blob: 8cb6f94d2d3b71271862ec93b09f0235ff0935fe [file] [log] [blame]
#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>
/* Copied from snmpUDPDomain.c */
typedef struct netsnmp_udp_addr_pair_s {
struct sockaddr_in remote_addr;
struct in_addr local_addr;
} netsnmp_udp_addr_pair;
oid netsnmp_snmpTCPDomain[] = { TRANSPORT_DOMAIN_TCP_IP };
static netsnmp_tdomain tcpDomain;
/*
* Not static since it is needed here as well as in snmpUDPDomain, but not
* public either
*/
int
netsnmp_sockaddr_in2(struct sockaddr_in *addr,
const char *inpeername, const char *default_target);
/*
* 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)
{
netsnmp_udp_addr_pair *addr_pair = NULL;
if (data != NULL && len == sizeof(netsnmp_udp_addr_pair)) {
addr_pair = (netsnmp_udp_addr_pair *) data;
} else if (t != NULL && t->data != NULL) {
addr_pair = (netsnmp_udp_addr_pair *) t->data;
}
if (addr_pair == NULL) {
return strdup("TCP: unknown");
} else {
struct sockaddr_in *to = NULL;
char tmp[64];
to = (struct sockaddr_in *) &(addr_pair->remote_addr);
if (to == NULL) {
return strdup("TCP: unknown");
}
sprintf(tmp, "TCP: [%s]:%hu",
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 = recvfrom(t->sock, buf, size, 0, NULL, 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 bytes\n",
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 = sendto(t->sock, buf, size, 0, NULL, 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 %d\n", 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;
netsnmp_udp_addr_pair *addr_pair = NULL;
int newsock = -1;
#ifdef WIN32
u_long ioctlsocket_opt;
#else
int sockflags;
#endif
socklen_t farendlen = sizeof(struct sockaddr_in);
char *str = NULL;
addr_pair = (netsnmp_udp_addr_pair *)malloc(sizeof(netsnmp_udp_addr_pair));
if (addr_pair == NULL) {
/*
* Indicate that the acceptance of this socket failed.
*/
DEBUGMSGTL(("netsnmp_tcp", "accept: malloc failed\n"));
return -1;
}
farend = (struct sockaddr *) &(addr_pair->remote_addr);
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 = addr_pair;
t->data_length = sizeof(netsnmp_udp_addr_pair);
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_opt = 0;
ioctlsocket(newsock, FIONBIO, &ioctlsocket_opt);
#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 %d\n",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;
netsnmp_udp_addr_pair *addr_pair = 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));
addr_pair = (netsnmp_udp_addr_pair *)malloc(sizeof(netsnmp_udp_addr_pair));
if (addr_pair == NULL) {
netsnmp_transport_free(t);
return NULL;
}
t->data = addr_pair;
t->data_length = sizeof(netsnmp_udp_addr_pair);
memcpy(&(addr_pair->remote_addr), 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) {
#ifdef WIN32
u_long ioctlsocket_opt = 1;
#else
int sockflags = 0;
#endif
int 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 = (u_char *)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
ioctlsocket_opt = 1;
ioctlsocket(t->sock, FIONBIO, &ioctlsocket_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 = (u_char *)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,
const char *default_target)
{
struct sockaddr_in addr;
if (netsnmp_sockaddr_in2(&addr, str, default_target)) {
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 = (const char **)calloc(2, sizeof(char *));
tcpDomain.prefix[0] = "tcp";
tcpDomain.f_create_from_tstring = NULL;
tcpDomain.f_create_from_tstring_new = netsnmp_tcp_create_tstring;
tcpDomain.f_create_from_ostring = netsnmp_tcp_create_ostring;
netsnmp_tdomain_register(&tcpDomain);
}