diff options
| -rw-r--r-- | ChangeLog | 6 | ||||
| -rw-r--r-- | isys/Makefile | 14 | ||||
| -rw-r--r-- | isys/nl.c | 365 | ||||
| -rw-r--r-- | isys/nl.h | 31 |
4 files changed, 414 insertions, 2 deletions
@@ -1,3 +1,9 @@ +2006-05-23 David Cantrell <dcantrell@redhat.com> + + * isys/Makefile: Add nl.o, glib flags, and a target for nltest. + * isys/nl.h: Netlink helper functions, the header file. + * isys/nl.c: Netlink helper functions, the source file. + 2006-05-23 Chris Lumens <clumens@redhat.com> * bootloader.py (writeBootloader): Don't try to pop the wait window diff --git a/isys/Makefile b/isys/Makefile index 84f743fbe..3ebb0e9b5 100644 --- a/isys/Makefile +++ b/isys/Makefile @@ -4,8 +4,9 @@ CFLAGS += -I$(PYTHONINCLUDE) -I.. -DHAVE_NFS OBJECTS = nfsmount.o nfsmount_clnt.o nfsmount_xdr.o imount.o getmacaddr.o \ smp.o devnodes.o cpio.o uncpio.o dasd.o \ - lang.o isofs.o dns.o linkdetect.o vio.o \ - ethtool.o getipaddr.o wireless.o eddsupport.o + lang.o isofs.o dns.o linkdetect.o vio.o \ + ethtool.o getipaddr.o wireless.o eddsupport.o \ + nl.o SOBJECTS = $(patsubst %.o,%.lo,$(OBJECTS)) SOURCES = $(patsubst %.o,%.c,$(OBJECTS)) isys.c LOADLIBES = -lresolv -lpci -lpopt -lpump -lext2fs -lz -lkudzu -lpci -ldevmapper @@ -14,6 +15,10 @@ PYMODULES = _isys.so SUBDIRS = gzlib DIET = diet +# using glib +LOADLIBES += $(shell pkg-config --libs glib-2.0) +CFLAGS += $(shell pkg-config --cflags glib-2.0) + DOBJECTS = $(patsubst %.o,%.do,$(OBJECTS)) GENERATED = nfs_mountversion.h @@ -64,6 +69,7 @@ clean: rm -f *.o *.so *.lo *.a *.pyc $(TARGET) $(SOBJECTS) $(DOBJECTS) rm -f $(DIETLIBS) $(OBJECTS) $(GENERATED) rm -f .depend + rm -f nl for d in $(SUBDIRS); do make -C $$d clean; done install: all @@ -82,6 +88,10 @@ nfsmount.do: nfs_mountversion.h nfs_mountversion.h: /usr/include/linux/nfs_mount.h grep NFS_MOUNT_VERSION $< | sed -e 's/NFS/KERNEL_NFS/' > $@ +nltest: nl.c nl.h + $(CC) -c $(CFLAGS) -DTESTING nl.c -o nl.o + $(CC) -DTESTING nl.o -o nl $(LOADLIBES) + depend: nfs_mountversion.h $(CPP) -M $(CFLAGS) $(SOURCES) > .depend diff --git a/isys/nl.c b/isys/nl.c new file mode 100644 index 000000000..00ced2cef --- /dev/null +++ b/isys/nl.c @@ -0,0 +1,365 @@ +/* + * nl.c - Netlink helper functions + * + * Copyright 2006 Red Hat, Inc. + * + * David Cantrell <dcantrell@redhat.com> + * + * This software may be freely redistributed under the terms of the GNU + * general public license. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + */ + +#include <stdio.h> +#include <stdlib.h> +#include <errno.h> +#include <string.h> +#include <unistd.h> + +#include <sys/socket.h> +#include <sys/types.h> +#include <linux/netlink.h> +#include <linux/rtnetlink.h> +#include <arpa/inet.h> + +#include <glib.h> + +#include "nl.h" + +/* A linked list of interface_info_t structures (see nl.h) */ +static GSList *interfaces = NULL; + +/** + * Not really Netlink-specific, but handy nonetheless. Takes a MAC address + * and converts it to the familiar hexidecimal notation for easy reading. + * + * @param mac The unsigned char MAC address value. + * @param buf The string to write the formatted address to. + * @return Pointer to buf. + */ +char *netlink_format_mac_addr(char *buf, unsigned char *mac) { + sprintf(buf, "%02x:%02x:%02x:%02x:%02x:%02x", + mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]); + return buf; +} + +/** + * Return a human-readable IP address (either v4 or v6). + * + * @param family The address family. + * @param intf The interface_info_t structure with the IP address info. + * @param buf The buffer to write the formatted IP address to. + * @return A pointer to buf. + */ +char *netlink_format_ip_addr(int family, interface_info_t *intf, char *buf) { + char ipbuf[256]; + + memset(ipbuf, 0, sizeof(ipbuf)); + switch (family) { + case AF_INET: + inet_ntop(family, &(intf->ip_addr), ipbuf, sizeof(ipbuf)); + break; + case AF_INET6: + inet_ntop(family, &(intf->ip6_addr), ipbuf, sizeof(ipbuf)); + break; + } + + memcpy(buf, ipbuf, sizeof(ipbuf)); + return buf; +} + +/** + * Create a new PF_NETLINK socket for communication with the kernel Netlink + * layer. Open with NETLINK_ROUTE protocol since we want IPv4 and IPv6 + * interface, address, and routing information. + * + * @return Handle to new socket or -1 on error. + */ +int netlink_create_socket(void) { + int sock; + + sock = socket(PF_NETLINK, SOCK_RAW, NETLINK_ROUTE); + if (sock < 0) { + perror("netlink socket"); + return -1; + } + + return sock; +} + +/** + * Send a dump request message for the specified information in the + * specified family type. Family may be AF_INET or AF_INET6, for + * example. The request type should be a GET type as specified in + * /usr/include/linux/rtnetlink.h (for example, RTM_GETLINK). + * + * @param sock The Netlink socket to use. + * @param type The Netlink request type. + * @param family The address family. + * @return The number of characters sent or -1 on error. + */ +int netlink_send_dump_request(int sock, int type, int family) { + int ret; + char buf[4096]; + struct sockaddr_nl snl; + struct nlmsghdr *nlh; + struct rtgenmsg *g; + + memset(&snl, 0, sizeof(snl)); + snl.nl_family = AF_NETLINK; + + memset(buf, 0, sizeof(buf)); + nlh = (struct nlmsghdr *)buf; + g = (struct rtgenmsg *)(buf + sizeof(struct nlmsghdr)); + + nlh->nlmsg_len = NLMSG_LENGTH(sizeof(struct rtgenmsg)); + nlh->nlmsg_flags = NLM_F_REQUEST|NLM_F_DUMP; + nlh->nlmsg_type = type; + g->rtgen_family = family; + + ret = sendto(sock, buf, nlh->nlmsg_len, 0, (struct sockaddr *)&snl, + sizeof(snl)); + if (ret < 0) { + perror("netlink_send_dump_request sendto"); + return -1; + } + + return ret; +} + +/** + * Look for an IP address for the given interface. + * + * @param index The interface index number. + * @param family The address family (AF_INET or AF_INET6). + * @param addr Pointer to where we should write the IP address. + * @return -1 on error, 0 on success. + */ +int netlink_get_interface_ip(int index, int family, void *addr) { + int sock, ret, len, alen; + char buf[4096]; + struct nlmsghdr *nlh; + struct ifaddrmsg *ifa; + struct rtattr *rta; + struct rtattr *tb[IFLA_MAX+1]; + + /* get a socket */ + if ((sock = netlink_create_socket()) == -1) { + perror("netlink_create_socket in netlink_get_interface_ip"); + close(sock); + return -1; + } + + /* send dump request */ + if (netlink_send_dump_request(sock, RTM_GETADDR, family) == -1) { + perror("netlink_send_dump_request in netlink_get_interface_ip"); + close(sock); + return -1; + } + + /* read back messages */ + memset(buf, 0, sizeof(buf)); + ret = recvfrom(sock, buf, sizeof(buf), 0, NULL, 0); + if (ret < 0) { + perror("recvfrom in netlink_init_interfaces_table"); + close(sock); + return -1; + } + + nlh = (struct nlmsghdr *) buf; + while (NLMSG_OK(nlh, ret)) { + switch (nlh->nlmsg_type) { + case NLMSG_DONE: + break; + case RTM_NEWADDR: + break; + default: + nlh = NLMSG_NEXT(nlh, ret); + continue; + } + + /* RTM_NEWADDR */ + ifa = NLMSG_DATA(nlh); + rta = IFA_RTA(ifa); + len = NLMSG_PAYLOAD(nlh, 0); /* IFA_PAYLOAD(nlh) ???? */ + + if (ifa->ifa_family != family) { + nlh = NLMSG_NEXT(nlh, ret); + continue; + } + + while (RTA_OK(rta, len)) { + if (rta->rta_type <= len) + tb[rta->rta_type] = rta; + rta = RTA_NEXT(rta, len); + } + + alen = RTA_PAYLOAD(tb[IFA_ADDRESS]); + + /* write the address */ + if (tb[IFA_ADDRESS] && ifa->ifa_index == index) { + memset(addr, 0, sizeof(*addr)); + switch (family) { + case AF_INET: + memcpy(addr, (struct in_addr *)RTA_DATA(tb[IFA_ADDRESS]), alen); + break; + case AF_INET6: + memcpy(addr, (struct in6_addr *)RTA_DATA(tb[IFA_ADDRESS]), alen); + break; + } + + close(sock); + return 0; + } + + /* next netlink msg */ + nlh = NLMSG_NEXT(nlh, ret); + } + + close(sock); + return 0; +} + +/** + * Initialize the interfaces linked list with the interface name, MAC + * address, and IP addresses. This function is only called once to + * initialize the structure, but may be called again if the structure + * should be reinitialized. + * + * @return 0 on succes, -1 on error. + */ +int netlink_init_interfaces_list(void) { + int sock, ret, len, alen, r; + char buf[4096]; + struct nlmsghdr *nlh; + struct ifinfomsg *ifi; + struct rtattr *rta; + struct rtattr *tb[IFLA_MAX+1]; + interface_info_t *intfinfo; + + /* get a socket */ + if ((sock = netlink_create_socket()) == -1) { + perror("netlink_create_socket in netlink_init_interfaces_table"); + close(sock); + return -1; + } + + /* send dump request */ + if (netlink_send_dump_request(sock, RTM_GETLINK, AF_NETLINK) == -1) { + perror("netlink_send_dump_request in netlink_init_interfaces_table"); + close(sock); + return -1; + } + + /* read back messages */ + memset(buf, 0, sizeof(buf)); + ret = recvfrom(sock, buf, sizeof(buf), 0, NULL, 0); + if (ret < 0) { + perror("recvfrom in netlink_init_interfaces_table"); + close(sock); + return -1; + } + + nlh = (struct nlmsghdr *) buf; + while (NLMSG_OK(nlh, ret)) { + switch (nlh->nlmsg_type) { + case NLMSG_DONE: + break; + case RTM_NEWLINK: + break; + default: + nlh = NLMSG_NEXT(nlh, ret); + continue; + } + + /* RTM_NEWLINK */ + memset(tb, 0, sizeof(tb)); + memset(tb, 0, sizeof(struct rtattr *) * (IFLA_MAX + 1)); + + ifi = NLMSG_DATA(nlh); + rta = IFLA_RTA(ifi); + len = IFLA_PAYLOAD(nlh); + + while (RTA_OK(rta, len)) { + if (rta->rta_type <= len) + tb[rta->rta_type] = rta; + rta = RTA_NEXT(rta, len); + } + + alen = RTA_PAYLOAD(tb[IFLA_ADDRESS]); + + /* we have an ethernet MAC addr if alen=6 */ + if (alen == 6) { + /* make some room! */ + intfinfo = malloc(sizeof(struct _interface_info_t)); + if (intfinfo == NULL) { + perror("malloc in netlink_init_interfaces_table"); + close(sock); + return -1; + } + + /* copy the interface index */ + intfinfo->i = ifi->ifi_index; + + /* copy the interface name (eth0, eth1, ...) */ + intfinfo->name = strndup((char *) RTA_DATA(tb[IFLA_IFNAME]), + sizeof(RTA_DATA(tb[IFLA_IFNAME]))); + + /* copy the MAC addr */ + memcpy(&intfinfo->mac, RTA_DATA(tb[IFLA_ADDRESS]), alen); + + /* get the IPv4 address of this interface (if any) */ + r = netlink_get_interface_ip(intfinfo->i, AF_INET, &intfinfo->ip_addr); + if (r == -1) + intfinfo->ip_addr.s_addr = 0; + + /* get the IPv6 address of this interface (if any) */ + r = netlink_get_interface_ip(intfinfo->i,AF_INET6,&intfinfo->ip6_addr); +/* XXX: why this no work? + if (r == -1) + intfinfo->ip6_addr.s6_addr = 0; +*/ + + /* add this interface */ + interfaces = g_slist_append(interfaces, intfinfo); + } + + /* next netlink msg */ + nlh = NLMSG_NEXT(nlh, ret); + } + + close(sock); + return 0; +} + +#ifdef TESTING +void print_interfaces(gpointer data, gpointer user_data) { + char buf[20]; + char ipbuf[256]; + interface_info_t *intf; + + intf = (interface_info_t *) data; + printf("Interface %d\n", intf->i); + printf(" Name: %s\n", intf->name); + printf(" IPv4: %s\n", netlink_format_ip_addr(AF_INET, intf, ipbuf)); + printf(" IPv6: %s\n", netlink_format_ip_addr(AF_INET6, intf, ipbuf)); + printf(" MAC: %s\n\n", netlink_format_mac_addr(buf, intf->mac)); + + return; +} + +int main(void) { + if (netlink_init_interfaces_list() == -1) { + fprintf(stderr, "netlink_init_interfaces_list failure: %s\n", __func__); + fflush(stderr); + return EXIT_FAILURE; + } + + g_slist_foreach(interfaces, print_interfaces, NULL); + + return EXIT_SUCCESS; +} +#endif diff --git a/isys/nl.h b/isys/nl.h new file mode 100644 index 000000000..46e70313a --- /dev/null +++ b/isys/nl.h @@ -0,0 +1,31 @@ +/* + * nl.h - Netlink helper functions, the header file + * + * Copyright 2006 Red Hat, Inc. + * + * David Cantrell <dcantrell@redhat.com> + * + * This software may be freely redistributed under the terms of the GNU + * general public license. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + */ + +/* Information per interface */ +typedef struct _interface_info_t { + int i; /* interface index */ + char *name; /* name (eth0, eth1, ...) */ + struct in_addr ip_addr; /* IPv4 address (0=none) */ + struct in6_addr ip6_addr; /* IPv6 address (0=none) */ + unsigned char mac[8]; /* MAC address */ +} interface_info_t; + +/* Function prototypes */ +char *netlink_format_mac_addr(char *buf, unsigned char *mac); +char *netlink_format_ip_addr(int family, interface_info_t *intf, char *buf); +int netlink_create_socket(void); +int netlink_send_dump_request(int sock, int type, int family); +int netlink_get_interface_ip(int index, int family, void *addr); +int netlink_init_interfaces_list(void); |