Switch the state variables to track the buffer size for the sysctl to
size_t and stop using the somewhat strange way of working with the buf
limit from starting with a negative w_needed. Just use the less confusing
w_needed <= w_given as limit check.
--
:wq Claudio
Index: net/rtsock.c
===================================================================
RCS file: /cvs/src/sys/net/rtsock.c,v
retrieving revision 1.329
diff -u -p -r1.329 rtsock.c
--- net/rtsock.c 16 Jun 2022 10:35:45 -0000 1.329
+++ net/rtsock.c 24 Jun 2022 12:03:54 -0000
@@ -101,7 +101,8 @@
const struct sockaddr route_src = { 2, PF_ROUTE, };
struct walkarg {
- int w_op, w_arg, w_given, w_needed, w_tmemsize;
+ int w_op, w_arg, w_tmemsize;
+ size_t w_given, w_needed;
caddr_t w_where, w_tmem;
};
@@ -1660,7 +1661,7 @@ again:
len = ALIGN(len);
if (cp == 0 && w != NULL && !second_time) {
w->w_needed += len;
- if (w->w_needed <= 0 && w->w_where) {
+ if (w->w_needed <= w->w_given && w->w_where) {
if (w->w_tmemsize < len) {
free(w->w_tmem, M_RTABLE, w->w_tmemsize);
w->w_tmem = malloc(len, M_RTABLE,
@@ -1983,7 +1984,7 @@ sysctl_dumpentry(struct rtentry *rt, voi
#endif
size = rtm_msg2(RTM_GET, RTM_VERSION, &info, NULL, w);
- if (w->w_where && w->w_tmem && w->w_needed <= 0) {
+ if (w->w_where && w->w_tmem && w->w_needed <= w->w_given) {
struct rt_msghdr *rtm = (struct rt_msghdr *)w->w_tmem;
rtm->rtm_pid = curproc->p_p->ps_pid;
@@ -2021,7 +2022,7 @@ sysctl_iflist(int af, struct walkarg *w)
/* Copy the link-layer address first */
info.rti_info[RTAX_IFP] = sdltosa(ifp->if_sadl);
len = rtm_msg2(RTM_IFINFO, RTM_VERSION, &info, 0, w);
- if (w->w_where && w->w_tmem && w->w_needed <= 0) {
+ if (w->w_where && w->w_tmem && w->w_needed <= w->w_given) {
struct if_msghdr *ifm;
ifm = (struct if_msghdr *)w->w_tmem;
@@ -2044,7 +2045,8 @@ sysctl_iflist(int af, struct walkarg *w)
info.rti_info[RTAX_NETMASK] = ifa->ifa_netmask;
info.rti_info[RTAX_BRD] = ifa->ifa_dstaddr;
len = rtm_msg2(RTM_NEWADDR, RTM_VERSION, &info, 0, w);
- if (w->w_where && w->w_tmem && w->w_needed <= 0) {
+ if (w->w_where && w->w_tmem &&
+ w->w_needed <= w->w_given) {
struct ifa_msghdr *ifam;
ifam = (struct ifa_msghdr *)w->w_tmem;
@@ -2076,7 +2078,7 @@ sysctl_ifnames(struct walkarg *w)
if (w->w_arg && w->w_arg != ifp->if_index)
continue;
w->w_needed += sizeof(ifn);
- if (w->w_where && w->w_needed <= 0) {
+ if (w->w_where && w->w_needed <= w->w_given) {
memset(&ifn, 0, sizeof(ifn));
ifn.if_index = ifp->if_index;
@@ -2113,7 +2115,7 @@ sysctl_source(int af, u_int tableid, str
return (0);
}
w->w_needed += size;
- if (w->w_where && w->w_needed <= 0) {
+ if (w->w_where && w->w_needed <= w->w_given) {
if ((error = copyout(sa, w->w_where, size)))
return (error);
w->w_where += size;
@@ -2140,7 +2142,6 @@ sysctl_rtable(int *name, u_int namelen,
bzero(&w, sizeof(w));
w.w_where = where;
w.w_given = *given;
- w.w_needed = 0 - w.w_given;
w.w_op = name[1];
w.w_arg = name[2];
@@ -2211,10 +2212,9 @@ sysctl_rtable(int *name, u_int namelen,
break;
}
free(w.w_tmem, M_RTABLE, w.w_tmemsize);
- w.w_needed += w.w_given;
if (where) {
*given = w.w_where - (caddr_t)where;
- if (*given < w.w_needed)
+ if (w.w_needed > w.w_given)
return (ENOMEM);
} else if (w.w_needed == 0) {
*given = 0;
