void)
+{
+	struct res_name	*res;
+
+	for (res = resolve; res; res = res->next) {
+		res->address.ss_family = AF_UNSPEC;
+		res->retries = RESOLVER_RETRIES;
+		res->retry_time = 0;
+	}
+}
+
+
+/*
+ * Collect result from sub-process
+ */
+int
+do_result(struct res_name *res)
+{
+	struct sockaddr_storage addr;
+	struct pollfd	_poll;
+	long		wait;
+	int		n;
+
+	if (res->pipe < 0)
+		return 0;
+
+	/* See if we should wait for the subprocess to come
+	 * up with an answer (the initial call to do_result
+	 * after starting the sub-process will always wait for
+	 * a few seconds to avoid losing messages) */
+	if ((wait = res->wait_time - time(NULL)) < 0)
+		wait = 0;
+
+	/* See if we get the resolver's result within the
+	 * next "wait" seconds. If not, let it continue in the
+	 * background */
+	_poll.fd = res->pipe;
+	_poll.events = POLLIN;
+	if (poll(&_poll, 1, wait * 1000) < 1)
+		return 0;
+
+	n = read(res->pipe, &addr, sizeof(addr));
+
+	/* child process has done its duty. */
+	kill(res->process, SIGKILL);
+	close(res->pipe);
+	res->process = 0;
+	res->pipe = -1;
+
+	if (n != sizeof(addr))
+		return -1;
+
+	res->address = addr;
+	if (addr.ss_family != AF_UNSPEC)
+		return 1;
+	return -1;
+}
+
+/*
+ * Sub-process performing lookup
+ */
+void
+do_query(int fd, int family, const char *name)
+{
+	struct sockaddr_storage ss;
+	struct addrinfo hints, *res;
+	int	r;
+
+	memset(&hints, 0, sizeof(hints));
+	hints.ai_socktype = SOCK_DGRAM;
+#ifdef notyet
+	/* XXX - specify AI_whatever for automatic v4-v6 mapping */
+#else
+	hints.ai_family = (family == AF_INET)? family : AF_UNSPEC;
+#endif
+
+	r = getaddrinfo(name, "syslog", &hints, &res);
+	if (r != 0) {
+		dprintf("failed to resolve \"%s\": %s\n",
+				name, gai_strerror(r));
+		exit(1);
+	}
+
+	memset(&ss, 0, sizeof(ss));
+
+	/* Do v4mapped v6 address (supported by recent glibcs
+	 * only) */
+	if (family == AF_INET6 && res->ai_family == AF_INET) {
+		struct sockaddr_in6 *six = (struct sockaddr_in6 *) &ss;
+		struct sockaddr_in  *sin = (struct sockaddr_in *) res->ai_addr;
+
+		six->sin6_family = AF_INET6;
+		six->sin6_port = sin->sin_port;
+		six->sin6_addr.s6_addr16[5] = 0xffff;
+		six->sin6_addr.s6_addr32[3] = sin->sin_addr.s_addr;
+	} else if (res->ai_addrlen > sizeof(ss)) {
+		dprintf("failed to resolve \"%s\": address too large\n",
+				name);
+		exit(1);
+	} else {
+		memcpy(&ss, res->ai_addr, res->ai_addrlen);
+	}
+	write(fd, &ss, sizeof(ss));
+	exit(0);
+}
--- syslogd.c
+++ syslogd.c	2022-10-18 06:17:39.648170295 +0000
@@ -683,14 +683,7 @@ struct filed {
 		struct {
 			char	f_hname[MAXHOSTNAMELEN+1];
 #ifdef INET6
-			union {
-				struct sockaddr		sa;
-				struct sockaddr_in	sin;
-				struct sockaddr_in6	sin6;
-			} f_sa;
-#define f_addr  f_sa.sa
-#define f_addr4 f_sa.sin
-#define f_addr6 f_sa.sin6
+			struct sockaddr_storage	f_addr;
 #else
 			struct sockaddr_in	f_addr;
 #endif
@@ -846,19 +839,17 @@ int decode(char *name, struct code *code
 #if defined(__GLIBC__)
 #define dprintf mydprintf
 #endif /* __GLIBC__ */
-static void dprintf(char *, ...);
+void dprintf(char *, ...);
 static void allocate_log(void);
-void sighup_handler();
+void sighup_handler(int sig);
 
 #ifdef SYSLOG_UNIXAF
 static int create_unix_socket(const char *path);
 #endif
 #ifdef SYSLOG_INET
 static int create_inet_socket();
-#ifdef INET6
-static void setup_inetaddr_all();
-static const char *setup_inetaddr(struct filed *f);
-#endif
+extern int resolve_name(const char *, int, struct sockaddr_storage *);
+extern void init_resolver(void);
 #endif
 
 int main(argc, argv)
@@ -1413,63 +1404,6 @@ static int create_inet_socket()
 	return fd;
 }
 
-#ifdef INET6
-
-static void setup_inetaddr_all()
-{
-	struct filed *f;
-#ifdef SYSV
-	int lognum;
-
-	for (lognum = 0; lognum <= nlogs; lognum++) {
-		f = &Files[lognum];
-#else
-	for (f = Files; f; f = f->f_next) {
-#endif
-		if (f->f_type == F_FORW_UNKN) {
-			if (setup_inetaddr(f)) {
-				f->f_prevcount = INET_RETRY_MAX;
-				f->f_time = time( (time_t *)0 );
-			} else {
-				f->f_type = F_FORW;
-			}
-		}
-	}
-}
-
-static const char *setup_inetaddr(struct filed *f)
-{
-	struct addrinfo hints, *res;
-	int error;
-
-	memset(&hints, 0, sizeof(hints));
-	hints.ai_family = family == AF_INET6 ? AF_UNSPEC : AF_INET;
-	hints.ai_socktype = SOCK_DGRAM;
-	error = getaddrinfo(f->f_un.f_forw.f_hname, "syslog", &hints, &res);
-	if (error) {
-		return gai_strerror(error);
-	}
-	if (res->ai_addrlen > sizeof(f->f_un.f_forw.f_sa)) {
-		freeaddrinfo(res);
-		return "addrlen too large";
-	}
-	if (family == AF_INET6 && res->ai_family == AF_INET) {
-		/* v4mapped addr */
-		f->f_un.f_forw.f_addr.sa_family = AF_INET6;
-		f->f_un.f_forw.f_addr6.sin6_port =
-			((struct sockaddr_in *)res->ai_addr)->sin_port;
-		f->f_un.f_forw.f_addr6.sin6_addr.s6_addr16[5] = 0xffff;
-		memcpy(&f->f_un.f_forw.f_addr6.sin6_addr.s6_addr32[3],
-			&((struct sockaddr_in *)res->ai_addr)->sin_addr,
-			sizeof(struct in_addr));
-	} else {
-		memcpy(&f->f_un.f_forw.f_addr, res->ai_addr, res->ai_addrlen);
-	}
-	freeaddrinfo(res);
-
-	return NULL;
-}
-#endif /* end of INET6 */
 #endif
 
 char **
@@ -1913,7 +1847,7 @@ void fprintlog(f, from, flags, msg)
 	char line[MAXLINE + 1];
 	time_t fwd_suspend;
 #ifdef INET6
-	const char *errmsg;
+	int reserr;
 #else
 	struct hostent *hp;
 #endif
@@ -1982,38 +1916,21 @@ void fprintlog(f, from, flags, msg)
 	 */
 	case F_FORW_UNKN:
 		dprintf(" %s\n", f->f_un.f_forw.f_hname);
-		fwd_suspend = time((time_t *) 0) - f->f_time;
-		if ( fwd_suspend >= INET_SUSPEND_TIME ) {
-			dprintf("Forwarding suspension to unknown over, retrying\n");
-#ifdef INET6
-			if ((errmsg = setup_inetaddr(f))) {
-				dprintf("Failure: %s\n", errmsg);
-#else
-			if ( (hp = gethostbyname(f->f_un.f_forw.f_hname)) == NULL ) {
-				dprintf("Failure: %s\n", sys_h_errlist[h_errno]);
-#endif
-				dprintf("Retries: %d\n", f->f_prevcount);
-				if ( --f->f_prevcount < 0 ) {
-					dprintf("Giving up.\n");
-					f->f_type = F_UNUSED;
-				}
-				else
-					dprintf("Left retries: %d\n", f->f_prevcount);
-			}
-			else {
-			        dprintf("%s found, resuming.\n", f->f_un.f_forw.f_hname);
-#ifndef INET6 /* not */
-				memcpy((char *) &f->f_un.f_forw.f_addr.sin_addr, hp->h_addr, hp->h_length);
-#endif
-				f->f_prevcount = 0;
-				f->f_type = F_FORW;
-				goto f_forw;
-			}
+		reserr = resolve_name(f->f_un.f_forw.f_hname,
+					family,
+					&f->f_un.f_forw.f_addr);
+		if (reserr > 0) {
+			dprintf("Successfully resolved hostname \"%s\"\n", f->f_un.f_forw.f_hname);
+			f->f_type = F_FORW;
+		} else if (reserr < 0) {
+			dprintf("Giving up on hostname \"%s\"\n", f->f_un.f_forw.f_hname);
+			f->f_type = F_UNUSED;
+			break;
+		} else {
+			/* Not yet - query in progress, or suspended */
+			break;
 		}
-		else
-			dprintf("Forwarding suspension not over, time " \
-				"left: %d\n", INET_SUSPEND_TIME - fwd_suspend);
-		break;
+		/* fallthrough */
 
 	case F_FORW:
 		/* 
@@ -2429,9 +2346,7 @@ void logerror(type)
 }
 
 void die(sig)
-
 	int sig;
-	
 {
 	register struct filed *f;
 	char buf[100];
@@ -2655,6 +2570,7 @@ void init()
 #endif
 
 #ifdef SYSLOG_INET
+	init_resolver();
 	if (Forwarding || AcceptRemote) {
 		if (finet < 0) {
 			finet = create_inet_socket();
@@ -2671,10 +2587,6 @@ void init()
 		InetInuse = 0;
 	}
 	inetm = finet;
-#ifdef INET6
-	if (finet >= 0)
-		setup_inetaddr_all();
-#endif
 #endif
 
 	Initialized = 1;
@@ -3040,8 +2952,7 @@ int decode(name, codetab)
 	return (-1);
 }
 
-static void dprintf(char *fmt, ...)
-
+void dprintf(char *fmt, ...)
 {
 	va_list ap;
 
@@ -3061,8 +2972,7 @@ static void dprintf(char *fmt, ...)
  * The following function is responsible for allocating/reallocating the
  * array which holds the structures which define the logging outputs.
  */
-static void allocate_log()
-
+static void allocate_log(void)
 {
 	dprintf("Called allocate_log, nlogs = %d.\n", nlogs);
 	
@@ -3109,8 +3019,7 @@ static void allocate_log()
  * doing this during a signal handler.  Instead this function simply sets
  * a flag variable which will tell the main loop to go through a restart.
  */
-void sighup_handler()
-
+void sighup_handler(int sig)
 {
 	restart = 1;
 	signal(SIGHUP, sighup_handler);

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File sysklogd-1.4.1-dns.patch of Package syslogd (Revision 154375ee2abcb4017e666cb226124ad4)

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