siit: fix compilation warning

Fix compilation warning for stack limit and variable length array.
Fix compilation warning:
  CC [M]  /home/ansuel/openwrt-ansuel/openwrt/build_dir/target-aarch64_cortex-a53_musl/linux-ipq807x_generic/siit-1.2/siit.o
../siit-1.2/siit.c: In function 'ip4_fragment':
../siit-1.2/siit.c:988:9: error: ISO C90 forbids variable length array 'buff' [-Werror=vla]
  988 |         char buff[FRAG_BUFF_SIZE+hdr_len]; /* buffer to form new fragment packet */
      |         ^~~~
../siit-1.2/siit.c: In function 'siit_xmit':
../siit-1.2/siit.c:1359:1: error: the frame size of 2144 bytes is larger than 1024 bytes [-Werror=frame-larger-than=]
 1359 | }
      | ^
cc1: all warnings being treated as errors

Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>

diff --git a/net/siit/src/siit.c b/net/siit/src/siit.c
index 16bb02492da6ff3aac0b96c4098537544fcd38d3..8a7350b8d5327cc3ba9448dafdcbc0d48fa2a212 100644 (file)
--- a/net/siit/src/siit.c
+++ b/net/siit/src/siit.c
@@ -985,10 +985,10 @@ static int ip6_ip4(char *src, int len, char *dst, int include_flag)
 static int ip4_fragment(struct sk_buff *skb, int len, int hdr_len, struct net_device *dev, struct ethhdr *eth_h)
 {
        struct sk_buff *skb2 = NULL;       /* pointer to new struct sk_buff for transleded packet */
-       char buff[FRAG_BUFF_SIZE+hdr_len]; /* buffer to form new fragment packet */
+       char *buff; /* buffer to form new fragment packet */
        char *cur_ptr = skb->data+hdr_len; /* pointter to current packet data with len = frag_len */
        struct iphdr *ih4 = (struct iphdr *) skb->data;
-       struct iphdr *new_ih4 = (struct iphdr *) buff; /* point to new IPv4 hdr */
+       struct iphdr *new_ih4; /* point to new IPv4 hdr */
        struct ethhdr *new_eth_h;   /* point to ether hdr, need to set hard header data in fragment */
        int data_len = len - hdr_len; /* origin packet data len */
        int rest_len = data_len;    /* rest data to fragment */
@@ -999,6 +999,8 @@ static int ip4_fragment(struct sk_buff *skb, int len, int hdr_len, struct net_de
        __u16 frag_offset = 0;      /* fragment offset */
        unsigned int csum;
        unsigned short udp_len;
+       int ret = 0;
+
 
 #ifdef SIIT_DEBUG
        printk("siit: it's DF == 0 and result IPv6 packet will be > 1280\n");
@@ -1035,6 +1037,14 @@ static int ip4_fragment(struct sk_buff *skb, int len, int hdr_len, struct net_de
 
        new_id = ih4->id;
 
+       buff = kcalloc(FRAG_BUFF_SIZE+hdr_len, sizeof(*buff), GFP_KERNEL);
+       if (!buff) {
+               printk("siit: Failed to allocate buf\n");
+               return -1;
+       }
+
+       new_ih4 = (struct iphdr *) buff;
+
        while(1) {
                if (rest_len <= FRAG_BUFF_SIZE) {
                        /* it's last fragmen */
@@ -1072,7 +1082,8 @@ static int ip4_fragment(struct sk_buff *skb, int len, int hdr_len, struct net_de
                if (!skb2) {
                        printk(KERN_DEBUG "%s: alloc_skb failure - packet dropped.\n", dev->name);
                        dev_kfree_skb(skb2);
-                       return -1;
+                       ret = -1;
+                       goto exit;
                }
                /* allocate skb->data portion for IP header len, fragment data len and ether header len
                 * and copy to head ether header from origin skb
@@ -1094,7 +1105,8 @@ static int ip4_fragment(struct sk_buff *skb, int len, int hdr_len, struct net_de
                /* call translation function */
                if ( ip4_ip6(buff, frag_len+hdr_len, skb2->data, 0) == -1) {
                        dev_kfree_skb(skb2);
-                       return -1;
+                       ret = -1;
+                       goto exit;
                }
 
                /*
@@ -1123,7 +1135,9 @@ static int ip4_fragment(struct sk_buff *skb, int len, int hdr_len, struct net_de
                frag_offset = (frag_offset*8 + frag_len)/8;
        }
 
-       return 0;
+exit:
+       kfree(buff);
+       return ret;
 }
 /*
  * Transmit a packet (called by the kernel)
@@ -1156,7 +1170,6 @@ static int siit_xmit(struct sk_buff *skb, struct net_device *dev)
        int len;                    /* original packets length */
        int new_packet_len;
        int skb_delta = 0;          /* delta size for allocate new skb */
-       char new_packet_buff[2048];
 
        /* Check pointer to sk_buff and device structs */
        if (skb == NULL || dev == NULL)
@@ -1303,6 +1316,14 @@ static int siit_xmit(struct sk_buff *skb, struct net_device *dev)
         * IPv6 paket
         */
        else if (ntohs(skb->protocol) == ETH_P_IPV6) {
+               char *new_packet_buff;
+
+               new_packet_buff = kcalloc(2048, sizeof(*new_packet_buff), GFP_KERNEL);
+               if (!new_packet_buff) {
+                       printk(KERN_DEBUG "%s: alloc new_packet_buff failure, packet dropped.\n", dev->name);
+                       siit_stats(dev)->rx_dropped++;
+                       goto end;
+               }
 
 #ifdef SIIT_DEBUG
                siit_print_dump(skb->data, sizeof(struct ipv6hdr), "siit: (in) ip6_hdr dump");
@@ -1315,6 +1336,7 @@ static int siit_xmit(struct sk_buff *skb, struct net_device *dev)
                {
                        PDEBUG("siit_xmit(): error translation ipv6->ipv4, packet dropped.\n");
                        siit_stats(dev)->rx_dropped++;
+                       kfree(new_packet_buff);
                        goto end;
                }
 
@@ -1323,6 +1345,7 @@ static int siit_xmit(struct sk_buff *skb, struct net_device *dev)
                if (!skb2) {
                        printk(KERN_DEBUG "%s: alloc_skb failure, packet dropped.\n", dev->name);
                        siit_stats(dev)->rx_dropped++;
+                       kfree(new_packet_buff);
                        goto end;
                }
                memcpy(skb_put(skb2, new_packet_len + dev->hard_header_len), (char *)eth_h, dev->hard_header_len);