From 09dd819d2794caf1a17cd03592c100755fb25577 Mon Sep 17 00:00:00 2001 From: Robert Greenwalt Date: Tue, 1 Feb 2011 15:21:21 -0800 Subject: [PATCH] Stop using netmask in the framework This pushes prefixLength down as far as we can. bug:2542681 Change-Id: I94b7cde9d10e97ee2c071d92f25555cff5934f0b --- include/netutils/ifc.h | 5 ++-- libnetutils/dhcpclient.c | 15 +++++----- libnetutils/ifc_utils.c | 64 +++++++++++++++++++++++++--------------- 3 files changed, 51 insertions(+), 33 deletions(-) diff --git a/include/netutils/ifc.h b/include/netutils/ifc.h index 650d89d0c..36827ee49 100644 --- a/include/netutils/ifc.h +++ b/include/netutils/ifc.h @@ -38,7 +38,8 @@ extern int ifc_reset_connections(const char *ifname); extern int ifc_get_addr(const char *name, in_addr_t *addr); extern int ifc_set_addr(const char *name, in_addr_t addr); -extern int ifc_set_mask(const char *name, in_addr_t mask); +extern int ifc_get_prefixLength(const char *name, uint32_t *prefixLength); +extern int ifc_set_prefixLength(const char *name, uint32_t prefixLength); extern int ifc_set_hwaddr(const char *name, const void *ptr); /* This function is deprecated. Use ifc_add_route instead. */ @@ -57,7 +58,7 @@ extern int ifc_get_info(const char *name, in_addr_t *addr, in_addr_t *mask, in_addr_t *flags); extern int ifc_configure(const char *ifname, in_addr_t address, - in_addr_t netmask, in_addr_t gateway, + uint32_t prefixLength, in_addr_t gateway, in_addr_t dns1, in_addr_t dns2); __END_DECLS diff --git a/libnetutils/dhcpclient.c b/libnetutils/dhcpclient.c index ff00432b6..5039e26e7 100644 --- a/libnetutils/dhcpclient.c +++ b/libnetutils/dhcpclient.c @@ -93,6 +93,8 @@ const char *ipaddr(in_addr_t addr) return inet_ntoa(in_addr); } +extern int ipv4NetmaskToPrefixLength(in_addr_t mask); + typedef struct dhcp_info dhcp_info; struct dhcp_info { @@ -100,7 +102,7 @@ struct dhcp_info { uint32_t ipaddr; uint32_t gateway; - uint32_t netmask; + uint32_t prefixLength; uint32_t dns1; uint32_t dns2; @@ -111,13 +113,13 @@ struct dhcp_info { dhcp_info last_good_info; -void get_dhcp_info(uint32_t *ipaddr, uint32_t *gateway, uint32_t *mask, +void get_dhcp_info(uint32_t *ipaddr, uint32_t *gateway, uint32_t *prefixLength, uint32_t *dns1, uint32_t *dns2, uint32_t *server, uint32_t *lease) { *ipaddr = last_good_info.ipaddr; *gateway = last_good_info.gateway; - *mask = last_good_info.netmask; + *prefixLength = last_good_info.prefixLength; *dns1 = last_good_info.dns1; *dns2 = last_good_info.dns2; *server = last_good_info.serveraddr; @@ -127,7 +129,7 @@ void get_dhcp_info(uint32_t *ipaddr, uint32_t *gateway, uint32_t *mask, static int dhcp_configure(const char *ifname, dhcp_info *info) { last_good_info = *info; - return ifc_configure(ifname, info->ipaddr, info->netmask, info->gateway, + return ifc_configure(ifname, info->ipaddr, info->prefixLength, info->gateway, info->dns1, info->dns2); } @@ -153,8 +155,7 @@ void dump_dhcp_info(dhcp_info *info) dhcp_type_to_name(info->type), info->type); strcpy(addr, ipaddr(info->ipaddr)); strcpy(gway, ipaddr(info->gateway)); - strcpy(mask, ipaddr(info->netmask)); - LOGD("ip %s gw %s mask %s", addr, gway, mask); + LOGD("ip %s gw %s prefixLength %d", addr, gway, info->prefixLength); if (info->dns1) LOGD("dns1: %s", ipaddr(info->dns1)); if (info->dns2) LOGD("dns2: %s", ipaddr(info->dns2)); LOGD("server %s, lease %d seconds", @@ -196,7 +197,7 @@ int decode_dhcp_msg(dhcp_msg *msg, int len, dhcp_info *info) } switch(opt) { case OPT_SUBNET_MASK: - if (optlen >= 4) memcpy(&info->netmask, x, 4); + if (optlen >= 4) info->prefixLength = ipv4NetmaskToPrefixLength((int)x); break; case OPT_GATEWAY: if (optlen >= 4) memcpy(&info->gateway, x, 4); diff --git a/libnetutils/ifc_utils.c b/libnetutils/ifc_utils.c index 6788391ab..e5c58b9b0 100644 --- a/libnetutils/ifc_utils.c +++ b/libnetutils/ifc_utils.c @@ -51,6 +51,33 @@ static int ifc_ctl_sock = -1; static int ifc_ctl_sock6 = -1; void printerr(char *fmt, ...); +in_addr_t prefixLengthToIpv4Netmask(int prefix_length) +{ + in_addr_t mask = 0; + + // C99 (6.5.7): shifts of 32 bits have undefined results + if (prefix_length <= 0 || prefix_length > 32) { + return 0; + } + + mask = ~mask << (32 - prefix_length); + mask = htonl(mask); + + return mask; +} + +int ipv4NetmaskToPrefixLength(in_addr_t mask) +{ + mask = ntohl(mask); + int prefixLength = 0; + uint32_t m = (uint32_t)mask; + while (m & 0x80000000) { + prefixLength++; + m = m << 1; + } + return prefixLength; +} + static const char *ipaddr_to_string(in_addr_t addr) { struct in_addr in_addr; @@ -179,10 +206,13 @@ 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) +int ifc_set_prefixLength(const char *name, int prefixLength) { struct ifreq ifr; + // TODO - support ipv6 + if (prefixLength > 32 || prefixLength < 0) return -1; + in_addr_t mask = prefixLengthToIpv4Netmask(prefixLength); ifc_init_ifr(name, &ifr); init_sockaddr_in(&ifr.ifr_addr, mask); @@ -206,7 +236,7 @@ int ifc_get_addr(const char *name, in_addr_t *addr) return ret; } -int ifc_get_info(const char *name, in_addr_t *addr, in_addr_t *mask, unsigned *flags) +int ifc_get_info(const char *name, in_addr_t *addr, int *prefixLength, unsigned *flags) { struct ifreq ifr; ifc_init_ifr(name, &ifr); @@ -219,11 +249,12 @@ int ifc_get_info(const char *name, in_addr_t *addr, in_addr_t *mask, unsigned *f } } - if (mask != NULL) { + if (prefixLength != NULL) { if(ioctl(ifc_ctl_sock, SIOCGIFNETMASK, &ifr) < 0) { - *mask = 0; + *prefixLength = 0; } else { - *mask = ((struct sockaddr_in*) &ifr.ifr_addr)->sin_addr.s_addr; + *prefixLength = ipv4NetmaskToPrefixLength((int) + ((struct sockaddr_in*) &ifr.ifr_addr)->sin_addr.s_addr); } } @@ -238,21 +269,6 @@ int ifc_get_info(const char *name, in_addr_t *addr, in_addr_t *mask, unsigned *f return 0; } -in_addr_t get_ipv4_netmask(int prefix_length) -{ - in_addr_t mask = 0; - - // C99 (6.5.7): shifts of 32 bits have undefined results - if (prefix_length == 0) { - return 0; - } - - mask = ~mask << (32 - prefix_length); - mask = htonl(mask); - - return mask; -} - int ifc_add_ipv4_route(const char *ifname, struct in_addr dst, int prefix_length, struct in_addr gw) { @@ -265,7 +281,7 @@ int ifc_add_ipv4_route(const char *ifname, struct in_addr dst, int prefix_length rt.rt_dst.sa_family = AF_INET; rt.rt_dev = (void*) ifname; - netmask = get_ipv4_netmask(prefix_length); + netmask = prefixLengthToIpv4Netmask(prefix_length); init_sockaddr_in(&rt.rt_genmask, netmask); init_sockaddr_in(&rt.rt_dst, dst.s_addr); rt.rt_flags = RTF_UP; @@ -499,7 +515,7 @@ int ifc_remove_default_route(const char *ifname) int ifc_configure(const char *ifname, in_addr_t address, - in_addr_t netmask, + uint32_t prefixLength, in_addr_t gateway, in_addr_t dns1, in_addr_t dns2) { @@ -518,8 +534,8 @@ ifc_configure(const char *ifname, ifc_close(); return -1; } - if (ifc_set_mask(ifname, netmask)) { - printerr("failed to set netmask %s: %s\n", ipaddr_to_string(netmask), strerror(errno)); + if (ifc_set_prefixLength(ifname, prefixLength)) { + printerr("failed to set prefixLength %d: %s\n", prefixLength, strerror(errno)); ifc_close(); return -1; }