bpf: Make union v6addr const where possible

This is mostly to clarify things for callers, but it will also slightly simplify a subsequent commit. Signed-off-by: Paul Chaignon <paul@cilium.io>
cilium · Jun 8, 2022 · 0ea4341 · 0ea4341
1 parent 2d944e9
commit 0ea4341
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Showing 7 changed files with 16 additions and 15 deletions.
diff --git a/bpf/bpf_sock.c b/bpf/bpf_sock.c
@@ -30,7 +30,7 @@ static __always_inline __maybe_unused bool is_v4_loopback(__be32 daddr)
 	return (daddr & bpf_htonl(0x7f000000)) == bpf_htonl(0x7f000000);
 }
 
-static __always_inline __maybe_unused bool is_v6_loopback(union v6addr *daddr)
+static __always_inline __maybe_unused bool is_v6_loopback(const union v6addr *daddr)
 {
 	/* Check for ::1/128, RFC4291. */
 	union v6addr loopback = { .addr[15] = 1, };
@@ -721,7 +721,7 @@ static __always_inline void ctx_set_v6_address(struct bpf_sock_addr *ctx,
 }
 
 static __always_inline __maybe_unused bool
-sock6_skip_xlate(struct lb6_service *svc, union v6addr *address)
+sock6_skip_xlate(struct lb6_service *svc, const union v6addr *address)
 {
 	if (lb6_to_lb4_service(svc))
 		return true;

diff --git a/bpf/lib/eps.h b/bpf/lib/eps.h
@@ -21,7 +21,7 @@ __lookup_ip6_endpoint(const union v6addr *ip6)
 }
 
 static __always_inline __maybe_unused struct endpoint_info *
-lookup_ip6_endpoint(struct ipv6hdr *ip6)
+lookup_ip6_endpoint(const struct ipv6hdr *ip6)
 {
 	return __lookup_ip6_endpoint((union v6addr *)&ip6->daddr);
 }
@@ -116,8 +116,8 @@ _Pragma("unroll")							\
 	return NULL;							\
 }
 #ifdef IPCACHE6_PREFIXES
-LPM_LOOKUP_FN(lookup_ip6_remote_endpoint, union v6addr *, IPCACHE6_PREFIXES,
-	      IPCACHE_MAP, ipcache_lookup6)
+LPM_LOOKUP_FN(lookup_ip6_remote_endpoint, const union v6addr *,
+	      IPCACHE6_PREFIXES, IPCACHE_MAP, ipcache_lookup6)
 #endif
 #ifdef IPCACHE4_PREFIXES
 LPM_LOOKUP_FN(lookup_ip4_remote_endpoint, __be32, IPCACHE4_PREFIXES,

diff --git a/bpf/lib/ipv6.h b/bpf/lib/ipv6.h
@@ -182,8 +182,8 @@ static __always_inline int ipv6_load_daddr(struct __ctx_buff *ctx, int off,
 }
 
 /* Assumes that caller fixes checksum csum_diff() and l4_csum_replace() */
-static __always_inline int ipv6_store_daddr(struct __ctx_buff *ctx, __u8 *addr,
-					    int off)
+static __always_inline int
+ipv6_store_daddr(struct __ctx_buff *ctx, const __u8 *addr, int off)
 {
 	return ctx_store_bytes(ctx, off + offsetof(struct ipv6hdr, daddr), addr, 16, 0);
 }

diff --git a/bpf/lib/lb.h b/bpf/lib/lb.h
@@ -652,7 +652,7 @@ lb6_select_backend_id(struct __ctx_buff *ctx __maybe_unused,
 #endif /* LB_SELECTION */
 
 static __always_inline int lb6_xlate(struct __ctx_buff *ctx,
-				     union v6addr *new_dst, __u8 nexthdr,
+				     const union v6addr *new_dst, __u8 nexthdr,
 				     int l3_off, int l4_off,
 				     struct csum_offset *csum_off,
 				     const struct lb6_key *key,

diff --git a/bpf/lib/nat.h b/bpf/lib/nat.h
@@ -920,7 +920,7 @@ snat_v6_can_skip(const struct ipv6_nat_target *target,
 }
 
 static __always_inline __maybe_unused int snat_v6_create_dsr(struct __ctx_buff *ctx,
-							     union v6addr *to_saddr,
+							     const union v6addr *to_saddr,
 							     __be16 to_sport)
 {
 	void *data, *data_end;

diff --git a/bpf/lib/nodeport.h b/bpf/lib/nodeport.h
@@ -179,7 +179,7 @@ static __always_inline bool nodeport_uses_dsr6(const struct ipv6_ct_tuple *tuple
  * then the helper function won't depend the dsr checks.
  */
 static __always_inline bool snat_v6_needed(struct __ctx_buff *ctx,
-					   union v6addr *addr)
+					   const union v6addr *addr)
 {
 	void *data, *data_end;
 	struct ipv6hdr *ip6;
@@ -203,7 +203,7 @@ static __always_inline bool snat_v6_needed(struct __ctx_buff *ctx,
 }
 
 static __always_inline int nodeport_nat_ipv6_fwd(struct __ctx_buff *ctx,
-						 union v6addr *addr)
+						 const union v6addr *addr)
 {
 	struct ipv6_nat_target target = {
 		.min_port = NODEPORT_PORT_MIN_NAT,
@@ -253,7 +253,7 @@ static __always_inline void rss_gen_src6(union v6addr *src,
 
 static __always_inline int dsr_set_ipip6(struct __ctx_buff *ctx,
 					 const struct ipv6hdr *ip6,
-					 union v6addr *backend_addr,
+					 const union v6addr *backend_addr,
 					 __be32 l4_hint, int *ohead)
 {
 	__u16 payload_len = bpf_ntohs(ip6->payload_len) + sizeof(*ip6);
@@ -293,7 +293,7 @@ static __always_inline int dsr_set_ipip6(struct __ctx_buff *ctx,
 #elif DSR_ENCAP_MODE == DSR_ENCAP_NONE
 static __always_inline int dsr_set_ext6(struct __ctx_buff *ctx,
 					struct ipv6hdr *ip6,
-					union v6addr *svc_addr,
+					const union v6addr *svc_addr,
 					__be16 svc_port, int *ohead)
 {
 	struct dsr_opt_v6 opt __align_stack_8 = {};

diff --git a/bpf/lib/trace.h b/bpf/lib/trace.h
@@ -246,8 +246,9 @@ send_trace_notify4(struct __ctx_buff *ctx, enum trace_point obs_point,
 
 static __always_inline void
 send_trace_notify6(struct __ctx_buff *ctx, enum trace_point obs_point,
-		   __u32 src, __u32 dst, union v6addr *orig_addr, __u16 dst_id,
-		   __u32 ifindex, enum trace_reason reason, __u32 monitor)
+		   __u32 src, __u32 dst, const union v6addr *orig_addr,
+		   __u16 dst_id, __u32 ifindex, enum trace_reason reason,
+		   __u32 monitor)
 {
 	__u64 ctx_len = ctx_full_len(ctx);
 	__u64 cap_len = min_t(__u64, monitor ? : TRACE_PAYLOAD_LEN,