ebpf: Updated eBPF program and skeleton.

Updated section name, so libbpf should init/gues proper
program type without specifications during open/load.
Also, added map_flags with explicitly declared BPF_F_MMAPABLE.
Added check for BPF_F_MMAPABLE flag to meson script and
requirements to libbpf version.
Also changed fragmentation flag check - some TCP/UDP packets
may be considered fragmented if DF flag is set.

Signed-off-by: Andrew Melnychenko <andrew@daynix.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>

meson.build

@@ -2006,19 +2006,23 @@ elif get_option('vduse_blk_export').disabled()
 endif
 
 # libbpf
-libbpf = dependency('libbpf', required: get_option('bpf'), method: 'pkg-config')
+bpf_version = '1.1.0'
+libbpf = dependency('libbpf', version: '>=' + bpf_version, required: get_option('bpf'), method: 'pkg-config')
 if libbpf.found() and not cc.links('''
    #include <bpf/libbpf.h>
+   #include <linux/bpf.h>
    int main(void)
    {
+     // check flag availability
+     int flag = BPF_F_MMAPABLE;
      bpf_object__destroy_skeleton(NULL);
      return 0;
    }''', dependencies: libbpf)
   libbpf = not_found
   if get_option('bpf').enabled()
-    error('libbpf skeleton test failed')
+    error('libbpf skeleton/mmaping test failed')
   else
-    warning('libbpf skeleton test failed, disabling')
+    warning('libbpf skeleton/mmaping test failed, disabling')
   endif
 endif
 

tools/ebpf/rss.bpf.c

@@ -81,6 +81,7 @@ struct {
     __uint(key_size, sizeof(__u32));
     __uint(value_size, sizeof(struct rss_config_t));
     __uint(max_entries, 1);
+    __uint(map_flags, BPF_F_MMAPABLE);
 } tap_rss_map_configurations SEC(".maps");
 
 struct {
@@ -88,6 +89,7 @@ struct {
     __uint(key_size, sizeof(__u32));
     __uint(value_size, sizeof(struct toeplitz_key_data_t));
     __uint(max_entries, 1);
+    __uint(map_flags, BPF_F_MMAPABLE);
 } tap_rss_map_toeplitz_key SEC(".maps");
 
 struct {
@@ -95,6 +97,7 @@ struct {
     __uint(key_size, sizeof(__u32));
     __uint(value_size, sizeof(__u16));
     __uint(max_entries, INDIRECTION_TABLE_SIZE);
+    __uint(map_flags, BPF_F_MMAPABLE);
 } tap_rss_map_indirection_table SEC(".maps");
 
 static inline void net_rx_rss_add_chunk(__u8 *rss_input, size_t *bytes_written,
@@ -317,7 +320,7 @@ static inline int parse_packet(struct __sk_buff *skb,
 
         info->in_src = ip.saddr;
         info->in_dst = ip.daddr;
-        info->is_fragmented = !!ip.frag_off;
+        info->is_fragmented = !!(bpf_ntohs(ip.frag_off) & (0x2000 | 0x1fff));
 
         l4_protocol = ip.protocol;
         l4_offset = ip.ihl * 4;
@@ -528,7 +531,7 @@ static inline __u32 calculate_rss_hash(struct __sk_buff *skb,
     return result;
 }
 
-SEC("tun_rss_steering")
+SEC("socket")
 int tun_rss_steering_prog(struct __sk_buff *skb)
 {