ipv4: snmp: do not use SNMP_MIB_SENTINEL anymore

Use ARRAY_SIZE(), so that we know the limit at compile time.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Sabrina Dubroca <sd@queasysnail.net>
Link: https://patch.msgid.link/20250905165813.1470708-5-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/net/ipv4/proc.c b/net/ipv4/proc.c
index 65b0d0ab0084029db43135a91da6eeb1f1fba024..974afc4ecbe2edaae08d98c7b5988ec49bc099f9 100644 (file)
--- a/net/ipv4/proc.c
+++ b/net/ipv4/proc.c
@@ -95,7 +95,6 @@ static const struct snmp_mib snmp4_ipstats_list[] = {
        SNMP_MIB_ITEM("FragFails", IPSTATS_MIB_FRAGFAILS),
        SNMP_MIB_ITEM("FragCreates", IPSTATS_MIB_FRAGCREATES),
        SNMP_MIB_ITEM("OutTransmits", IPSTATS_MIB_OUTPKTS),
-       SNMP_MIB_SENTINEL
 };
 
 /* Following items are displayed in /proc/net/netstat */
@@ -119,7 +118,6 @@ static const struct snmp_mib snmp4_ipextstats_list[] = {
        SNMP_MIB_ITEM("InECT0Pkts", IPSTATS_MIB_ECT0PKTS),
        SNMP_MIB_ITEM("InCEPkts", IPSTATS_MIB_CEPKTS),
        SNMP_MIB_ITEM("ReasmOverlaps", IPSTATS_MIB_REASM_OVERLAPS),
-       SNMP_MIB_SENTINEL
 };
 
 static const struct {
@@ -157,7 +155,6 @@ static const struct snmp_mib snmp4_tcp_list[] = {
        SNMP_MIB_ITEM("InErrs", TCP_MIB_INERRS),
        SNMP_MIB_ITEM("OutRsts", TCP_MIB_OUTRSTS),
        SNMP_MIB_ITEM("InCsumErrors", TCP_MIB_CSUMERRORS),
-       SNMP_MIB_SENTINEL
 };
 
 static const struct snmp_mib snmp4_udp_list[] = {
@@ -170,7 +167,6 @@ static const struct snmp_mib snmp4_udp_list[] = {
        SNMP_MIB_ITEM("InCsumErrors", UDP_MIB_CSUMERRORS),
        SNMP_MIB_ITEM("IgnoredMulti", UDP_MIB_IGNOREDMULTI),
        SNMP_MIB_ITEM("MemErrors", UDP_MIB_MEMERRORS),
-       SNMP_MIB_SENTINEL
 };
 
 static const struct snmp_mib snmp4_net_list[] = {
@@ -309,7 +305,6 @@ static const struct snmp_mib snmp4_net_list[] = {
        SNMP_MIB_ITEM("TCPAOKeyNotFound", LINUX_MIB_TCPAOKEYNOTFOUND),
        SNMP_MIB_ITEM("TCPAOGood", LINUX_MIB_TCPAOGOOD),
        SNMP_MIB_ITEM("TCPAODroppedIcmps", LINUX_MIB_TCPAODROPPEDICMPS),
-       SNMP_MIB_SENTINEL
 };
 
 static void icmpmsg_put_line(struct seq_file *seq, unsigned long *vals,
@@ -389,14 +384,15 @@ static void icmp_put(struct seq_file *seq)
  */
 static int snmp_seq_show_ipstats(struct seq_file *seq, void *v)
 {
+       const int cnt = ARRAY_SIZE(snmp4_ipstats_list);
+       u64 buff64[ARRAY_SIZE(snmp4_ipstats_list)];
        struct net *net = seq->private;
-       u64 buff64[IPSTATS_MIB_MAX];
        int i;
 
-       memset(buff64, 0, IPSTATS_MIB_MAX * sizeof(u64));
+       memset(buff64, 0, sizeof(buff64));
 
        seq_puts(seq, "Ip: Forwarding DefaultTTL");
-       for (i = 0; snmp4_ipstats_list[i].name; i++)
+       for (i = 0; i < cnt; i++)
                seq_printf(seq, " %s", snmp4_ipstats_list[i].name);
 
        seq_printf(seq, "\nIp: %d %d",
@@ -404,10 +400,10 @@ static int snmp_seq_show_ipstats(struct seq_file *seq, void *v)
                   READ_ONCE(net->ipv4.sysctl_ip_default_ttl));
 
        BUILD_BUG_ON(offsetof(struct ipstats_mib, mibs) != 0);
-       snmp_get_cpu_field64_batch(buff64, snmp4_ipstats_list,
-                                  net->mib.ip_statistics,
-                                  offsetof(struct ipstats_mib, syncp));
-       for (i = 0; snmp4_ipstats_list[i].name; i++)
+       snmp_get_cpu_field64_batch_cnt(buff64, snmp4_ipstats_list, cnt,
+                                      net->mib.ip_statistics,
+                                      offsetof(struct ipstats_mib, syncp));
+       for (i = 0; i < cnt; i++)
                seq_printf(seq, " %llu", buff64[i]);
 
        return 0;
@@ -415,20 +411,23 @@ static int snmp_seq_show_ipstats(struct seq_file *seq, void *v)
 
 static int snmp_seq_show_tcp_udp(struct seq_file *seq, void *v)
 {
+       const int udp_cnt = ARRAY_SIZE(snmp4_udp_list);
+       const int tcp_cnt = ARRAY_SIZE(snmp4_tcp_list);
        unsigned long buff[TCPUDP_MIB_MAX];
        struct net *net = seq->private;
        int i;
 
-       memset(buff, 0, TCPUDP_MIB_MAX * sizeof(unsigned long));
+       memset(buff, 0, tcp_cnt * sizeof(unsigned long));
 
        seq_puts(seq, "\nTcp:");
-       for (i = 0; snmp4_tcp_list[i].name; i++)
+       for (i = 0; i < tcp_cnt; i++)
                seq_printf(seq, " %s", snmp4_tcp_list[i].name);
 
        seq_puts(seq, "\nTcp:");
-       snmp_get_cpu_field_batch(buff, snmp4_tcp_list,
-                                net->mib.tcp_statistics);
-       for (i = 0; snmp4_tcp_list[i].name; i++) {
+       snmp_get_cpu_field_batch_cnt(buff, snmp4_tcp_list,
+                                    tcp_cnt,
+                                    net->mib.tcp_statistics);
+       for (i = 0; i < tcp_cnt; i++) {
                /* MaxConn field is signed, RFC 2012 */
                if (snmp4_tcp_list[i].entry == TCP_MIB_MAXCONN)
                        seq_printf(seq, " %ld", buff[i]);
@@ -436,27 +435,29 @@ static int snmp_seq_show_tcp_udp(struct seq_file *seq, void *v)
                        seq_printf(seq, " %lu", buff[i]);
        }
 
-       memset(buff, 0, TCPUDP_MIB_MAX * sizeof(unsigned long));
+       memset(buff, 0, udp_cnt * sizeof(unsigned long));
 
-       snmp_get_cpu_field_batch(buff, snmp4_udp_list,
-                                net->mib.udp_statistics);
+       snmp_get_cpu_field_batch_cnt(buff, snmp4_udp_list,
+                                    udp_cnt,
+                                    net->mib.udp_statistics);
        seq_puts(seq, "\nUdp:");
-       for (i = 0; snmp4_udp_list[i].name; i++)
+       for (i = 0; i < udp_cnt; i++)
                seq_printf(seq, " %s", snmp4_udp_list[i].name);
        seq_puts(seq, "\nUdp:");
-       for (i = 0; snmp4_udp_list[i].name; i++)
+       for (i = 0; i < udp_cnt; i++)
                seq_printf(seq, " %lu", buff[i]);
 
-       memset(buff, 0, TCPUDP_MIB_MAX * sizeof(unsigned long));
+       memset(buff, 0, udp_cnt * sizeof(unsigned long));
 
        /* the UDP and UDP-Lite MIBs are the same */
        seq_puts(seq, "\nUdpLite:");
-       snmp_get_cpu_field_batch(buff, snmp4_udp_list,
-                                net->mib.udplite_statistics);
-       for (i = 0; snmp4_udp_list[i].name; i++)
+       snmp_get_cpu_field_batch_cnt(buff, snmp4_udp_list,
+                                    udp_cnt,
+                                    net->mib.udplite_statistics);
+       for (i = 0; i < udp_cnt; i++)
                seq_printf(seq, " %s", snmp4_udp_list[i].name);
        seq_puts(seq, "\nUdpLite:");
-       for (i = 0; snmp4_udp_list[i].name; i++)
+       for (i = 0; i < udp_cnt; i++)
                seq_printf(seq, " %lu", buff[i]);
 
        seq_putc(seq, '\n');
@@ -480,8 +481,8 @@ static int snmp_seq_show(struct seq_file *seq, void *v)
  */
 static int netstat_seq_show(struct seq_file *seq, void *v)
 {
-       const int ip_cnt = ARRAY_SIZE(snmp4_ipextstats_list) - 1;
-       const int tcp_cnt = ARRAY_SIZE(snmp4_net_list) - 1;
+       const int ip_cnt = ARRAY_SIZE(snmp4_ipextstats_list);
+       const int tcp_cnt = ARRAY_SIZE(snmp4_net_list);
        struct net *net = seq->private;
        unsigned long *buff;
        int i;
@@ -494,8 +495,8 @@ static int netstat_seq_show(struct seq_file *seq, void *v)
        buff = kzalloc(max(tcp_cnt * sizeof(long), ip_cnt * sizeof(u64)),
                       GFP_KERNEL);
        if (buff) {
-               snmp_get_cpu_field_batch(buff, snmp4_net_list,
-                                        net->mib.net_statistics);
+               snmp_get_cpu_field_batch_cnt(buff, snmp4_net_list, tcp_cnt,
+                                            net->mib.net_statistics);
                for (i = 0; i < tcp_cnt; i++)
                        seq_printf(seq, " %lu", buff[i]);
        } else {
@@ -513,7 +514,7 @@ static int netstat_seq_show(struct seq_file *seq, void *v)
                u64 *buff64 = (u64 *)buff;
 
                memset(buff64, 0, ip_cnt * sizeof(u64));
-               snmp_get_cpu_field64_batch(buff64, snmp4_ipextstats_list,
+               snmp_get_cpu_field64_batch_cnt(buff64, snmp4_ipextstats_list, ip_cnt,
                                           net->mib.ip_statistics,
                                           offsetof(struct ipstats_mib, syncp));
                for (i = 0; i < ip_cnt; i++)