diff options
Diffstat (limited to 'src/compat/checksum/checksum_partial_compat.h')
| -rw-r--r-- | src/compat/checksum/checksum_partial_compat.h | 201 |
1 files changed, 201 insertions, 0 deletions
diff --git a/src/compat/checksum/checksum_partial_compat.h b/src/compat/checksum/checksum_partial_compat.h new file mode 100644 index 0000000..5175d84 --- /dev/null +++ b/src/compat/checksum/checksum_partial_compat.h @@ -0,0 +1,201 @@ +#include <net/route.h> +#include <net/esp.h> +#include <net/ip.h> +#include <net/ipv6.h> +#define IP6_MF 0x0001 +#define IP6_OFFSET 0xFFF8 +static inline int skb_maybe_pull_tail(struct sk_buff *skb, unsigned int len, unsigned int max) +{ + if (skb_headlen(skb) >= len) + return 0; + if (max > skb->len) + max = skb->len; + if (__pskb_pull_tail(skb, max - skb_headlen(skb)) == NULL) + return -ENOMEM; + if (skb_headlen(skb) < len) + return -EPROTO; + return 0; +} +#define MAX_IP_HDR_LEN 128 +static inline int skb_checksum_setup_ip(struct sk_buff *skb, bool recalculate) +{ + unsigned int off; + bool fragment; + int err; + fragment = false; + err = skb_maybe_pull_tail(skb, sizeof(struct iphdr), MAX_IP_HDR_LEN); + if (err < 0) + goto out; + if (ip_hdr(skb)->frag_off & htons(IP_OFFSET | IP_MF)) + fragment = true; + off = ip_hdrlen(skb); + err = -EPROTO; + if (fragment) + goto out; + switch (ip_hdr(skb)->protocol) { + case IPPROTO_TCP: + err = skb_maybe_pull_tail(skb, + off + sizeof(struct tcphdr), + MAX_IP_HDR_LEN); + if (err < 0) + goto out; + + if (!skb_partial_csum_set(skb, off, + offsetof(struct tcphdr, check))) { + err = -EPROTO; + goto out; + } + + if (recalculate) + tcp_hdr(skb)->check = + ~csum_tcpudp_magic(ip_hdr(skb)->saddr, + ip_hdr(skb)->daddr, + skb->len - off, + IPPROTO_TCP, 0); + break; + case IPPROTO_UDP: + err = skb_maybe_pull_tail(skb, + off + sizeof(struct udphdr), + MAX_IP_HDR_LEN); + if (err < 0) + goto out; + + if (!skb_partial_csum_set(skb, off, + offsetof(struct udphdr, check))) { + err = -EPROTO; + goto out; + } + + if (recalculate) + udp_hdr(skb)->check = + ~csum_tcpudp_magic(ip_hdr(skb)->saddr, + ip_hdr(skb)->daddr, + skb->len - off, + IPPROTO_UDP, 0); + break; + default: + goto out; + } + err = 0; +out: + return err; +} +#define MAX_IPV6_HDR_LEN 256 +#define OPT_HDR(type, skb, off) \ + (type *)(skb_network_header(skb) + (off)) +static inline int skb_checksum_setup_ipv6(struct sk_buff *skb, bool recalculate) +{ + int err; + u8 nexthdr; + unsigned int off; + unsigned int len; + bool fragment; + bool done; + fragment = false; + done = false; + off = sizeof(struct ipv6hdr); + err = skb_maybe_pull_tail(skb, off, MAX_IPV6_HDR_LEN); + if (err < 0) + goto out; + nexthdr = ipv6_hdr(skb)->nexthdr; + len = sizeof(struct ipv6hdr) + ntohs(ipv6_hdr(skb)->payload_len); + while (off <= len && !done) { + switch (nexthdr) { + case IPPROTO_DSTOPTS: + case IPPROTO_HOPOPTS: + case IPPROTO_ROUTING: { + struct ipv6_opt_hdr *hp; + + err = skb_maybe_pull_tail(skb, off + sizeof(struct ipv6_opt_hdr), MAX_IPV6_HDR_LEN); + if (err < 0) + goto out; + hp = OPT_HDR(struct ipv6_opt_hdr, skb, off); + nexthdr = hp->nexthdr; + off += ipv6_optlen(hp); + break; + } + case IPPROTO_FRAGMENT: { + struct frag_hdr *hp; + err = skb_maybe_pull_tail(skb, off + sizeof(struct frag_hdr), MAX_IPV6_HDR_LEN); + if (err < 0) + goto out; + hp = OPT_HDR(struct frag_hdr, skb, off); + if (hp->frag_off & htons(IP6_OFFSET | IP6_MF)) + fragment = true; + nexthdr = hp->nexthdr; + off += sizeof(struct frag_hdr); + break; + } + default: + done = true; + break; + } + } + err = -EPROTO; + if (!done || fragment) + goto out; + switch (nexthdr) { + case IPPROTO_TCP: + err = skb_maybe_pull_tail(skb, + off + sizeof(struct tcphdr), + MAX_IPV6_HDR_LEN); + if (err < 0) + goto out; + + if (!skb_partial_csum_set(skb, off, + offsetof(struct tcphdr, check))) { + err = -EPROTO; + goto out; + } + + if (recalculate) + tcp_hdr(skb)->check = + ~csum_ipv6_magic(&ipv6_hdr(skb)->saddr, + &ipv6_hdr(skb)->daddr, + skb->len - off, + IPPROTO_TCP, 0); + break; + case IPPROTO_UDP: + err = skb_maybe_pull_tail(skb, + off + sizeof(struct udphdr), + MAX_IPV6_HDR_LEN); + if (err < 0) + goto out; + + if (!skb_partial_csum_set(skb, off, + offsetof(struct udphdr, check))) { + err = -EPROTO; + goto out; + } + + if (recalculate) + udp_hdr(skb)->check = + ~csum_ipv6_magic(&ipv6_hdr(skb)->saddr, + &ipv6_hdr(skb)->daddr, + skb->len - off, + IPPROTO_UDP, 0); + break; + default: + goto out; + } + err = 0; +out: + return err; +} +static inline int skb_checksum_setup(struct sk_buff *skb, bool recalculate) +{ + int err; + switch (skb->protocol) { + case htons(ETH_P_IP): + err = skb_checksum_setup_ip(skb, recalculate); + break; + + case htons(ETH_P_IPV6): + err = skb_checksum_setup_ipv6(skb, recalculate); + break; + default: + err = -EPROTO; + break; + } + return err; +} |