2 $Id: socket.c,v 1.6 2010-01-05 19:05:52 franklahm Exp $
3 Copyright (c) 2009 Frank Lahm <franklahm@gmail.com>
5 This program is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 2 of the License, or
8 (at your option) any later version.
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
18 * Netatalk utility functions
23 #endif /* HAVE_CONFIG_H */
27 #include <sys/types.h>
28 #include <sys/socket.h>
29 #include <arpa/inet.h>
30 #include <netinet/in.h>
34 static char ipv4mapprefix[] = {0,0,0,0,0,0,0,0,0,0,0xff,0xff};
37 * @brief set or unset non-blocking IO on a fd
39 * @param fd (r) File descriptor
40 * @param cmd (r) 0: disable non-blocking IO, ie block\n
41 * <>0: enable non-blocking IO
43 * @returns 0 on success, -1 on failure
45 int setnonblock(int fd, int cmd)
50 if ((fdflags = ofdflags = fcntl(fd, F_GETFL, 0)) == -1)
54 fdflags |= O_NONBLOCK;
56 fdflags &= ~O_NONBLOCK;
58 if (fdflags != ofdflags)
59 if (fcntl(fd, F_SETFL, fdflags) == -1)
66 * @brief convert an IPv4 or IPv6 address to a static string using inet_ntop
68 * IPv6 mapped IPv4 addresses are returned as IPv4 addreses eg
69 * ::ffff:10.0.0.0 is returned as "10.0.0.0".
71 * @param sa (r) pointer to an struct sockaddr
73 * @returns pointer to a static string cotaining the converted address as string.\n
74 * On error pointers to "0.0.0.0" or "::0" are returned.
76 const char *getip_string(const struct sockaddr *sa)
78 static char ip4[INET_ADDRSTRLEN];
79 static char ip6[INET6_ADDRSTRLEN];
81 switch (sa->sa_family) {
84 const struct sockaddr_in *sai4 = (const struct sockaddr_in *)sa;
85 if ((inet_ntop(AF_INET, &(sai4->sin_addr), ip4, INET_ADDRSTRLEN)) == NULL)
90 const struct sockaddr_in6 *sai6 = (const struct sockaddr_in6 *)sa;
91 if ((inet_ntop(AF_INET6, &(sai6->sin6_addr), ip6, INET6_ADDRSTRLEN)) == NULL)
94 /* Deal with IPv6 mapped IPv4 addresses*/
95 if ((memcmp(sai6->sin6_addr.s6_addr, ipv4mapprefix, sizeof(ipv4mapprefix))) == 0)
96 return (strrchr(ip6, ':') + 1);
100 return "getip_string ERROR";
103 /* We never get here */
107 * @brief return port number from struct sockaddr
109 * @param sa (r) pointer to an struct sockaddr
111 * @returns port as unsigned int
113 unsigned int getip_port(const struct sockaddr *sa)
115 if (sa->sa_family == AF_INET) { /* IPv4 */
116 const struct sockaddr_in *sai4 = (const struct sockaddr_in *)sa;
117 return ntohs(sai4->sin_port);
119 const struct sockaddr_in6 *sai6 = (const struct sockaddr_in6 *)sa;
120 return ntohs(sai6->sin6_port);
123 /* We never get here */
127 * @brief apply netmask to IP (v4 or v6)
129 * Modifies IP address in sa->sin[6]_addr-s[6]_addr. The caller is responsible
130 * for passing a value for mask that is sensible to the passed address,
131 * eg 0 <= mask <= 32 for IPv4 or 0<= mask <= 128 for IPv6. mask > 32 for
132 * IPv4 is treated as mask = 32, mask > 128 is set to 128 for IPv6.
134 * @param ai (rw) pointer to an struct sockaddr
135 * @parma mask (r) number of maskbits
137 void apply_ip_mask(struct sockaddr *sa, uint32_t mask)
140 switch (sa->sa_family) {
145 struct sockaddr_in *si = (struct sockaddr_in *)sa;
146 uint32_t nmask = mask ? ~((1 << (32 - mask)) - 1) : 0;
147 si->sin_addr.s_addr &= htonl(nmask);
154 int i, maskbytes, maskbits;
155 struct sockaddr_in6 *si6 = (struct sockaddr_in6 *)sa;
157 /* Deal with IPv6 mapped IPv4 addresses*/
158 if ((memcmp(si6->sin6_addr.s6_addr, ipv4mapprefix, sizeof(ipv4mapprefix))) == 0) {
164 maskbytes = (128 - mask) / 8; /* maskbytes really are those that will be 0'ed */
167 for (i = maskbytes - 1; i >= 0; i--)
168 si6->sin6_addr.s6_addr[15 - i] = 0;
170 si6->sin6_addr.s6_addr[15 - maskbytes] &= ~((1 << (8 - maskbits)) - 1);
179 * @brief compare IP addresses for equality
181 * @param sa1 (r) pointer to an struct sockaddr
182 * @param sa2 (r) pointer to an struct sockaddr
184 * @returns Addresses are converted to strings and compared with strcmp and
185 * the result of strcmp is returned.
187 * @note IPv6 mapped IPv4 addresses are treated as IPv4 addresses.
189 int compare_ip(const struct sockaddr *sa1, const struct sockaddr *sa2)
195 ip1 = strdup(getip_string(sa1));
196 ip2 = getip_string(sa2);
198 ret = strcmp(ip1, ip2);