[ovs-dev] [PATCH 03/14] packets: Add new functions for IPv4 and IPv6 address parsing.

Justin Pettit jpettit at ovn.org
Thu Dec 10 00:05:46 UTC 2015


Acked-by: Justin Pettit <jpettit at ovn.org>

--Justin


> On Dec 8, 2015, at 5:08 PM, Ben Pfaff <blp at ovn.org> wrote:
> 
> These will be used in an upcoming patch to reduce duplicated code.
> 
> Signed-off-by: Ben Pfaff <blp at ovn.org>
> ---
> lib/packets.c | 132 ++++++++++++++++++++++++++++++++++++++++++----------------
> lib/packets.h |   7 ++++
> 2 files changed, 102 insertions(+), 37 deletions(-)
> 
> diff --git a/lib/packets.c b/lib/packets.c
> index 0ad5073..309ec0c 100644
> --- a/lib/packets.c
> +++ b/lib/packets.c
> @@ -416,6 +416,14 @@ ip_format_masked(ovs_be32 ip, ovs_be32 mask, struct ds *s)
>     }
> }
> 
> +/* Parses string 's', which must be an IP address.  Stores the IP address into
> + * '*ip'.  Returns true if successful, otherwise false. */
> +bool
> +ip_parse(const char *s, ovs_be32 *ip)
> +{
> +    return inet_pton(AF_INET, s, ip) == 1;
> +}
> +
> /* Parses string 's', which must be an IP address with an optional netmask or
>  * CIDR prefix length.  Stores the IP address into '*ip' and the netmask into
>  * '*mask'.  (If 's' does not contain a netmask, 255.255.255.255 is
> @@ -447,6 +455,93 @@ ip_parse_masked(const char *s, ovs_be32 *ip, ovs_be32 *mask)
>     return NULL;
> }
> 
> +/* Similar to ip_parse_masked(), but the mask, if present, must be a CIDR mask
> + * and is returned as a prefix length in '*plen'. */
> +char * OVS_WARN_UNUSED_RESULT
> +ip_parse_cidr(const char *s, ovs_be32 *ip, unsigned int *plen)
> +{
> +    ovs_be32 mask;
> +    char *error;
> +
> +    error = ip_parse_masked(s, ip, &mask);
> +    if (error) {
> +        return error;
> +    }
> +
> +    if (!ip_is_cidr(mask)) {
> +        return xasprintf("%s: CIDR network required", s);
> +    }
> +    *plen = ip_count_cidr_bits(mask);
> +    return NULL;
> +}
> +
> +/* Parses string 's', which must be an IPv6 address.  Stores the IPv6 address
> + * into '*ip'.  Returns true if successful, otherwise false. */
> +bool
> +ipv6_parse(const char *s, struct in6_addr *ip)
> +{
> +    return inet_pton(AF_INET6, s, ip) == 1;
> +}
> +
> +/* Parses string 's', which must be an IPv6 address with an optional netmask or
> + * CIDR prefix length.  Stores the IPv6 address into '*ip' and the netmask into
> + * '*mask'.  (If 's' does not contain a netmask, all-one-bits is assumed.)
> + *
> + * Returns NULL if successful, otherwise an error message that the caller must
> + * free(). */
> +char * OVS_WARN_UNUSED_RESULT
> +ipv6_parse_masked(const char *s, struct in6_addr *ip, struct in6_addr *mask)
> +{
> +    char ipv6_s[IPV6_SCAN_LEN + 1];
> +    int prefix;
> +    int n;
> +
> +    if (ovs_scan(s, IPV6_SCAN_FMT"%n", ipv6_s, &n) && ipv6_parse(ipv6_s, ip)) {
> +        s += n;
> +        if (!*s) {
> +            *mask = in6addr_exact;
> +        } else if (ovs_scan(s, "/%d%n", &prefix, &n) && !s[n]) {
> +            if (prefix <= 0 || prefix > 128) {
> +                return xasprintf("%s: IPv6 network prefix bits not between 0 "
> +                                 "and 128", s);
> +            }
> +            *mask = ipv6_create_mask(prefix);
> +        } else if (ovs_scan(s, "/"IPV6_SCAN_FMT"%n", ipv6_s, &n)
> +                   && !s[n]
> +                   && ipv6_parse(ipv6_s, mask)) {
> +            /* OK. */
> +        } else {
> +            return xasprintf("%s: syntax error expecting IPv6 prefix length "
> +                             "or mask", s);
> +        }
> +        return NULL;
> +    }
> +    return xasprintf("%s: invalid IPv6 address", s);
> +}
> +
> +/* Similar to ipv6_parse_masked(), but the mask, if present, must be a CIDR
> + * mask and is returned as a prefix length in '*plen'. */
> +char * OVS_WARN_UNUSED_RESULT
> +ipv6_parse_cidr(const char *s, struct in6_addr *ip, unsigned int *plen)
> +{
> +    struct in6_addr mask;
> +    char *error;
> +
> +    error = ipv6_parse_masked(s, ip, &mask);
> +    if (error) {
> +        return error;
> +    }
> +
> +    if (!ipv6_is_cidr(&mask)) {
> +        return xasprintf("%s: IPv6 CIDR network required", s);
> +    }
> +    *plen = ipv6_count_cidr_bits(&mask);
> +    return NULL;
> +}
> +
> +/* Stores the string representation of the IPv6 address 'addr' into the
> + * character array 'addr_str', which must be at least INET6_ADDRSTRLEN
> + * bytes long. */
> void
> ipv6_format_addr(const struct in6_addr *addr, struct ds *s)
> {
> @@ -612,43 +707,6 @@ ipv6_is_cidr(const struct in6_addr *netmask)
>     return true;
> }
> 
> -/* Parses string 's', which must be an IPv6 address with an optional
> - * CIDR prefix length.  Stores the IP address into '*ipv6' and the CIDR
> - * prefix in '*prefix'.  (If 's' does not contain a CIDR length, all-ones
> - * is assumed.)
> - *
> - * Returns NULL if successful, otherwise an error message that the caller must
> - * free(). */
> -char * OVS_WARN_UNUSED_RESULT
> -ipv6_parse_masked(const char *s, struct in6_addr *ipv6, struct in6_addr *mask)
> -{
> -    char ipv6_s[IPV6_SCAN_LEN + 1];
> -    char mask_s[IPV6_SCAN_LEN + 1];
> -    int prefix;
> -    int n;
> -
> -    if (ovs_scan(s, IPV6_SCAN_FMT"/"IPV6_SCAN_FMT"%n", ipv6_s, mask_s, &n)
> -        && inet_pton(AF_INET6, ipv6_s, ipv6) == 1
> -        && inet_pton(AF_INET6, mask_s, mask) == 1
> -        && !s[n]) {
> -        /* OK. */
> -    } else if (ovs_scan(s, IPV6_SCAN_FMT"/%d%n", ipv6_s, &prefix, &n)
> -        && inet_pton(AF_INET6, ipv6_s, ipv6) == 1
> -        && !s[n]) {
> -        if (prefix <= 0 || prefix > 128) {
> -            return xasprintf("%s: prefix bits not between 0 and 128", s);
> -        }
> -        *mask = ipv6_create_mask(prefix);
> -    } else if (ovs_scan(s, IPV6_SCAN_FMT"%n", ipv6_s, &n)
> -               && inet_pton(AF_INET6, ipv6_s, ipv6) == 1
> -               && !s[n]) {
> -        *mask = in6addr_exact;
> -    } else {
> -        return xasprintf("%s: invalid IP address", s);
> -    }
> -    return NULL;
> -}
> -
> /* Populates 'b' with an Ethernet II packet headed with the given 'eth_dst',
>  * 'eth_src' and 'eth_type' parameters.  A payload of 'size' bytes is allocated
>  * in 'b' and returned.  This payload may be populated with appropriate
> diff --git a/lib/packets.h b/lib/packets.h
> index 1e0417a..eaa329f 100644
> --- a/lib/packets.h
> +++ b/lib/packets.h
> @@ -581,8 +581,11 @@ ip_is_local_multicast(ovs_be32 ip)
> }
> int ip_count_cidr_bits(ovs_be32 netmask);
> void ip_format_masked(ovs_be32 ip, ovs_be32 mask, struct ds *);
> +bool ip_parse(const char *s, ovs_be32 *ip);
> char *ip_parse_masked(const char *s, ovs_be32 *ip, ovs_be32 *mask)
>     OVS_WARN_UNUSED_RESULT;
> +char *ip_parse_cidr(const char *s, ovs_be32 *ip, unsigned int *plen)
> +    OVS_WARN_UNUSED_RESULT;
> 
> #define IP_VER(ip_ihl_ver) ((ip_ihl_ver) >> 4)
> #define IP_IHL(ip_ihl_ver) ((ip_ihl_ver) & 15)
> @@ -1011,8 +1014,12 @@ struct in6_addr ipv6_addr_bitand(const struct in6_addr *src,
> struct in6_addr ipv6_create_mask(int mask);
> int ipv6_count_cidr_bits(const struct in6_addr *netmask);
> bool ipv6_is_cidr(const struct in6_addr *netmask);
> +
> +bool ipv6_parse(const char *s, struct in6_addr *ip);
> char *ipv6_parse_masked(const char *s, struct in6_addr *ipv6,
>                         struct in6_addr *mask);
> +char *ipv6_parse_cidr(const char *s, struct in6_addr *ip, unsigned int *plen)
> +    OVS_WARN_UNUSED_RESULT;
> 
> void *eth_compose(struct dp_packet *, const struct eth_addr eth_dst,
>                   const struct eth_addr eth_src, uint16_t eth_type,
> -- 
> 2.1.3
> 
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