snmpTCPDomain.c
上传用户:wxp200602
上传日期:2007-10-30
资源大小:4028k
文件大小:11k
- #include <net-snmp/net-snmp-config.h>
- #include <stdio.h>
- #include <sys/types.h>
- #include <errno.h>
- #if HAVE_STRING_H
- #include <string.h>
- #else
- #include <strings.h>
- #endif
- #if HAVE_STDLIB_H
- #include <stdlib.h>
- #endif
- #if HAVE_UNISTD_H
- #include <unistd.h>
- #endif
- #if HAVE_SYS_SOCKET_H
- #include <sys/socket.h>
- #endif
- #if HAVE_NETINET_IN_H
- #include <netinet/in.h>
- #endif
- #if HAVE_ARPA_INET_H
- #include <arpa/inet.h>
- #endif
- #if HAVE_FCNTL_H
- #include <fcntl.h>
- #endif
- #if HAVE_WINSOCK_H
- #include <winsock2.h>
- #include <ws2tcpip.h>
- #endif
- #if HAVE_DMALLOC_H
- #include <dmalloc.h>
- #endif
- #include <net-snmp/types.h>
- #include <net-snmp/output_api.h>
- #include <net-snmp/library/snmp_transport.h>
- #include <net-snmp/library/snmpUDPDomain.h>
- #include <net-snmp/library/snmpTCPDomain.h>
- oid netsnmp_snmpTCPDomain[] = { TRANSPORT_DOMAIN_TCP_IP };
- static netsnmp_tdomain tcpDomain;
- /*
- * Return a string representing the address in data, or else the "far end"
- * address if data is NULL.
- */
- static char *
- netsnmp_tcp_fmtaddr(netsnmp_transport *t, void *data, int len)
- {
- struct sockaddr_in *to = NULL;
- if (data != NULL && len == sizeof(struct sockaddr_in)) {
- to = (struct sockaddr_in *) data;
- } else if (t != NULL && t->data != NULL &&
- t->data_length == sizeof(struct sockaddr_in)) {
- to = (struct sockaddr_in *) t->data;
- }
- if (to == NULL) {
- return strdup("TCP: unknown");
- } else {
- char tmp[64];
- sprintf(tmp, "TCP: [%s]:%hd",
- inet_ntoa(to->sin_addr), ntohs(to->sin_port));
- return strdup(tmp);
- }
- }
- /*
- * You can write something into opaque that will subsequently get passed back
- * to your send function if you like. For instance, you might want to
- * remember where a PDU came from, so that you can send a reply there...
- */
- static int
- netsnmp_tcp_recv(netsnmp_transport *t, void *buf, int size,
- void **opaque, int *olength)
- {
- int rc = -1;
- if (t != NULL && t->sock >= 0) {
- while (rc < 0) {
- rc = recv(t->sock, buf, size, 0);
- if (rc < 0 && errno != EINTR) {
- DEBUGMSGTL(("netsnmp_tcp", "recv fd %d err %d ("%s")n",
- t->sock, errno, strerror(errno)));
- break;
- }
- DEBUGMSGTL(("netsnmp_tcp", "recv fd %d got %d bytesn",
- t->sock, rc));
- }
- } else {
- return -1;
- }
- if (opaque != NULL && olength != NULL) {
- if (t->data_length > 0) {
- if ((*opaque = malloc(t->data_length)) != NULL) {
- memcpy(*opaque, t->data, t->data_length);
- *olength = t->data_length;
- } else {
- *olength = 0;
- }
- } else {
- *opaque = NULL;
- *olength = 0;
- }
- }
- return rc;
- }
- static int
- netsnmp_tcp_send(netsnmp_transport *t, void *buf, int size,
- void **opaque, int *olength)
- {
- int rc = -1;
- if (t != NULL && t->sock >= 0) {
- while (rc < 0) {
- rc = send(t->sock, buf, size, 0);
- if (rc < 0 && errno != EINTR) {
- break;
- }
- }
- }
- return rc;
- }
- static int
- netsnmp_tcp_close(netsnmp_transport *t)
- {
- int rc = -1;
- if (t != NULL && t->sock >= 0) {
- DEBUGMSGTL(("netsnmp_tcp", "close fd %dn", t->sock));
- #ifndef HAVE_CLOSESOCKET
- rc = close(t->sock);
- #else
- rc = closesocket(t->sock);
- #endif
- t->sock = -1;
- }
- return rc;
- }
- static int
- netsnmp_tcp_accept(netsnmp_transport *t)
- {
- struct sockaddr *farend = NULL;
- int newsock = -1, sockflags = 0;
- socklen_t farendlen = sizeof(struct sockaddr_in);
- char *str = NULL;
- farend = (struct sockaddr *) malloc(sizeof(struct sockaddr_in));
- if (farend == NULL) {
- /*
- * Indicate that the acceptance of this socket failed.
- */
- DEBUGMSGTL(("netsnmp_tcp", "accept: malloc failedn"));
- return -1;
- }
- if (t != NULL && t->sock >= 0) {
- newsock = accept(t->sock, farend, &farendlen);
- if (newsock < 0) {
- DEBUGMSGTL(("netsnmp_tcp", "accept failed rc %d errno %d "%s"n",
- newsock, errno, strerror(errno)));
- free(farend);
- return newsock;
- }
- if (t->data != NULL) {
- free(t->data);
- }
- t->data = farend;
- t->data_length = farendlen;
- str = netsnmp_tcp_fmtaddr(NULL, farend, farendlen);
- DEBUGMSGTL(("netsnmp_tcp", "accept succeeded (from %s)n", str));
- free(str);
- /*
- * Try to make the new socket blocking.
- */
- #ifdef WIN32
- ioctlsocket(newsock, FIONBIO, &sockflags);
- #else
- if ((sockflags = fcntl(newsock, F_GETFL, 0)) >= 0) {
- fcntl(newsock, F_SETFL, (sockflags & ~O_NONBLOCK));
- } else {
- DEBUGMSGTL(("netsnmp_tcp", "couldn't f_getfl of fd %dn",newsock));
- }
- #endif
- /*
- * Allow user to override the send and receive buffers. Default is
- * to use os default. Don't worry too much about errors --
- * just plough on regardless.
- */
- netsnmp_sock_buffer_set(newsock, SO_SNDBUF, 1, 0);
- netsnmp_sock_buffer_set(newsock, SO_RCVBUF, 1, 0);
- return newsock;
- } else {
- free(farend);
- return -1;
- }
- }
- /*
- * Open a TCP-based transport for SNMP. Local is TRUE if addr is the local
- * address to bind to (i.e. this is a server-type session); otherwise addr is
- * the remote address to send things to.
- */
- netsnmp_transport *
- netsnmp_tcp_transport(struct sockaddr_in *addr, int local)
- {
- netsnmp_transport *t = NULL;
- int rc = 0;
- if (addr == NULL || addr->sin_family != AF_INET) {
- return NULL;
- }
- t = (netsnmp_transport *) malloc(sizeof(netsnmp_transport));
- if (t == NULL) {
- return NULL;
- }
- memset(t, 0, sizeof(netsnmp_transport));
- t->data = malloc(sizeof(struct sockaddr_in));
- if (t->data == NULL) {
- netsnmp_transport_free(t);
- return NULL;
- }
- t->data_length = sizeof(struct sockaddr_in);
- memcpy(t->data, addr, sizeof(struct sockaddr_in));
- t->domain = netsnmp_snmpTCPDomain;
- t->domain_length =
- sizeof(netsnmp_snmpTCPDomain) / sizeof(netsnmp_snmpTCPDomain[0]);
- t->sock = socket(PF_INET, SOCK_STREAM, 0);
- if (t->sock < 0) {
- netsnmp_transport_free(t);
- return NULL;
- }
- t->flags = NETSNMP_TRANSPORT_FLAG_STREAM;
- if (local) {
- int sockflags = 0, opt = 1;
- /*
- * This session is inteneded as a server, so we must bind to the given
- * IP address (which may include an interface address, or could be
- * INADDR_ANY, but will always include a port number.
- */
- t->flags |= NETSNMP_TRANSPORT_FLAG_LISTEN;
- t->local = malloc(6);
- if (t->local == NULL) {
- netsnmp_tcp_close(t);
- netsnmp_transport_free(t);
- return NULL;
- }
- memcpy(t->local, (u_char *) & (addr->sin_addr.s_addr), 4);
- t->local[4] = (htons(addr->sin_port) & 0xff00) >> 8;
- t->local[5] = (htons(addr->sin_port) & 0x00ff) >> 0;
- t->local_length = 6;
- /*
- * We should set SO_REUSEADDR too.
- */
- setsockopt(t->sock, SOL_SOCKET, SO_REUSEADDR, (void *)&opt,
- sizeof(opt));
- rc = bind(t->sock, (struct sockaddr *)addr, sizeof(struct sockaddr));
- if (rc != 0) {
- netsnmp_tcp_close(t);
- netsnmp_transport_free(t);
- return NULL;
- }
- /*
- * Since we are going to be letting select() tell us when connections
- * are ready to be accept()ed, we need to make the socket n0n-blocking
- * to avoid the race condition described in W. R. Stevens, ``Unix
- * Network Programming Volume I Second Edition'', pp. 422--4, which
- * could otherwise wedge the agent.
- */
- #ifdef WIN32
- opt = 1;
- ioctlsocket(t->sock, FIONBIO, &opt);
- #else
- sockflags = fcntl(t->sock, F_GETFL, 0);
- fcntl(t->sock, F_SETFL, sockflags | O_NONBLOCK);
- #endif
- /*
- * Now sit here and wait for connections to arrive.
- */
- rc = listen(t->sock, NETSNMP_STREAM_QUEUE_LEN);
- if (rc != 0) {
- netsnmp_tcp_close(t);
- netsnmp_transport_free(t);
- return NULL;
- }
-
- /*
- * no buffer size on listen socket - doesn't make sense
- */
- } else {
- t->remote = malloc(6);
- if (t->remote == NULL) {
- netsnmp_tcp_close(t);
- netsnmp_transport_free(t);
- return NULL;
- }
- memcpy(t->remote, (u_char *) & (addr->sin_addr.s_addr), 4);
- t->remote[4] = (htons(addr->sin_port) & 0xff00) >> 8;
- t->remote[5] = (htons(addr->sin_port) & 0x00ff) >> 0;
- t->remote_length = 6;
- /*
- * This is a client-type session, so attempt to connect to the far
- * end. We don't go non-blocking here because it's not obvious what
- * you'd then do if you tried to do snmp_sends before the connection
- * had completed. So this can block.
- */
- rc = connect(t->sock, (struct sockaddr *)addr,
- sizeof(struct sockaddr));
- if (rc < 0) {
- netsnmp_tcp_close(t);
- netsnmp_transport_free(t);
- return NULL;
- }
- /*
- * Allow user to override the send and receive buffers. Default is
- * to use os default. Don't worry too much about errors --
- * just plough on regardless.
- */
- netsnmp_sock_buffer_set(t->sock, SO_SNDBUF, local, 0);
- netsnmp_sock_buffer_set(t->sock, SO_RCVBUF, local, 0);
- }
- /*
- * Message size is not limited by this transport (hence msgMaxSize
- * is equal to the maximum legal size of an SNMP message).
- */
- t->msgMaxSize = 0x7fffffff;
- t->f_recv = netsnmp_tcp_recv;
- t->f_send = netsnmp_tcp_send;
- t->f_close = netsnmp_tcp_close;
- t->f_accept = netsnmp_tcp_accept;
- t->f_fmtaddr = netsnmp_tcp_fmtaddr;
- return t;
- }
- netsnmp_transport *
- netsnmp_tcp_create_tstring(const char *str, int local)
- {
- struct sockaddr_in addr;
- if (netsnmp_sockaddr_in(&addr, str, 0)) {
- return netsnmp_tcp_transport(&addr, local);
- } else {
- return NULL;
- }
- }
- netsnmp_transport *
- netsnmp_tcp_create_ostring(const u_char * o, size_t o_len, int local)
- {
- struct sockaddr_in addr;
- if (o_len == 6) {
- unsigned short porttmp = (o[4] << 8) + o[5];
- addr.sin_family = AF_INET;
- memcpy((u_char *) & (addr.sin_addr.s_addr), o, 4);
- addr.sin_port = htons(porttmp);
- return netsnmp_tcp_transport(&addr, local);
- }
- return NULL;
- }
- void
- netsnmp_tcp_ctor(void)
- {
- tcpDomain.name = netsnmp_snmpTCPDomain;
- tcpDomain.name_length = sizeof(netsnmp_snmpTCPDomain) / sizeof(oid);
- tcpDomain.prefix = calloc(2, sizeof(char *));
- tcpDomain.prefix[0] = "tcp";
- tcpDomain.f_create_from_tstring = netsnmp_tcp_create_tstring;
- tcpDomain.f_create_from_ostring = netsnmp_tcp_create_ostring;
- netsnmp_tdomain_register(&tcpDomain);
- }