net: explicit cast of IP checksum to 16-bit

GCC 8.1 warned:

In function 'rte_raw_cksum_mbuf':
rte_ip.h:225:22: warning: conversion from 'uint32_t'
{aka 'unsigned int'} to 'uint16_t' {aka 'short unsigned int'}
may change value [-Wconversion]
    tmp = rte_bswap16(tmp);
                      ^~~

In function 'rte_ipv4_cksum':
rte_ip.h:256:35: warning: conversion from 'int' to 'uint16_t'
{aka 'short unsigned int'} may change value [-Wconversion]
  return (cksum == 0xffff) ? cksum : ~cksum;
         ~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~

rte_ip.h:332:9: warning: conversion from 'uint32_t'
{aka 'unsigned int'} to 'uint16_t' {aka 'short unsigned int'}
may change value [-Wconversion]
  return cksum;
         ^~~~~

In function 'rte_ipv6_udptcp_cksum':
rte_ip.h:421:9: warning: conversion from 'uint32_t' {aka 'unsigned int'}
to 'uint16_t' {aka 'short unsigned int'} may change value [-Wconversion]
  return cksum;
         ^~~~~

Fixes: 6006818cfb26 ("net: new checksum functions")
Fixes: 4199fdea60c3 ("mbuf: generic support for TCP segmentation offload")
Cc: stable@dpdk.org
Signed-off-by: Andy Green <andy@warmcat.com>

diff --git a/lib/librte_net/rte_ip.h b/lib/librte_net/rte_ip.h
index f32684c..edbe433 100644 (file)
--- a/lib/librte_net/rte_ip.h
+++ b/lib/librte_net/rte_ip.h
@@ -222,7 +222,7 @@ rte_raw_cksum_mbuf(const struct rte_mbuf *m, uint32_t off, uint32_t len,
        for (;;) {
                tmp = __rte_raw_cksum(buf, seglen, 0);
                if (done & 1)
-                       tmp = rte_bswap16(tmp);
+                       tmp = rte_bswap16((uint16_t)tmp);
                sum += tmp;
                done += seglen;
                if (done == len)
@@ -253,7 +253,7 @@ rte_ipv4_cksum(const struct ipv4_hdr *ipv4_hdr)
 {
        uint16_t cksum;
        cksum = rte_raw_cksum(ipv4_hdr, sizeof(struct ipv4_hdr));
-       return (cksum == 0xffff) ? cksum : ~cksum;
+       return (cksum == 0xffff) ? cksum : (uint16_t)~cksum;
 }
 
 /**
@@ -329,7 +329,7 @@ rte_ipv4_udptcp_cksum(const struct ipv4_hdr *ipv4_hdr, const void *l4_hdr)
        if (cksum == 0)
                cksum = 0xffff;
 
-       return cksum;
+       return (uint16_t)cksum;
 }
 
 /**
@@ -418,7 +418,7 @@ rte_ipv6_udptcp_cksum(const struct ipv6_hdr *ipv6_hdr, const void *l4_hdr)
        if (cksum == 0)
                cksum = 0xffff;
 
-       return cksum;
+       return (uint16_t)cksum;
 }
 
 #ifdef __cplusplus