diff options
Diffstat (limited to 'ip.c')
| -rw-r--r-- | ip.c | 47 |
1 files changed, 47 insertions, 0 deletions
@@ -13,6 +13,8 @@ */ #include <stddef.h> +#include <netinet/in.h> + #include "util.h" #include "ip.h" @@ -67,3 +69,48 @@ found: *proto = nh; return true; } + +/** + * ipproto_name() - Get IP protocol name from number + * @proto: IP protocol number + * + * Return: pointer to name of protocol @proto + * + * Usually this would be done with getprotobynumber(3) but that reads + * /etc/protocols and might allocate, which isn't possible for us once + * self-isolated. + */ +const char *ipproto_name(uint8_t proto) +{ + switch (proto) { + case IPPROTO_ICMP: + return "ICMP"; + case IPPROTO_TCP: + return "TCP"; + case IPPROTO_UDP: + return "UDP"; + case IPPROTO_ICMPV6: + return "ICMPv6"; + default: + return "<unknown protocol>"; + } +} + +/** + * ip4_class_prefix_len() - Get class based prefix length for IPv4 address + * @addr: IPv4 address + * + * Return: prefix length based on address class, or 32 for other + */ +int ip4_class_prefix_len(const struct in_addr *addr) +{ + in_addr_t a = ntohl(addr->s_addr); + + if (IN_CLASSA(a)) + return 32 - IN_CLASSA_NSHIFT; + if (IN_CLASSB(a)) + return 32 - IN_CLASSB_NSHIFT; + if (IN_CLASSC(a)) + return 32 - IN_CLASSC_NSHIFT; + return 32; +} |