ffs(3) returns the bit index, not the bit value, and the right-most bit
is index 1. So you need to use
addrs &= ~(1 << (i - 1));
rather than
+ addrs &= ~i;
:)
You could also use
while ((i = ffs(addrs)) != 0) {
...
}
instead of the for(;;) loop.
On Wed, 27 Jan 2016, Martin Husemann wrote:
On Wed, Jan 27, 2016 at 07:53:27PM +0100, Martin Husemann wrote:
How about defining a RTA_ALL_MASK (or however we'd call it, defined as
0x1ff) and write:
for (i = 1; i & RTA_ALL_MASK; i <<= 1) {
?
Or without global header changes, just use ffs() ?
Martin
Index: ifwatchd.c
===================================================================
RCS file: /cvsroot/src/usr.sbin/ifwatchd/ifwatchd.c,v
retrieving revision 1.27
diff -u -p -r1.27 ifwatchd.c
--- ifwatchd.c 27 Jan 2016 18:55:51 -0000 1.27
+++ ifwatchd.c 27 Jan 2016 19:31:10 -0000
@@ -65,7 +65,7 @@ enum event { ARRIVAL, DEPARTURE, UP, DOW
/* local functions */
__dead static void usage(void);
static void dispatch(void*, size_t);
-static void check_addrs(char *cp, int addrs, enum event ev);
+static void check_addrs(char *cp, unsigned int addrs, enum event ev);
static void invoke_script(struct sockaddr *sa, struct sockaddr *dst, enum event
ev, int ifindex, const char *ifname_hint);
static void list_interfaces(const char *ifnames);
static void check_announce(struct if_announcemsghdr *ifan);
@@ -287,32 +287,44 @@ work:
}
static void
-check_addrs(char *cp, int addrs, enum event ev)
+check_addrs(char *cp, unsigned int addrs, enum event ev)
{
struct sockaddr *sa, *ifa = NULL, *brd = NULL;
char ifname_buf[IFNAMSIZ];
const char *ifname;
int ifndx = 0;
- unsigned i;
+ unsigned int i;
if (addrs == 0)
return;
- for (i = 1; i; i <<= 1) {
- if ((i & addrs) == 0)
- continue;
+
+ for (;;) {
+ i = ffs(addrs);
+ if (i == 0)
+ break;
+ addrs &= ~i;
+
sa = (struct sockaddr *)cp;
- if (i == RTA_IFP) {
+ switch (i) {
+ case RTA_IFP:
+ {
struct sockaddr_dl * li = (struct sockaddr_dl*)sa;
ifndx = li->sdl_index;
if (!find_interface(ifndx)) {
if (verbose)
- printf("ignoring change on interface
#%d\n", ifndx);
+ printf("ignoring change on "
+ "interface #%d\n", ifndx);
return;
}
- } else if (i == RTA_IFA)
+ break;
+ }
+ case RTA_IFA:
ifa = sa;
- else if (i == RTA_BRD)
+ break;
+ case RTA_BRD:
brd = sa;
+ break;
+ }
RT_ADVANCE(cp, sa);
}
if (ifa != NULL) {
!DSPAM:56a91bb7142006842815635!
+------------------+--------------------------+------------------------+
| Paul Goyette | PGP Key fingerprint: | E-mail addresses: |
| (Retired) | FA29 0E3B 35AF E8AE 6651 | paul at whooppee.com |
| Kernel Developer | 0786 F758 55DE 53BA 7731 | pgoyette at netbsd.org |
+------------------+--------------------------+------------------------+
