Attachment 203750 Details for Bug 195191 – Retry NET_RT_IFLIST sysctl

[patch] Retry NET_RT_IFLIST sysctl

rtadvd_retry_sysctl_12-RELEASE.patch (text/plain), 2.04 KB, created by guyyur on 2019-04-17 18:48:07 UTC

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Creator: guyyur

Created: 2019-04-17 18:48:07 UTC

Size: 2.04 KB

patch

obsolete

>Index: usr.sbin/rtadvd/if.c
>===================================================================
>--- usr.sbin/rtadvd/if.c	(revision 344217)
>+++ usr.sbin/rtadvd/if.c	(working copy)
>@@ -408,6 +408,7 @@
> 	return (0);
> }
> 
>+#define MAX_SYSCTL_TRY 5
> struct ifinfo *
> update_ifinfo(struct ifilist_head_t *ifi_head, int ifindex)
> {
>@@ -419,27 +420,45 @@
> 	size_t len;
> 	char *lim;
> 	int mib[] = { CTL_NET, PF_ROUTE, 0, AF_INET6, NET_RT_IFLIST, 0 };
>-	int error;
>+	int error, ntry = 0;
> 
> 	syslog(LOG_DEBUG, "<%s> enter", __func__);
> 
>-	if (sysctl(mib, sizeof(mib)/sizeof(mib[0]), NULL, &len, NULL, 0) <
>-	    0) {
>-		syslog(LOG_ERR,
>-		    "<%s> sysctl: NET_RT_IFLIST size get failed", __func__);
>-		exit(1);
>-	}
>-	if ((msg = malloc(len)) == NULL) {
>-		syslog(LOG_ERR, "<%s> malloc failed", __func__);
>-		exit(1);
>-	}
>-	if (sysctl(mib, sizeof(mib)/sizeof(mib[0]), msg, &len, NULL, 0) <
>-	    0) {
>-		syslog(LOG_ERR,
>-		    "<%s> sysctl: NET_RT_IFLIST get failed", __func__);
>-		exit(1);
>-	}
>+	do {
>+		/*
>+		 * We'll try to get addresses several times in case that
>+		 * the number of addresses is unexpectedly increased during
>+		 * the two sysctl calls.  This should rarely happen.
>+		 * Portability note: since FreeBSD does not add margin of
>+		 * memory at the first sysctl, the possibility of failure on
>+		 * the second sysctl call is a bit higher.
>+		 */
> 
>+		if (sysctl(mib, sizeof(mib)/sizeof(mib[0]), NULL, &len, NULL,
>+		    0) < 0) {
>+			syslog(LOG_ERR,
>+			    "<%s> sysctl: NET_RT_IFLIST size get failed",
>+			    __func__);
>+			exit(1);
>+		}
>+		if ((msg = malloc(len)) == NULL) {
>+			syslog(LOG_ERR, "<%s> malloc failed", __func__);
>+			exit(1);
>+		}
>+		if (sysctl(mib, sizeof(mib)/sizeof(mib[0]), msg, &len, NULL,
>+		    0) < 0) {
>+			if (errno != ENOMEM || ++ntry >= MAX_SYSCTL_TRY) {
>+				free(msg);
>+				syslog(LOG_ERR,
>+				    "<%s> sysctl: NET_RT_IFLIST get failed",
>+				    __func__);
>+				exit(1);
>+			}
>+			free(msg);
>+			msg = NULL;
>+		}
>+	} while (msg == NULL);
>+
> 	lim = msg + len;
> 	for (ifm = (struct if_msghdr *)msg;
> 	     ifm != NULL && ifm < (struct if_msghdr *)lim;

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Attachments on bug 195191: 149611 | 203750