trans_udp.c revision 312516
1193326Sed/* 2193326Sed * Copyright (c) 2003 3193326Sed * Fraunhofer Institute for Open Communication Systems (FhG Fokus). 4193326Sed * All rights reserved. 5193326Sed * 6193326Sed * Author: Harti Brandt <harti@freebsd.org> 7193326Sed * 8193326Sed * Redistribution and use in source and binary forms, with or without 9193326Sed * modification, are permitted provided that the following conditions 10198092Srdivacky * are met: 11193326Sed * 1. Redistributions of source code must retain the above copyright 12193326Sed * notice, this list of conditions and the following disclaimer. 13193326Sed * 2. Redistributions in binary form must reproduce the above copyright 14193326Sed * notice, this list of conditions and the following disclaimer in the 15249423Sdim * documentation and/or other materials provided with the distribution. 16206084Srdivacky * 17249423Sdim * THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND 18206084Srdivacky * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19234353Sdim * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20193326Sed * ARE DISCLAIMED. IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE 21249423Sdim * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22193326Sed * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23193326Sed * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24193326Sed * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25263508Sdim * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26249423Sdim * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27249423Sdim * SUCH DAMAGE. 28249423Sdim * 29193326Sed * $Begemot: bsnmp/snmpd/trans_udp.c,v 1.5 2005/10/04 08:46:56 brandt_h Exp $ 30193326Sed * 31193326Sed * UDP transport 32251662Sdim */ 33251662Sdim#include <sys/types.h> 34251662Sdim#include <sys/queue.h> 35251662Sdim#include <sys/ucred.h> 36251662Sdim 37224145Sdim#include <stdbool.h> 38193326Sed#include <stdlib.h> 39193326Sed#include <syslog.h> 40193326Sed#include <string.h> 41198092Srdivacky#include <errno.h> 42198092Srdivacky#include <unistd.h> 43193326Sed 44193326Sed#include <netinet/in.h> 45202379Srdivacky#include <arpa/inet.h> 46202379Srdivacky 47202379Srdivacky#include "snmpmod.h" 48202379Srdivacky#include "snmpd.h" 49193326Sed#include "trans_udp.h" 50193326Sed#include "tree.h" 51224145Sdim#include "oid.h" 52224145Sdim 53226633Sdimstatic int udp_start(void); 54234353Sdimstatic int udp_stop(int); 55221345Sdimstatic void udp_close_port(struct tport *); 56221345Sdimstatic int udp_init_port(struct tport *); 57221345Sdimstatic ssize_t udp_send(struct tport *, const u_char *, size_t, 58221345Sdim const struct sockaddr *, size_t); 59221345Sdimstatic ssize_t udp_recv(struct tport *, struct port_input *); 60221345Sdim 61221345Sdim/* exported */ 62221345Sdimconst struct transport_def udp_trans = { 63221345Sdim "udp", 64249423Sdim OIDX_begemotSnmpdTransUdp, 65221345Sdim udp_start, 66221345Sdim udp_stop, 67221345Sdim udp_close_port, 68221345Sdim udp_init_port, 69221345Sdim udp_send, 70221345Sdim udp_recv 71249423Sdim}; 72221345Sdimstatic struct transport *my_trans; 73221345Sdim 74221345Sdimstatic int 75221345Sdimudp_start(void) 76210299Sed{ 77221345Sdim return (trans_register(&udp_trans, &my_trans)); 78221345Sdim} 79221345Sdim 80224145Sdimstatic int 81221345Sdimudp_stop(int force __unused) 82221345Sdim{ 83193326Sed if (my_trans != NULL) 84193326Sed if (trans_unregister(my_trans) != 0) 85193326Sed return (SNMP_ERR_GENERR); 86193326Sed return (SNMP_ERR_NOERROR); 87224145Sdim} 88224145Sdim 89198092Srdivacky/* 90193326Sed * A UDP port is ready 91203955Srdivacky */ 92193326Sedstatic void 93198092Srdivackyudp_input(int fd __unused, void *udata) 94193326Sed{ 95198092Srdivacky struct udp_port *p = udata; 96198092Srdivacky 97224145Sdim p->input.peerlen = sizeof(p->ret); 98198092Srdivacky snmpd_input(&p->input, &p->tport); 99224145Sdim} 100224145Sdim 101224145Sdim/* 102224145Sdim * Create a UDP socket and bind it to the given port 103224145Sdim */ 104224145Sdimstatic int 105224145Sdimudp_init_port(struct tport *tp) 106193326Sed{ 107193326Sed struct udp_port *p = (struct udp_port *)tp; 108224145Sdim struct sockaddr_in addr; 109224145Sdim u_int32_t ip; 110224145Sdim const int on = 1; 111224145Sdim 112224145Sdim if ((p->input.fd = socket(PF_INET, SOCK_DGRAM, 0)) < 0) { 113224145Sdim syslog(LOG_ERR, "creating UDP socket: %m"); 114224145Sdim return (SNMP_ERR_RES_UNAVAIL); 115224145Sdim } 116224145Sdim ip = (p->addr[0] << 24) | (p->addr[1] << 16) | (p->addr[2] << 8) | 117224145Sdim p->addr[3]; 118224145Sdim memset(&addr, 0, sizeof(addr)); 119224145Sdim addr.sin_addr.s_addr = htonl(ip); 120224145Sdim addr.sin_port = htons(p->port); 121224145Sdim addr.sin_family = AF_INET; 122224145Sdim addr.sin_len = sizeof(addr); 123224145Sdim if (addr.sin_addr.s_addr == INADDR_ANY) { 124224145Sdim if (setsockopt(p->input.fd, IPPROTO_IP, IP_RECVDSTADDR, &on, 125224145Sdim sizeof(on)) == -1) { 126224145Sdim syslog(LOG_ERR, "setsockopt(IP_RECVDSTADDR): %m"); 127224145Sdim close(p->input.fd); 128224145Sdim p->input.fd = -1; 129224145Sdim return (SNMP_ERR_GENERR); 130224145Sdim } 131224145Sdim p->recvdstaddr = true; 132224145Sdim } 133224145Sdim if (bind(p->input.fd, (struct sockaddr *)&addr, sizeof(addr))) { 134224145Sdim if (errno == EADDRNOTAVAIL) { 135224145Sdim close(p->input.fd); 136224145Sdim p->input.fd = -1; 137224145Sdim return (SNMP_ERR_INCONS_NAME); 138224145Sdim } 139224145Sdim syslog(LOG_ERR, "bind: %s:%u %m", inet_ntoa(addr.sin_addr), 140224145Sdim p->port); 141224145Sdim close(p->input.fd); 142224145Sdim p->input.fd = -1; 143224145Sdim return (SNMP_ERR_GENERR); 144224145Sdim } 145224145Sdim if ((p->input.id = fd_select(p->input.fd, udp_input, 146224145Sdim p, NULL)) == NULL) { 147224145Sdim close(p->input.fd); 148224145Sdim p->input.fd = -1; 149224145Sdim return (SNMP_ERR_GENERR); 150224145Sdim } 151224145Sdim return (SNMP_ERR_NOERROR); 152224145Sdim} 153193326Sed 154193326Sed/* 155224145Sdim * Create a new SNMP Port object and start it, if we are not 156224145Sdim * in initialization mode. The arguments are in host byte order. 157224145Sdim */ 158224145Sdimstatic int 159224145Sdimudp_open_port(u_int8_t *addr, u_int32_t udp_port, struct udp_port **pp) 160224145Sdim{ 161224145Sdim struct udp_port *port; 162224145Sdim int err; 163224145Sdim 164224145Sdim if (udp_port > 0xffff) 165224145Sdim return (SNMP_ERR_NO_CREATION); 166224145Sdim if ((port = malloc(sizeof(*port))) == NULL) 167224145Sdim return (SNMP_ERR_GENERR); 168224145Sdim memset(port, 0, sizeof(*port)); 169224145Sdim 170198092Srdivacky /* initialize common part */ 171224145Sdim port->tport.index.len = 5; 172224145Sdim port->tport.index.subs[0] = addr[0]; 173224145Sdim port->tport.index.subs[1] = addr[1]; 174224145Sdim port->tport.index.subs[2] = addr[2]; 175224145Sdim port->tport.index.subs[3] = addr[3]; 176198092Srdivacky port->tport.index.subs[4] = udp_port; 177193326Sed 178224145Sdim port->addr[0] = addr[0]; 179224145Sdim port->addr[1] = addr[1]; 180224145Sdim port->addr[2] = addr[2]; 181224145Sdim port->addr[3] = addr[3]; 182224145Sdim port->port = udp_port; 183224145Sdim 184224145Sdim port->input.fd = -1; 185224145Sdim port->input.id = NULL; 186224145Sdim port->input.stream = 0; 187224145Sdim port->input.cred = 0; 188193326Sed port->input.peer = (struct sockaddr *)&port->ret; 189193326Sed port->input.peerlen = sizeof(port->ret); 190224145Sdim 191224145Sdim trans_insert_port(my_trans, &port->tport); 192224145Sdim 193224145Sdim if (community != COMM_INITIALIZE && 194224145Sdim (err = udp_init_port(&port->tport)) != SNMP_ERR_NOERROR) { 195224145Sdim udp_close_port(&port->tport); 196224145Sdim return (err); 197224145Sdim } 198224145Sdim *pp = port; 199234353Sdim return (SNMP_ERR_NOERROR); 200234353Sdim} 201234353Sdim 202224145Sdim/* 203224145Sdim * Close an SNMP port 204224145Sdim */ 205224145Sdimstatic void 206224145Sdimudp_close_port(struct tport *tp) 207224145Sdim{ 208224145Sdim struct udp_port *port = (struct udp_port *)tp; 209224145Sdim 210224145Sdim snmpd_input_close(&port->input); 211224145Sdim trans_remove_port(tp); 212224145Sdim free(port); 213224145Sdim} 214224145Sdim 215224145Sdim/* 216224145Sdim * Send something 217224145Sdim */ 218224145Sdimstatic ssize_t 219224145Sdimudp_send(struct tport *tp, const u_char *buf, size_t len, 220224145Sdim const struct sockaddr *addr, size_t addrlen) 221224145Sdim{ 222224145Sdim struct udp_port *p = (struct udp_port *)tp; 223224145Sdim struct cmsghdr *cmsg; 224224145Sdim struct msghdr msg; 225224145Sdim char cbuf[CMSG_SPACE(sizeof(struct in_addr))]; 226224145Sdim struct iovec iov; 227224145Sdim 228224145Sdim iov.iov_base = __DECONST(void*, buf); 229224145Sdim iov.iov_len = len; 230224145Sdim 231224145Sdim msg.msg_flags = 0; 232224145Sdim msg.msg_iov = &iov; 233224145Sdim msg.msg_iovlen = 1; 234224145Sdim msg.msg_name = __DECONST(void *, addr); 235224145Sdim msg.msg_namelen = addrlen; 236224145Sdim 237224145Sdim if (p->recvdstaddr) { 238224145Sdim msg.msg_control = cbuf; 239224145Sdim msg.msg_controllen = sizeof(cbuf); 240224145Sdim 241224145Sdim cmsg = CMSG_FIRSTHDR(&msg); 242224145Sdim cmsg->cmsg_level = IPPROTO_IP; 243224145Sdim cmsg->cmsg_type = IP_SENDSRCADDR; 244224145Sdim cmsg->cmsg_len = CMSG_LEN(sizeof(struct in_addr)); 245224145Sdim memcpy(CMSG_DATA(cmsg), &p->dstaddr, sizeof(struct in_addr)); 246224145Sdim } else { 247224145Sdim msg.msg_control = NULL; 248224145Sdim msg.msg_controllen = 0; 249224145Sdim } 250193326Sed 251224145Sdim return (sendmsg(p->input.fd, &msg, 0)); 252193326Sed} 253224145Sdim 254224145Sdimstatic void 255224145Sdimcheck_priv_dgram(struct port_input *pi, struct sockcred *cred) 256224145Sdim{ 257224145Sdim 258224145Sdim /* process explicitly sends credentials */ 259224145Sdim if (cred) 260224145Sdim pi->priv = (cred->sc_euid == 0); 261224145Sdim else 262224145Sdim pi->priv = 0; 263263508Sdim} 264263508Sdim 265263508Sdim/* 266263508Sdim * Input from a datagram socket. 267263508Sdim * Each receive should return one datagram. 268193326Sed */ 269193326Sedstatic ssize_t 270224145Sdimudp_recv(struct tport *tp, struct port_input *pi) 271249423Sdim{ 272249423Sdim u_char embuf[1000]; 273249423Sdim char cbuf[CMSG_SPACE(SOCKCREDSIZE(CMGROUP_MAX)) + 274249423Sdim CMSG_SPACE(sizeof(struct in_addr))]; 275249423Sdim struct udp_port *p = (struct udp_port *)tp; 276249423Sdim struct msghdr msg; 277249423Sdim struct iovec iov[1]; 278249423Sdim ssize_t len; 279193326Sed struct cmsghdr *cmsg; 280198092Srdivacky struct sockcred *cred = NULL; 281193326Sed 282198092Srdivacky if (pi->buf == NULL) { 283193326Sed /* no buffer yet - allocate one */ 284198092Srdivacky if ((pi->buf = buf_alloc(0)) == NULL) { 285193326Sed /* ups - could not get buffer. Read away input 286198092Srdivacky * and drop it */ 287193326Sed (void)recvfrom(pi->fd, embuf, sizeof(embuf), 288198092Srdivacky 0, NULL, NULL); 289226633Sdim /* return error */ 290193326Sed return (-1); 291193326Sed } 292224145Sdim pi->buflen = buf_size(0); 293224145Sdim } 294224145Sdim 295198092Srdivacky /* try to get a message */ 296224145Sdim msg.msg_name = pi->peer; 297224145Sdim msg.msg_namelen = pi->peerlen; 298224145Sdim msg.msg_iov = iov; 299224145Sdim msg.msg_iovlen = 1; 300224145Sdim memset(cbuf, 0, sizeof(cbuf)); 301224145Sdim msg.msg_control = cbuf; 302224145Sdim msg.msg_controllen = sizeof(cbuf); 303224145Sdim msg.msg_flags = 0; 304224145Sdim 305224145Sdim iov[0].iov_base = pi->buf; 306224145Sdim iov[0].iov_len = pi->buflen; 307224145Sdim 308224145Sdim len = recvmsg(pi->fd, &msg, 0); 309224145Sdim 310224145Sdim if (len == -1 || len == 0) 311224145Sdim /* receive error */ 312193326Sed return (-1); 313193326Sed 314193326Sed if (msg.msg_flags & MSG_TRUNC) { 315193326Sed /* truncated - drop */ 316204643Srdivacky snmpd_stats.silentDrops++; 317193326Sed snmpd_stats.inTooLong++; 318221345Sdim return (-1); 319193326Sed } 320193326Sed 321224145Sdim pi->length = (size_t)len; 322193326Sed 323198092Srdivacky for (cmsg = CMSG_FIRSTHDR(&msg); cmsg != NULL; 324198092Srdivacky cmsg = CMSG_NXTHDR(&msg, cmsg)) { 325199990Srdivacky if (cmsg->cmsg_level == IPPROTO_IP && 326193326Sed cmsg->cmsg_type == IP_RECVDSTADDR) 327193326Sed memcpy(&p->dstaddr, CMSG_DATA(cmsg), 328224145Sdim sizeof(struct in_addr)); 329224145Sdim if (cmsg->cmsg_level == SOL_SOCKET && 330193326Sed cmsg->cmsg_type == SCM_CREDS) 331193326Sed cred = (struct sockcred *)CMSG_DATA(cmsg); 332193326Sed } 333224145Sdim 334224145Sdim if (pi->cred) 335198092Srdivacky check_priv_dgram(pi, cred); 336193326Sed 337193326Sed return (0); 338193326Sed} 339193326Sed 340193326Sed/* 341193326Sed * Port table 342193326Sed */ 343193326Sedint 344193326Sedop_snmp_port(struct snmp_context *ctx, struct snmp_value *value, 345193326Sed u_int sub, u_int iidx, enum snmp_op op) 346193326Sed{ 347193326Sed asn_subid_t which = value->var.subs[sub-1]; 348218893Sdim struct udp_port *p; 349218893Sdim u_int8_t addr[4]; 350198092Srdivacky u_int32_t port; 351198092Srdivacky 352224145Sdim switch (op) { 353224145Sdim 354224145Sdim case SNMP_OP_GETNEXT: 355198092Srdivacky if ((p = (struct udp_port *)trans_next_port(my_trans, 356226633Sdim &value->var, sub)) == NULL) 357249423Sdim return (SNMP_ERR_NOSUCHNAME); 358249423Sdim index_append(&value->var, sub, &p->tport.index); 359249423Sdim break; 360249423Sdim 361226633Sdim case SNMP_OP_GET: 362193326Sed if ((p = (struct udp_port *)trans_find_port(my_trans, 363193326Sed &value->var, sub)) == NULL) 364193326Sed return (SNMP_ERR_NOSUCHNAME); 365224145Sdim break; 366249423Sdim 367249423Sdim case SNMP_OP_SET: 368224145Sdim p = (struct udp_port *)trans_find_port(my_trans, 369198092Srdivacky &value->var, sub); 370224145Sdim ctx->scratch->int1 = (p != NULL); 371198092Srdivacky 372224145Sdim if (which != LEAF_begemotSnmpdPortStatus) 373224145Sdim abort(); 374198092Srdivacky if (!TRUTH_OK(value->v.integer)) 375193326Sed return (SNMP_ERR_WRONG_VALUE); 376193326Sed 377224145Sdim ctx->scratch->int2 = TRUTH_GET(value->v.integer); 378224145Sdim 379249423Sdim if (ctx->scratch->int2) { 380249423Sdim /* open an SNMP port */ 381249423Sdim if (p != NULL) 382249423Sdim /* already open - do nothing */ 383249423Sdim return (SNMP_ERR_NOERROR); 384249423Sdim 385249423Sdim if (index_decode(&value->var, sub, iidx, addr, &port)) 386249423Sdim return (SNMP_ERR_NO_CREATION); 387249423Sdim return (udp_open_port(addr, port, &p)); 388249423Sdim 389249423Sdim } else { 390201361Srdivacky /* close SNMP port - do in commit */ 391201361Srdivacky } 392234353Sdim return (SNMP_ERR_NOERROR); 393234353Sdim 394234353Sdim case SNMP_OP_ROLLBACK: 395234353Sdim p = (struct udp_port *)trans_find_port(my_trans, 396221345Sdim &value->var, sub); 397193326Sed if (ctx->scratch->int1 == 0) { 398193326Sed /* did not exist */ 399193326Sed if (ctx->scratch->int2 == 1) { 400251662Sdim /* created */ 401251662Sdim if (p != NULL) 402193326Sed udp_close_port(&p->tport); 403224145Sdim } 404224145Sdim } 405224145Sdim return (SNMP_ERR_NOERROR); 406193326Sed 407193326Sed case SNMP_OP_COMMIT: 408193326Sed p = (struct udp_port *)trans_find_port(my_trans, 409224145Sdim &value->var, sub); 410224145Sdim if (ctx->scratch->int1 == 1) { 411224145Sdim /* did exist */ 412221345Sdim if (ctx->scratch->int2 == 0) { 413224145Sdim /* delete */ 414224145Sdim if (p != NULL) 415193326Sed udp_close_port(&p->tport); 416193326Sed } 417224145Sdim } 418224145Sdim return (SNMP_ERR_NOERROR); 419224145Sdim 420224145Sdim default: 421224145Sdim abort(); 422221345Sdim } 423224145Sdim 424224145Sdim /* 425193326Sed * Come here to fetch the value 426198092Srdivacky */ 427193326Sed switch (which) { 428224145Sdim 429224145Sdim case LEAF_begemotSnmpdPortStatus: 430193326Sed value->v.integer = 1; 431193326Sed break; 432193326Sed 433224145Sdim default: 434224145Sdim abort(); 435193326Sed } 436193326Sed 437224145Sdim return (SNMP_ERR_NOERROR); 438224145Sdim} 439193326Sed