Author: pjd
Date: Wed Jul 3 21:04:20 2013
New Revision: 252603
URL: http://svnweb.freebsd.org/changeset/base/252603
Log:
The whole sending functionality was implemented within signal handler,
which is very bad idea. Split sending and receiving in two processes,
which fixes this problem and will help to sandbox rwhod.
Submitted by: Mariusz Zaborski <osho...@freebsd.org>
Sponsored by: Google Summer of Code 2013
Reviewed by: pjd
MFC after: 1 month
Modified:
head/usr.sbin/rwhod/rwhod.c
Modified: head/usr.sbin/rwhod/rwhod.c
==============================================================================
--- head/usr.sbin/rwhod/rwhod.c Wed Jul 3 20:58:58 2013 (r252602)
+++ head/usr.sbin/rwhod/rwhod.c Wed Jul 3 21:04:20 2013 (r252603)
@@ -1,5 +1,6 @@
/*-
* Copyright (c) 1983, 1993 The Regents of the University of California.
+ * Copyright (c) 2013 Mariusz Zaborski <osho...@freebsd.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
@@ -48,6 +49,8 @@ __FBSDID("$FreeBSD$");
#include <sys/signal.h>
#include <sys/ioctl.h>
#include <sys/sysctl.h>
+#include <sys/procdesc.h>
+#include <sys/wait.h>
#include <net/if.h>
#include <net/if_dl.h>
@@ -93,10 +96,10 @@ struct sockaddr_in multicast_addr =
{ sizeof(multicast_addr), AF_INET, 0, { 0 }, { 0 } };
/*
- * Alarm interval. Don't forget to change the down time check in ruptime
+ * Sleep interval. Don't forget to change the down time check in ruptime
* if this is changed.
*/
-#define AL_INTERVAL (3 * 60)
+#define SL_INTERVAL (3 * 60)
char myname[MAXHOSTNAMELEN];
@@ -117,15 +120,18 @@ struct neighbor *neighbors;
struct whod mywd;
struct servent *sp;
int s;
+int fdp;
+pid_t pid_child_receiver;
#define WHDRSIZE (int)(sizeof(mywd) - sizeof(mywd.wd_we))
int configure(int so);
void getboottime(int signo __unused);
-void onalrm(int signo __unused);
+void receiver_process(void);
void rt_xaddrs(caddr_t cp, caddr_t cplim, struct rt_addrinfo *rtinfo);
void run_as(uid_t *uid, gid_t *gid);
void quit(const char *msg);
+void sender_process(void);
int verify(char *name, int maxlen);
static void usage(void);
@@ -168,9 +174,6 @@ void Sendto(int s, const void *buf, size
int
main(int argc, char *argv[])
{
- struct sockaddr_in from;
- struct stat st;
- char path[64];
int on;
char *cp;
struct sockaddr_in soin;
@@ -269,16 +272,83 @@ main(int argc, char *argv[])
if (!configure(s))
exit(1);
if (!quiet_mode) {
- signal(SIGALRM, onalrm);
- onalrm(0);
+ pid_child_receiver = pdfork(&fdp, 0);
+ if (pid_child_receiver == 0) {
+ receiver_process();
+ } else if (pid_child_receiver > 0) {
+ sender_process();
+ } else if (pid_child_receiver == -1) {
+ syslog(LOG_ERR, "pdfork: %m");
+ exit(1);
+ }
+ } else {
+ receiver_process();
}
- for (;;) {
- struct whod wd;
- socklen_t len;
- int cc, whod;
- time_t t;
+}
+
+static void
+usage(void)
+{
+
+ fprintf(stderr, "usage: rwhod [-i] [-p] [-l] [-m [ttl]]\n");
+ exit(1);
+}
+
+void
+run_as(uid_t *uid, gid_t *gid)
+{
+ struct passwd *pw;
+ struct group *gr;
+
+ pw = getpwnam(UNPRIV_USER);
+ if (pw == NULL) {
+ syslog(LOG_ERR, "getpwnam(%s): %m", UNPRIV_USER);
+ exit(1);
+ }
+ *uid = pw->pw_uid;
+
+ gr = getgrnam(UNPRIV_GROUP);
+ if (gr == NULL) {
+ syslog(LOG_ERR, "getgrnam(%s): %m", UNPRIV_GROUP);
+ exit(1);
+ }
+ *gid = gr->gr_gid;
+}
+
+/*
+ * Check out host name for unprintables
+ * and other funnies before allowing a file
+ * to be created. Sorry, but blanks aren't allowed.
+ */
+int
+verify(char *name, int maxlen)
+{
+ int size;
+
+ size = 0;
+ while (*name != '\0' && size < maxlen - 1) {
+ if (!isascii(*name) || !isalnum(*name) || ispunct(*name))
+ return (0);
+ name++;
+ size++;
+ }
+ *name = '\0';
+ return (size > 0);
+}
+
+void
+receiver_process(void)
+{
+ struct sockaddr_in from;
+ struct stat st;
+ char path[64];
+ struct whod wd;
+ socklen_t len;
+ int cc, whod;
+ time_t t;
- len = sizeof(from);
+ len = sizeof(from);
+ for (;;) {
cc = recvfrom(s, &wd, sizeof(wd), 0, (struct sockaddr *)&from,
&len);
if (cc <= 0) {
@@ -344,139 +414,97 @@ main(int argc, char *argv[])
}
}
-static void
-usage(void)
-{
-
- fprintf(stderr, "usage: rwhod [-i] [-p] [-l] [-m [ttl]]\n");
- exit(1);
-}
-
-void
-run_as(uid_t *uid, gid_t *gid)
-{
- struct passwd *pw;
- struct group *gr;
-
- pw = getpwnam(UNPRIV_USER);
- if (pw == NULL) {
- syslog(LOG_ERR, "getpwnam(%s): %m", UNPRIV_USER);
- exit(1);
- }
- *uid = pw->pw_uid;
-
- gr = getgrnam(UNPRIV_GROUP);
- if (gr == NULL) {
- syslog(LOG_ERR, "getgrnam(%s): %m", UNPRIV_GROUP);
- exit(1);
- }
- *gid = gr->gr_gid;
-}
-
-/*
- * Check out host name for unprintables
- * and other funnies before allowing a file
- * to be created. Sorry, but blanks aren't allowed.
- */
-int
-verify(char *name, int maxlen)
-{
- int size;
-
- size = 0;
- while (*name != '\0' && size < maxlen - 1) {
- if (!isascii(*name) || !isalnum(*name) || ispunct(*name))
- return (0);
- name++;
- size++;
- }
- *name = '\0';
- return (size > 0);
-}
-
void
-onalrm(int signo __unused)
+sender_process(void)
{
- static int alarmcount = 0;
+ int sendcount;
double avenrun[3];
time_t now;
- int i, cc;
+ int i, cc, status;
struct utmpx *ut;
struct stat stb;
struct neighbor *np;
struct whoent *we, *wend;
- we = mywd.wd_we;
- now = time(NULL);
- if (alarmcount % 10 == 0)
- getboottime(0);
- alarmcount++;
- wend = &mywd.wd_we[1024 / sizeof(struct whoent)];
- setutxent();
- while ((ut = getutxent()) != NULL && we < wend) {
- if (ut->ut_type != USER_PROCESS)
- continue;
- strncpy(we->we_utmp.out_line, ut->ut_line,
- sizeof(we->we_utmp.out_line));
- strncpy(we->we_utmp.out_name, ut->ut_user,
- sizeof(we->we_utmp.out_name));
- we->we_utmp.out_time =
- htonl(_time_to_time32(ut->ut_tv.tv_sec));
- we++;
- }
- endutxent();
-
- if (chdir(_PATH_DEV) < 0) {
- syslog(LOG_ERR, "chdir(%s): %m", _PATH_DEV);
- exit(1);
- }
- wend = we;
- for (we = mywd.wd_we; we < wend; we++) {
- if (stat(we->we_utmp.out_line, &stb) >= 0)
- we->we_idle = htonl(now - stb.st_atime);
- we++;
- }
- (void) getloadavg(avenrun, sizeof(avenrun) / sizeof(avenrun[0]));
- for (i = 0; i < 3; i++)
- mywd.wd_loadav[i] = htonl((u_long)(avenrun[i] * 100));
- cc = (char *)wend - (char *)&mywd;
- mywd.wd_sendtime = htonl(_time_to_time32(time(NULL)));
- mywd.wd_vers = WHODVERSION;
- mywd.wd_type = WHODTYPE_STATUS;
- if (multicast_mode == SCOPED_MULTICAST) {
- (void) sendto(s, (char *)&mywd, cc, 0,
- (struct sockaddr *)&multicast_addr,
- sizeof(multicast_addr));
- } else {
- for (np = neighbors; np != NULL; np = np->n_next) {
- if (multicast_mode == PER_INTERFACE_MULTICAST &&
- (np->n_flags & IFF_MULTICAST) != 0) {
- /*
- * Select the outgoing interface for the
- * multicast.
- */
- if (setsockopt(s, IPPROTO_IP,
- IP_MULTICAST_IF,
- &(((struct sockaddr_in
*)np->n_addr)->sin_addr),
- sizeof(struct in_addr)) < 0) {
- syslog(LOG_ERR,
- "setsockopt IP_MULTICAST_IF: %m");
- exit(1);
+ sendcount = 0;
+ for (;;) {
+ we = mywd.wd_we;
+ now = time(NULL);
+ if (sendcount % 10 == 0)
+ getboottime(0);
+ sendcount++;
+ wend = &mywd.wd_we[1024 / sizeof(struct whoent)];
+ setutxent();
+ while ((ut = getutxent()) != NULL && we < wend) {
+ if (ut->ut_type != USER_PROCESS)
+ continue;
+ strncpy(we->we_utmp.out_line, ut->ut_line,
+ sizeof(we->we_utmp.out_line));
+ strncpy(we->we_utmp.out_name, ut->ut_user,
+ sizeof(we->we_utmp.out_name));
+ we->we_utmp.out_time =
+ htonl(_time_to_time32(ut->ut_tv.tv_sec));
+ we++;
+ }
+ endutxent();
+
+ if (chdir(_PATH_DEV) < 0) {
+ syslog(LOG_ERR, "chdir(%s): %m", _PATH_DEV);
+ exit(1);
+ }
+ wend = we;
+ for (we = mywd.wd_we; we < wend; we++) {
+ if (stat(we->we_utmp.out_line, &stb) >= 0)
+ we->we_idle = htonl(now - stb.st_atime);
+ we++;
+ }
+ (void) getloadavg(avenrun,
+ sizeof(avenrun) / sizeof(avenrun[0]));
+ for (i = 0; i < 3; i++)
+ mywd.wd_loadav[i] = htonl((u_long)(avenrun[i] * 100));
+ cc = (char *)wend - (char *)&mywd;
+ mywd.wd_sendtime = htonl(_time_to_time32(time(NULL)));
+ mywd.wd_vers = WHODVERSION;
+ mywd.wd_type = WHODTYPE_STATUS;
+ if (multicast_mode == SCOPED_MULTICAST) {
+ (void) sendto(s, (char *)&mywd, cc, 0,
+ (struct sockaddr *)&multicast_addr,
+ sizeof(multicast_addr));
+ } else {
+ for (np = neighbors; np != NULL; np = np->n_next) {
+ if (multicast_mode == PER_INTERFACE_MULTICAST &&
+ (np->n_flags & IFF_MULTICAST) != 0) {
+ /*
+ * Select the outgoing interface for the
+ * multicast.
+ */
+ if (setsockopt(s, IPPROTO_IP,
+ IP_MULTICAST_IF,
+ &(((struct sockaddr_in
*)np->n_addr)->sin_addr),
+ sizeof(struct in_addr)) < 0) {
+ syslog(LOG_ERR,
+ "setsockopt
IP_MULTICAST_IF: %m");
+ exit(1);
+ }
+ (void) sendto(s, (char *)&mywd, cc, 0,
+ (struct sockaddr *)&multicast_addr,
+ sizeof(multicast_addr));
+ } else {
+ (void) sendto(s, (char *)&mywd, cc, 0,
+ np->n_addr, np->n_addrlen);
}
- (void) sendto(s, (char *)&mywd, cc, 0,
- (struct sockaddr *)&multicast_addr,
- sizeof(multicast_addr));
- } else {
- (void) sendto(s, (char *)&mywd, cc, 0,
- np->n_addr, np->n_addrlen);
}
}
+ if (chdir(_PATH_RWHODIR) < 0) {
+ syslog(LOG_ERR, "chdir(%s): %m", _PATH_RWHODIR);
+ exit(1);
+ }
+ if (waitpid(pid_child_receiver, &status, WNOHANG) ==
+ pid_child_receiver) {
+ break;
+ }
+ sleep(SL_INTERVAL);
}
- if (chdir(_PATH_RWHODIR) < 0) {
- syslog(LOG_ERR, "chdir(%s): %m", _PATH_RWHODIR);
- exit(1);
- }
- (void) alarm(AL_INTERVAL);
}
void
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