diff options
Diffstat (limited to 'agent/mibgroup/ip-mib/data_access/defaultrouter_linux.c')
| -rw-r--r-- | agent/mibgroup/ip-mib/data_access/defaultrouter_linux.c | 328 |
1 files changed, 328 insertions, 0 deletions
diff --git a/agent/mibgroup/ip-mib/data_access/defaultrouter_linux.c b/agent/mibgroup/ip-mib/data_access/defaultrouter_linux.c new file mode 100644 index 0000000..5a1fa46 --- /dev/null +++ b/agent/mibgroup/ip-mib/data_access/defaultrouter_linux.c @@ -0,0 +1,328 @@ +/* + * Interface MIB architecture support + * + * $Id:$ + */ +#include <net-snmp/net-snmp-config.h> +#include <net-snmp/net-snmp-includes.h> + +#include <net-snmp/agent/net-snmp-agent-includes.h> +#include <net-snmp/data_access/defaultrouter.h> + +#include "ip-mib/ipDefaultRouterTable/ipDefaultRouterTable.h" + +#include <asm/types.h> +#ifdef HAVE_LINUX_RTNETLINK_H +#include <linux/netlink.h> +#include <linux/rtnetlink.h> +#endif +#include <sys/socket.h> +#include <arpa/inet.h> +#include <errno.h> +#include <unistd.h> + +#define RCVBUF_SIZE 32768 +#define SNDBUF_SIZE 512 + +#ifdef NETSNMP_ENABLE_IPV6 +#define DR_ADDRSTRLEN INET6_ADDRSTRLEN +#else +#define DR_ADDRSTRLEN INET_ADDRSTRLEN +#endif + +/**---------------------------------------------------------------------*/ +/* + * local static prototypes + */ +static int _load(netsnmp_container *container); + + +/* + * initialize arch specific storage + * + * @retval 0: success + * @retval <0: error + */ +int +netsnmp_arch_defaultrouter_entry_init(netsnmp_defaultrouter_entry *entry) +{ + /* + * init + */ + return 0; +} + +/** + * + * @retval 0 no errors + * @retval !0 errors + */ +int +netsnmp_arch_defaultrouter_container_load(netsnmp_container *container, + u_int load_flags) +{ + int rc = 0; + + DEBUGMSGTL(("access:defaultrouter:entry:arch", "load (linux)\n")); + + rc = _load(container); + if (rc < 0) { + u_int flags = NETSNMP_ACCESS_DEFAULTROUTER_FREE_KEEP_CONTAINER; + netsnmp_access_defaultrouter_container_free(container, flags); + } + + return rc; +} + +/** + * + * @retval 0 no errors + * @retval !0 errors + */ +static int +_load(netsnmp_container *container) +{ +#ifndef HAVE_LINUX_RTNETLINK_H + DEBUGMSGTL(("access:defaultrouter", + "cannot get default router information" + "as netlink socket is not available\n")); + return -1; +#else + int rc = 0; + int idx_offset = 0; + netsnmp_defaultrouter_entry *entry; + int nlsk; + struct sockaddr_nl addr; + int rcvbuf_size = RCVBUF_SIZE; + unsigned char rcvbufmem[RCVBUF_SIZE + sizeof(intmax_t)]; + unsigned char sndbufmem[SNDBUF_SIZE + sizeof(intmax_t)]; + /* + * Buffers must be memory aligned. + * Message structure internal alignment is maintained by the netlink API. + */ + unsigned char *rcvbuf = rcvbufmem + + sizeof(intmax_t) - (((intptr_t)rcvbufmem) % sizeof(intmax_t)); + unsigned char *sndbuf = sndbufmem + + sizeof(intmax_t) - (((intptr_t)sndbufmem) % sizeof(intmax_t)); + struct nlmsghdr *hdr; + struct rtmsg *rthdr; + int count; + int end_of_message = 0; + long hz = sysconf(_SC_CLK_TCK); + + netsnmp_assert(NULL != container); + + /* + * Open a netlink socket + */ + nlsk = socket(AF_NETLINK, SOCK_DGRAM, NETLINK_ROUTE); + if (nlsk < 0) { + snmp_log(LOG_ERR, "Could not open netlink socket : %s\n", + strerror(errno)); + return -1; + } + + if (setsockopt(nlsk, SOL_SOCKET, SO_RCVBUF, + &rcvbuf_size, sizeof(rcvbuf_size)) < 0) { + snmp_log(LOG_ERR, "Could not open netlink socket : %s\n", + strerror(errno)); + close(nlsk); + return -1; + } + + memset(&addr, '\0', sizeof(struct sockaddr_nl)); + addr.nl_family = AF_NETLINK; + + memset(sndbuf, '\0', SNDBUF_SIZE); + hdr = (struct nlmsghdr *)sndbuf; + hdr->nlmsg_type = RTM_GETROUTE; + hdr->nlmsg_pid = getpid(); + hdr->nlmsg_seq = 0; + hdr->nlmsg_flags = NLM_F_ROOT | NLM_F_MATCH | NLM_F_REQUEST; + hdr->nlmsg_len = NLMSG_LENGTH(sizeof(struct rtmsg)); + rthdr = (struct rtmsg *)NLMSG_DATA(hdr); + rthdr->rtm_table = RT_TABLE_MAIN; + + /* + * Send a request to the kernel to dump the routing table to us + */ + count = sendto(nlsk, sndbuf, hdr->nlmsg_len, 0, + (struct sockaddr *)&addr, sizeof(struct sockaddr_nl)); + if (count < 0) { + snmp_log(LOG_ERR, "unable to send netlink message to kernel : %s\n", + strerror(errno)); + close(nlsk); + return -2; + } + + /* + * Now listen for response + */ + do { + struct nlmsghdr *nlmhp; + struct rtmsg *rtmp; + struct rtattr *rtap; + struct rta_cacheinfo *rtci; + socklen_t sock_len; + int rtcount; + + memset(rcvbuf, '\0', RCVBUF_SIZE); + sock_len = sizeof(struct sockaddr_nl); + + /* + * Get the message + */ + count = recvfrom(nlsk, rcvbuf, RCVBUF_SIZE, 0, + (struct sockaddr *)&addr, &sock_len); + if (count < 0) { + snmp_log(LOG_ERR, "unable to receive netlink messages: %s\n", + strerror(errno)); + rc = -1; + break; + } + + /* + * Walk all of the returned messages + */ + nlmhp = (struct nlmsghdr *)rcvbuf; + while (NLMSG_OK(nlmhp, count)) { + u_char addresstype; + char address[NETSNMP_ACCESS_DEFAULTROUTER_BUF_SIZE + 1]; + size_t address_len = 0; + int if_index = -1; + u_long lifetime = 0; + int preference = -3; + + /* + * Make sure the message is ok + */ + if (nlmhp->nlmsg_type == NLMSG_ERROR) { + snmp_log(LOG_ERR, "kernel produced nlmsg err\n"); + rc = -1; + break; + } + + /* + * End of message, we're done + */ + if (nlmhp->nlmsg_type & NLMSG_DONE) { + end_of_message = 1; + break; + } + + /* + * Get the pointer to the rtmsg struct + */ + rtmp = NLMSG_DATA(nlmhp); + + /* + * zero length destination is a default route + */ + if (rtmp->rtm_dst_len != 0) + goto next_nlmsghdr; + + /* + * Start scanning the attributes for needed info + */ + if (rtmp->rtm_family == AF_INET) { + addresstype = INETADDRESSTYPE_IPV4; + lifetime = IPDEFAULTROUTERLIFETIME_MAX; /* infinity */ + } +#ifdef NETSNMP_ENABLE_IPV6 + else if (rtmp->rtm_family == AF_INET6) { + addresstype = INETADDRESSTYPE_IPV6; + /* router lifetime for IPv6 is retrieved by RTA_CACHEINFO */ + lifetime = 0; + } +#endif + else + goto next_nlmsghdr; /* skip, we don't care about this route */ + + preference = 0; /* preference is medium(0) for now */ + + rtap = RTM_RTA(rtmp); + rtcount = RTM_PAYLOAD(nlmhp); + while (RTA_OK(rtap, rtcount)) { + switch (rtap->rta_type) { + case RTA_OIF: + if_index = *(int *)(RTA_DATA(rtap)); + break; + + case RTA_GATEWAY: + address_len = RTA_PAYLOAD(rtap); + memset(address, '\0', sizeof(address)); + memcpy(address, RTA_DATA(rtap), address_len); + break; + +#ifdef NETSNMP_ENABLE_IPV6 + case RTA_CACHEINFO: + rtci = RTA_DATA(rtap); + if ((rtmp->rtm_flags & RTM_F_CLONED) || + (rtci && rtci->rta_expires)) { + lifetime = rtci->rta_expires / hz; + } + break; +#endif + + default: + break; + } /* switch */ + + rtap = RTA_NEXT(rtap, rtcount); + } /* while RTA_OK(rtap) */ + + if (address_len != 0 && if_index != -1 && + lifetime != 0 && preference != -3 ) { + DEBUGIF("access:defaultrouter") { + char addr_str[DR_ADDRSTRLEN]; + memset(addr_str, '\0', DR_ADDRSTRLEN); + + if (rtmp->rtm_family == AF_INET) + inet_ntop(AF_INET, address, addr_str, DR_ADDRSTRLEN); +#ifdef NETSNMP_ENABLE_IPV6 + else + inet_ntop(AF_INET6, address, addr_str, DR_ADDRSTRLEN); +#endif + DEBUGMSGTL(("access:defaultrouter", + "found default route: %s if_index %d " + "lifetime %lu preference %d\n", + addr_str, if_index, lifetime, preference)); + } + + entry = netsnmp_access_defaultrouter_entry_create(); + if (NULL == entry) { + rc = -3; + break; + } + + entry->ns_dr_index = ++idx_offset; + entry->dr_addresstype = addresstype; + entry->dr_address_len = address_len; + memcpy(entry->dr_address, address, + NETSNMP_ACCESS_DEFAULTROUTER_BUF_SIZE); + entry->dr_if_index = if_index; + entry->dr_lifetime = lifetime; + entry->dr_preference = preference; + + if (CONTAINER_INSERT(container, entry) < 0) + { + DEBUGMSGTL(("access:arp:container", + "error with defaultrouter_entry: " + "insert into container failed.\n")); + netsnmp_access_defaultrouter_entry_free(entry); + } + } + +next_nlmsghdr: + nlmhp = NLMSG_NEXT(nlmhp, count); + } /* while NLMSG_OK(nlmhp) */ + + if (rc < 0) + break; + + } while (!end_of_message); + + close(nlsk); + return rc; +#endif /* HAVE_LINUX_RTNETLINK_H */ +} |