diff options
Diffstat (limited to 'libnetutils/ifc_utils.c')
| -rw-r--r-- | libnetutils/ifc_utils.c | 355 |
1 files changed, 344 insertions, 11 deletions
diff --git a/libnetutils/ifc_utils.c b/libnetutils/ifc_utils.c index c9d6ed2..0a2f760 100644 --- a/libnetutils/ifc_utils.c +++ b/libnetutils/ifc_utils.c @@ -26,15 +26,18 @@ #include <netinet/in.h> #include <arpa/inet.h> #include <net/if.h> +#include <netdb.h> #include <linux/if.h> #include <linux/if_ether.h> #include <linux/if_arp.h> -#include <linux/sockios.h> +#include <linux/netlink.h> #include <linux/route.h> #include <linux/ipv6_route.h> -#include <netdb.h> -#include <linux/wireless.h> +#include <linux/rtnetlink.h> +#include <linux/sockios.h> + +#include "netutils/ifc.h" #ifdef ANDROID #define LOG_TAG "NetUtils" @@ -51,6 +54,10 @@ static int ifc_ctl_sock = -1; static int ifc_ctl_sock6 = -1; void printerr(char *fmt, ...); +#define DBG 0 +#define INET_ADDRLEN 4 +#define INET6_ADDRLEN 16 + in_addr_t prefixLengthToIpv4Netmask(int prefix_length) { in_addr_t mask = 0; @@ -86,15 +93,41 @@ static const char *ipaddr_to_string(in_addr_t addr) return inet_ntoa(in_addr); } +int string_to_ip(const char *string, struct sockaddr_storage *ss) { + struct addrinfo hints, *ai; + int ret; + + if (ss == NULL) { + return -EFAULT; + } + + memset(&hints, 0, sizeof(hints)); + hints.ai_family = AF_UNSPEC; + hints.ai_flags = AI_NUMERICHOST; + hints.ai_socktype = SOCK_DGRAM; + + ret = getaddrinfo(string, NULL, &hints, &ai); + if (ret == 0) { + memcpy(ss, ai->ai_addr, ai->ai_addrlen); + freeaddrinfo(ai); + } + + return ret; +} + int ifc_init(void) { + int ret; if (ifc_ctl_sock == -1) { - ifc_ctl_sock = socket(AF_INET, SOCK_DGRAM, 0); + ifc_ctl_sock = socket(AF_INET, SOCK_DGRAM, 0); if (ifc_ctl_sock < 0) { printerr("socket() failed: %s\n", strerror(errno)); } } - return ifc_ctl_sock < 0 ? -1 : 0; + + ret = ifc_ctl_sock < 0 ? -1 : 0; + if (DBG) printerr("ifc_init_returning %d", ret); + return ret; } int ifc_init6(void) @@ -110,6 +143,7 @@ int ifc_init6(void) void ifc_close(void) { + if (DBG) printerr("ifc_close"); if (ifc_ctl_sock != -1) { (void)close(ifc_ctl_sock); ifc_ctl_sock = -1; @@ -141,7 +175,7 @@ int ifc_get_hwaddr(const char *name, void *ptr) if(r < 0) return -1; memcpy(ptr, &ifr.ifr_hwaddr.sa_data, ETH_ALEN); - return 0; + return 0; } int ifc_get_ifindex(const char *name, int *if_indexp) @@ -169,12 +203,16 @@ static int ifc_set_flags(const char *name, unsigned set, unsigned clr) int ifc_up(const char *name) { - return ifc_set_flags(name, IFF_UP, 0); + int ret = ifc_set_flags(name, IFF_UP, 0); + if (DBG) printerr("ifc_up(%s) = %d", name, ret); + return ret; } int ifc_down(const char *name) { - return ifc_set_flags(name, 0, IFF_UP); + int ret = ifc_set_flags(name, 0, IFF_UP); + if (DBG) printerr("ifc_down(%s) = %d", name, ret); + return ret; } static void init_sockaddr_in(struct sockaddr *sa, in_addr_t addr) @@ -188,11 +226,193 @@ static void init_sockaddr_in(struct sockaddr *sa, in_addr_t addr) int ifc_set_addr(const char *name, in_addr_t addr) { struct ifreq ifr; + int ret; ifc_init_ifr(name, &ifr); init_sockaddr_in(&ifr.ifr_addr, addr); - return ioctl(ifc_ctl_sock, SIOCSIFADDR, &ifr); + ret = ioctl(ifc_ctl_sock, SIOCSIFADDR, &ifr); + if (DBG) printerr("ifc_set_addr(%s, xx) = %d", name, ret); + return ret; +} + +/* + * Adds or deletes an IP address on an interface. + * + * Action is one of: + * - RTM_NEWADDR (to add a new address) + * - RTM_DELADDR (to delete an existing address) + * + * Returns zero on success and negative errno on failure. + */ +int ifc_act_on_address(int action, const char *name, const char *address, + int prefixlen) { + int ifindex, s, len, ret; + struct sockaddr_storage ss; + void *addr; + size_t addrlen; + struct { + struct nlmsghdr n; + struct ifaddrmsg r; + // Allow for IPv6 address, headers, and padding. + char attrbuf[NLMSG_ALIGN(sizeof(struct nlmsghdr)) + + NLMSG_ALIGN(sizeof(struct rtattr)) + + NLMSG_ALIGN(INET6_ADDRLEN)]; + } req; + struct rtattr *rta; + struct nlmsghdr *nh; + struct nlmsgerr *err; + char buf[NLMSG_ALIGN(sizeof(struct nlmsghdr)) + + NLMSG_ALIGN(sizeof(struct nlmsgerr)) + + NLMSG_ALIGN(sizeof(struct nlmsghdr))]; + + // Get interface ID. + ifindex = if_nametoindex(name); + if (ifindex == 0) { + return -errno; + } + + // Convert string representation to sockaddr_storage. + ret = string_to_ip(address, &ss); + if (ret) { + return ret; + } + + // Determine address type and length. + if (ss.ss_family == AF_INET) { + struct sockaddr_in *sin = (struct sockaddr_in *) &ss; + addr = &sin->sin_addr; + addrlen = INET_ADDRLEN; + } else if (ss.ss_family == AF_INET6) { + struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *) &ss; + addr = &sin6->sin6_addr; + addrlen = INET6_ADDRLEN; + } else { + return -EAFNOSUPPORT; + } + + // Fill in netlink structures. + memset(&req, 0, sizeof(req)); + + // Netlink message header. + req.n.nlmsg_len = NLMSG_LENGTH(sizeof(req.r)); + req.n.nlmsg_type = action; + req.n.nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK; + req.n.nlmsg_pid = getpid(); + + // Interface address message header. + req.r.ifa_family = ss.ss_family; + req.r.ifa_prefixlen = prefixlen; + req.r.ifa_index = ifindex; + + // Routing attribute. Contains the actual IP address. + rta = (struct rtattr *) (((char *) &req) + NLMSG_ALIGN(req.n.nlmsg_len)); + rta->rta_type = IFA_LOCAL; + rta->rta_len = RTA_LENGTH(addrlen); + req.n.nlmsg_len = NLMSG_ALIGN(req.n.nlmsg_len) + RTA_LENGTH(addrlen); + memcpy(RTA_DATA(rta), addr, addrlen); + + s = socket(PF_NETLINK, SOCK_RAW, NETLINK_ROUTE); + if (send(s, &req, req.n.nlmsg_len, 0) < 0) { + close(s); + return -errno; + } + + len = recv(s, buf, sizeof(buf), 0); + close(s); + if (len < 0) { + return -errno; + } + + // Parse the acknowledgement to find the return code. + nh = (struct nlmsghdr *) buf; + if (!NLMSG_OK(nh, (unsigned) len) || nh->nlmsg_type != NLMSG_ERROR) { + return -EINVAL; + } + err = NLMSG_DATA(nh); + + // Return code is negative errno. + return err->error; +} + +int ifc_add_address(const char *name, const char *address, int prefixlen) { + return ifc_act_on_address(RTM_NEWADDR, name, address, prefixlen); +} + +int ifc_del_address(const char *name, const char * address, int prefixlen) { + return ifc_act_on_address(RTM_DELADDR, name, address, prefixlen); +} + +/* + * Clears IPv6 addresses on the specified interface. + */ +int ifc_clear_ipv6_addresses(const char *name) { + char rawaddrstr[INET6_ADDRSTRLEN], addrstr[INET6_ADDRSTRLEN]; + unsigned int prefixlen; + int lasterror = 0, i, j, ret; + char ifname[64]; // Currently, IFNAMSIZ = 16. + FILE *f = fopen("/proc/net/if_inet6", "r"); + if (!f) { + return -errno; + } + + // Format: + // 20010db8000a0001fc446aa4b5b347ed 03 40 00 01 wlan0 + while (fscanf(f, "%32s %*02x %02x %*02x %*02x %63s\n", + rawaddrstr, &prefixlen, ifname) == 3) { + // Is this the interface we're looking for? + if (strcmp(name, ifname)) { + continue; + } + + // Put the colons back into the address. + for (i = 0, j = 0; i < 32; i++, j++) { + addrstr[j] = rawaddrstr[i]; + if (i % 4 == 3) { + addrstr[++j] = ':'; + } + } + addrstr[j - 1] = '\0'; + + // Don't delete the link-local address as well, or it will disable IPv6 + // on the interface. + if (strncmp(addrstr, "fe80:", 5) == 0) { + continue; + } + + ret = ifc_del_address(ifname, addrstr, prefixlen); + if (ret) { + LOGE("Deleting address %s/%d on %s: %s", addrstr, prefixlen, ifname, + strerror(-ret)); + lasterror = ret; + } + } + + fclose(f); + return lasterror; +} + +/* + * Clears IPv4 addresses on the specified interface. + */ +void ifc_clear_ipv4_addresses(const char *name) { + unsigned count, addr; + ifc_init(); + for (count=0, addr=1;((addr != 0) && (count < 255)); count++) { + if (ifc_get_addr(name, &addr) < 0) + break; + if (addr) + ifc_set_addr(name, 0); + } + ifc_close(); +} + +/* + * Clears all IP addresses on the specified interface. + */ +int ifc_clear_addresses(const char *name) { + ifc_clear_ipv4_addresses(name); + return ifc_clear_ipv6_addresses(name); } int ifc_set_hwaddr(const char *name, const void *ptr) @@ -206,6 +426,19 @@ int ifc_set_hwaddr(const char *name, const void *ptr) return ioctl(ifc_ctl_sock, SIOCSIFHWADDR, &ifr); } +int ifc_set_mask(const char *name, in_addr_t mask) +{ + struct ifreq ifr; + int ret; + + ifc_init_ifr(name, &ifr); + init_sockaddr_in(&ifr.ifr_addr, mask); + + ret = ioctl(ifc_ctl_sock, SIOCSIFNETMASK, &ifr); + if (DBG) printerr("ifc_set_mask(%s, xx) = %d", name, ret); + return ret; +} + int ifc_set_prefixLength(const char *name, int prefixLength) { struct ifreq ifr; @@ -313,6 +546,7 @@ int ifc_act_on_ipv4_route(int action, const char *ifname, struct in_addr dst, in return result; } +/* deprecated - v4 only */ int ifc_create_default_route(const char *name, in_addr_t gw) { struct in_addr in_dst, in_gw; @@ -320,7 +554,20 @@ int ifc_create_default_route(const char *name, in_addr_t gw) in_dst.s_addr = 0; in_gw.s_addr = gw; - return ifc_act_on_route(SIOCADDRT, name, in_dst, 0, in_gw); + int ret = ifc_act_on_ipv4_route(SIOCADDRT, name, in_dst, 0, in_gw); + if (DBG) printerr("ifc_create_default_route(%s, %d) = %d", name, gw, ret); + return ret; +} + +/* deprecated v4-only */ +int ifc_add_host_route(const char *name, in_addr_t dst) +{ + struct in_addr in_dst, in_gw; + + in_dst.s_addr = dst; + in_gw.s_addr = 0; + + return ifc_act_on_ipv4_route(SIOCADDRT, name, in_dst, 32, in_gw); } int ifc_enable(const char *ifname) @@ -449,6 +696,70 @@ int ifc_remove_host_routes(const char *name) } /* + * Return the address of the default gateway + * + * TODO: factor out common code from this and remove_host_routes() + * so that we only scan /proc/net/route in one place. + * + * DEPRECATED + */ +int ifc_get_default_route(const char *ifname) +{ + char name[64]; + in_addr_t dest, gway, mask; + int flags, refcnt, use, metric, mtu, win, irtt; + int result; + FILE *fp; + + fp = fopen("/proc/net/route", "r"); + if (fp == NULL) + return 0; + /* Skip the header line */ + if (fscanf(fp, "%*[^\n]\n") < 0) { + fclose(fp); + return 0; + } + ifc_init(); + result = 0; + for (;;) { + int nread = fscanf(fp, "%63s%X%X%X%d%d%d%X%d%d%d\n", + name, &dest, &gway, &flags, &refcnt, &use, &metric, &mask, + &mtu, &win, &irtt); + if (nread != 11) { + break; + } + if ((flags & (RTF_UP|RTF_GATEWAY)) == (RTF_UP|RTF_GATEWAY) + && dest == 0 + && strcmp(ifname, name) == 0) { + result = gway; + break; + } + } + fclose(fp); + ifc_close(); + return result; +} + +/* + * Sets the specified gateway as the default route for the named interface. + * DEPRECATED + */ +int ifc_set_default_route(const char *ifname, in_addr_t gateway) +{ + struct in_addr addr; + int result; + + ifc_init(); + addr.s_addr = gateway; + if ((result = ifc_create_default_route(ifname, gateway)) < 0) { + LOGD("failed to add %s as default route for %s: %s", + inet_ntoa(addr), ifname, strerror(errno)); + } + ifc_close(); + return result; +} + +/* * Removes the default route for the named interface. */ int ifc_remove_default_route(const char *ifname) @@ -627,9 +938,31 @@ int ifc_act_on_route(int action, const char *ifname, const char *dst, int prefix return ret; } +/* + * DEPRECATED + */ +int ifc_add_ipv4_route(const char *ifname, struct in_addr dst, int prefix_length, + struct in_addr gw) +{ + int i =ifc_act_on_ipv4_route(SIOCADDRT, ifname, dst, prefix_length, gw); + if (DBG) printerr("ifc_add_ipv4_route(%s, xx, %d, xx) = %d", ifname, prefix_length, i); + return i; +} + +/* + * DEPRECATED + */ +int ifc_add_ipv6_route(const char *ifname, struct in6_addr dst, int prefix_length, + struct in6_addr gw) +{ + return ifc_act_on_ipv6_route(SIOCADDRT, ifname, dst, prefix_length, gw); +} + int ifc_add_route(const char *ifname, const char *dst, int prefix_length, const char *gw) { - return ifc_act_on_route(SIOCADDRT, ifname, dst, prefix_length, gw); + int i = ifc_act_on_route(SIOCADDRT, ifname, dst, prefix_length, gw); + if (DBG) printerr("ifc_add_route(%s, %s, %d, %s) = %d", ifname, dst, prefix_length, gw, i); + return i; } int ifc_remove_route(const char *ifname, const char*dst, int prefix_length, const char *gw) |