#include <net-snmp/net-snmp-config.h>
#include <net-snmp/types.h>
#include <net-snmp/library/snmpTCPDomain.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_DMALLOC_H
#include <dmalloc.h>
#endif
#include <net-snmp/types.h>
#include <net-snmp/output_api.h>
#include <net-snmp/library/snmpIPv4BaseDomain.h>
#include <net-snmp/library/snmpSocketBaseDomain.h>
#include <net-snmp/library/snmpTCPBaseDomain.h>
#include <net-snmp/library/tools.h>
#ifndef NETSNMP_NO_SYSTEMD
#include <net-snmp/library/sd-daemon.h>
#endif
/*
* needs to be in sync with the definitions in snmplib/snmpUDPDomain.c
* and perl/agent/agent.xs
*/
typedef netsnmp_indexed_addr_pair 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, const void *data, int len)
{
return netsnmp_ipv4_fmtaddr("TCP", t, data, len);
}
static int
netsnmp_tcp_accept(netsnmp_transport *t)
{
struct sockaddr *farend = NULL;
netsnmp_udp_addr_pair *addr_pair = NULL;
int newsock = -1;
socklen_t farendlen;
addr_pair = malloc(sizeof(*addr_pair));
if (addr_pair == NULL) {
/*
* Indicate that the acceptance of this socket failed.
*/
DEBUGMSGTL(("netsnmp_tcp", "accept: malloc failed\n"));
return -1;
}
memset(addr_pair, 0, sizeof *addr_pair);
farend = &addr_pair->remote_addr.sa;
farendlen = sizeof(addr_pair->remote_addr.sa);
if (t != NULL && t->sock >= 0) {
newsock = (int) accept(t->sock, farend, &farendlen);
if (newsock < 0) {
DEBUGMSGTL(("netsnmp_tcp", "accept failed rc %d errno %d \"%s\"\n",
newsock, errno, strerror(errno)));
free(addr_pair);
return newsock;
}
if (t->data != NULL) {
free(t->data);
}
t->data = addr_pair;
t->data_length = sizeof(netsnmp_udp_addr_pair);
DEBUGIF("netsnmp_tcp") {
char *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.
*/
if (netsnmp_set_non_blocking_mode(newsock, FALSE) < 0)
DEBUGMSGTL(("netsnmp_tcp", "couldn't f_getfl of fd %d\n",
newsock));
/*
* 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(addr_pair);
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(const struct sockaddr_in *addr, int local)
{
netsnmp_transport *t = NULL;
netsnmp_udp_addr_pair *addr_pair = NULL;
int rc = 0;
int socket_initialized = 0;
#ifdef NETSNMP_NO_LISTEN_SUPPORT
if (local)
return NULL;
#endif /* NETSNMP_NO_LISTEN_SUPPORT */
if (addr == NULL || addr->sin_family != AF_INET) {
return NULL;
}
t = SNMP_MALLOC_TYPEDEF(netsnmp_transport);
if (t == NULL) {
return NULL;
}
addr_pair = (netsnmp_udp_addr_pair *)malloc(sizeof(netsnmp_udp_addr_pair));
if (addr_pair == NULL) {
netsnmp_transport_free(t);
return NULL;
}
memset(addr_pair, 0, sizeof *addr_pair);
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]);
#ifndef NETSNMP_NO_SYSTEMD
/*
* Maybe the socket was already provided by systemd...
*/
if (local) {
t->sock = netsnmp_sd_find_inet_socket(PF_INET, SOCK_STREAM, 1,
ntohs(addr->sin_port));
if (t->sock >= 0)
socket_initialized = 1;
}
#endif
if (!socket_initialized)
t->sock = (int) socket(PF_INET, SOCK_STREAM, 0);
if (t->sock < 0) {
netsnmp_transport_free(t);
return NULL;
}
t->flags = NETSNMP_TRANSPORT_FLAG_STREAM;
if (local) {
#ifndef NETSNMP_NO_LISTEN_SUPPORT
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_length = sizeof(*addr);
t->local = netsnmp_memdup(addr, sizeof(*addr));
if (!t->local) {
netsnmp_socketbase_close(t);
netsnmp_transport_free(t);
return NULL;
}
/*
* We should set SO_REUSEADDR too.
*/
setsockopt(t->sock, SOL_SOCKET, SO_REUSEADDR, (void *)&opt,
sizeof(opt));
if (!socket_initialized) {
rc = bind(t->sock, (const struct sockaddr *)addr, sizeof(*addr));
if (rc != 0) {
netsnmp_socketbase_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 non-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.
*/
netsnmp_set_non_blocking_mode(t->sock, TRUE);
/*
* Now sit here and wait for connections to arrive.
*/
if (!socket_initialized) {
rc = listen(t->sock, NETSNMP_STREAM_QUEUE_LEN);
if (rc != 0) {
netsnmp_socketbase_close(t);
netsnmp_transport_free(t);
return NULL;
}
}
/*
* no buffer size on listen socket - doesn't make sense
*/
#else /* NETSNMP_NO_LISTEN_SUPPORT */
return NULL;
#endif /* NETSNMP_NO_LISTEN_SUPPORT */
} else {
t->remote_length = sizeof(*addr);
t->remote = netsnmp_memdup(addr, sizeof(*addr));
if (!t->remote) {
netsnmp_socketbase_close(t);
netsnmp_transport_free(t);
return NULL;
}
/*
* 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, (const struct sockaddr *)addr, sizeof(*addr));
if (rc < 0) {
netsnmp_socketbase_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 = SNMP_MAX_PACKET_LEN;
t->f_recv = netsnmp_tcpbase_recv;
t->f_send = netsnmp_tcpbase_send;
t->f_close = netsnmp_socketbase_close;
t->f_accept = netsnmp_tcp_accept;
t->f_fmtaddr = netsnmp_tcp_fmtaddr;
t->f_get_taddr = netsnmp_ipv4_get_taddr;
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 void *o, size_t o_len, int local)
{
struct sockaddr_in sin;
if (netsnmp_ipv4_ostring_to_sockaddr(&sin, o, o_len))
return netsnmp_tcp_transport(&sin, 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);
}