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TP-Link_Archer-XR500v/EN7526G_3.18Kernel_SDK/apps/public/net-snmp-5.3.1/snmplib/snmpUnixDomain.c
2024-07-22 01:58:46 -03:00

649 lines
18 KiB
C
Executable File

#include <net-snmp/net-snmp-config.h>
#include <stdio.h>
#include <sys/types.h>
#include <ctype.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_SYS_UN_H
#include <sys/un.h>
#endif
#if HAVE_DMALLOC_H
#include <dmalloc.h>
#endif
#include <net-snmp/types.h>
#include <net-snmp/output_api.h>
#include <net-snmp/config_api.h>
#include <net-snmp/library/snmp_transport.h>
#include <net-snmp/library/snmpUDPDomain.h>
#include <net-snmp/library/snmpUnixDomain.h>
#ifndef NETSNMP_STREAM_QUEUE_LEN
#define NETSNMP_STREAM_QUEUE_LEN 5
#endif
#ifndef SUN_LEN
/*
* Evaluate to actual length of the `sockaddr_un' structure.
*/
#define SUN_LEN(ptr) ((size_t) (((struct sockaddr_un *) 0)->sun_path) \
+ strlen ((ptr)->sun_path))
#endif
oid netsnmp_UnixDomain[] = { TRANSPORT_DOMAIN_LOCAL };
static netsnmp_tdomain unixDomain;
/*
* This is the structure we use to hold transport-specific data.
*/
typedef struct _sockaddr_un_pair {
int local;
struct sockaddr_un server;
struct sockaddr_un client;
} sockaddr_un_pair;
/*
* Return a string representing the address in data, or else the "far end"
* address if data is NULL.
*/
static char *
netsnmp_unix_fmtaddr(netsnmp_transport *t, void *data, int len)
{
struct sockaddr_un *to = NULL;
if (data != NULL) {
to = (struct sockaddr_un *) data;
} else if (t != NULL && t->data != NULL) {
to = &(((sockaddr_un_pair *) t->data)->server);
len = SUN_LEN(to);
}
if (to == NULL) {
/*
* "Local IPC" is the Posix.1g term for Unix domain protocols,
* according to W. R. Stevens, ``Unix Network Programming Volume I
* Second Edition'', p. 374.
*/
return strdup("Local IPC: unknown");
} else if (to->sun_path[0] == 0) {
/*
* This is an abstract name. We could render it as hex or something
* but let's not worry about that for now.
*/
return strdup("Local IPC: abstract");
} else {
char *tmp = (char *) malloc(16 + len);
if (tmp != NULL) {
sprintf(tmp, "Local IPC: %s", to->sun_path);
}
return 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_unix_recv(netsnmp_transport *t, void *buf, int size,
void **opaque, int *olength)
{
int rc = -1;
socklen_t tolen = sizeof(struct sockaddr_un);
struct sockaddr *to;
if (t != NULL && t->sock >= 0) {
to = (struct sockaddr *) malloc(sizeof(struct sockaddr_un));
if (to == NULL) {
*opaque = NULL;
*olength = 0;
return -1;
} else {
memset(to, 0, tolen);
}
if(getsockname(t->sock, to, &tolen) != 0){
free(to);
*opaque = NULL;
*olength = 0;
return -1;
};
while (rc < 0) {
rc = recv(t->sock, buf, size, 0);
if (rc < 0 && errno != EINTR) {
DEBUGMSGTL(("netsnmp_unix", "recv fd %d err %d (\"%s\")\n",
t->sock, errno, strerror(errno)));
return rc;
}
*opaque = (void*)to;
*olength = sizeof(struct sockaddr_un);
}
DEBUGMSGTL(("netsnmp_unix", "recv fd %d got %d bytes\n", t->sock, rc));
}
return rc;
}
static int
netsnmp_unix_send(netsnmp_transport *t, void *buf, int size,
void **opaque, int *olength)
{
int rc = -1;
if (t != NULL && t->sock >= 0) {
DEBUGMSGTL(("netsnmp_unix", "send %d bytes to %p on fd %d\n",
size, buf, t->sock));
while (rc < 0) {
rc = send(t->sock, buf, size, 0);
if (rc < 0 && errno != EINTR) {
break;
}
}
}
return rc;
}
static int
netsnmp_unix_close(netsnmp_transport *t)
{
int rc = 0;
sockaddr_un_pair *sup = (sockaddr_un_pair *) t->data;
if (t->sock >= 0) {
#ifndef HAVE_CLOSESOCKET
rc = close(t->sock);
#else
rc = closesocket(t->sock);
#endif
t->sock = -1;
if (sup != NULL) {
if (sup->local) {
if (sup->server.sun_path[0] != 0) {
DEBUGMSGTL(("netsnmp_unix", "close: server unlink(\"%s\")\n",
sup->server.sun_path));
unlink(sup->server.sun_path);
}
} else {
if (sup->client.sun_path[0] != 0) {
DEBUGMSGTL(("netsnmp_unix", "close: client unlink(\"%s\")\n",
sup->client.sun_path));
unlink(sup->client.sun_path);
}
}
}
return rc;
} else {
return -1;
}
}
static int
netsnmp_unix_accept(netsnmp_transport *t)
{
struct sockaddr *farend = NULL;
int newsock = -1;
socklen_t farendlen = sizeof(struct sockaddr_un);
farend = (struct sockaddr *) malloc(farendlen);
if (farend == NULL) {
/*
* Indicate that the acceptance of this socket failed.
*/
DEBUGMSGTL(("netsnmp_unix", "accept: malloc failed\n"));
return -1;
}
memset(farend, 0, farendlen);
if (t != NULL && t->sock >= 0) {
newsock = accept(t->sock, farend, &farendlen);
if (newsock < 0) {
DEBUGMSGTL(("netsnmp_unix","accept failed rc %d errno %d \"%s\"\n",
newsock, errno, strerror(errno)));
free(farend);
return newsock;
}
if (t->data != NULL) {
free(t->data);
}
DEBUGMSGTL(("netsnmp_unix", "accept succeeded (farend %p len %d)\n",
farend, farendlen));
t->data = farend;
t->data_length = sizeof(struct sockaddr_un);
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 Unix-domain 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 (and we make up a temporary name for
* the local end of the connection).
*/
netsnmp_transport *
netsnmp_unix_transport(struct sockaddr_un *addr, int local)
{
netsnmp_transport *t = NULL;
sockaddr_un_pair *sup = NULL;
int rc = 0;
char *string = NULL;
if (addr == NULL || addr->sun_family != AF_UNIX) {
return NULL;
}
t = (netsnmp_transport *) malloc(sizeof(netsnmp_transport));
if (t == NULL) {
return NULL;
}
string = netsnmp_unix_fmtaddr(NULL, (void *)addr,
sizeof(struct sockaddr_un));
DEBUGMSGTL(("netsnmp_unix", "open %s %s\n", local ? "local" : "remote",
string));
free(string);
memset(t, 0, sizeof(netsnmp_transport));
t->domain = netsnmp_UnixDomain;
t->domain_length =
sizeof(netsnmp_UnixDomain) / sizeof(netsnmp_UnixDomain[0]);
t->data = malloc(sizeof(sockaddr_un_pair));
if (t->data == NULL) {
netsnmp_transport_free(t);
return NULL;
}
memset(t->data, 0, sizeof(sockaddr_un_pair));
t->data_length = sizeof(sockaddr_un_pair);
sup = (sockaddr_un_pair *) t->data;
t->sock = socket(PF_UNIX, SOCK_STREAM, 0);
if (t->sock < 0) {
netsnmp_transport_free(t);
return NULL;
}
t->flags = NETSNMP_TRANSPORT_FLAG_STREAM;
if (local) {
t->local = malloc(strlen(addr->sun_path));
if (t->local == NULL) {
netsnmp_transport_free(t);
return NULL;
}
memcpy(t->local, addr->sun_path, strlen(addr->sun_path));
t->local_length = strlen(addr->sun_path);
/*
* This session is inteneded as a server, so we must bind to the given
* path (unlinking it first, to avoid errors).
*/
t->flags |= NETSNMP_TRANSPORT_FLAG_LISTEN;
unlink(addr->sun_path);
rc = bind(t->sock, (struct sockaddr *) addr, SUN_LEN(addr));
if (rc != 0) {
DEBUGMSGTL(("netsnmp_unix_transport",
"couldn't bind \"%s\", errno %d (%s)\n",
addr->sun_path, errno, strerror(errno)));
netsnmp_unix_close(t);
netsnmp_transport_free(t);
return NULL;
}
/*
* Save the address in the transport-specific data pointer for later
* use by netsnmp_unix_close.
*/
sup->server.sun_family = AF_UNIX;
strcpy(sup->server.sun_path, addr->sun_path);
sup->local = 1;
/*
* Now sit here and listen for connections to arrive.
*/
rc = listen(t->sock, NETSNMP_STREAM_QUEUE_LEN);
if (rc != 0) {
DEBUGMSGTL(("netsnmp_unix_transport",
"couldn't listen to \"%s\", errno %d (%s)\n",
addr->sun_path, errno, strerror(errno)));
netsnmp_unix_close(t);
netsnmp_transport_free(t);
return NULL;
}
} else {
t->remote = malloc(strlen(addr->sun_path));
if (t->remote == NULL) {
netsnmp_transport_free(t);
return NULL;
}
memcpy(t->remote, addr->sun_path, strlen(addr->sun_path));
t->remote_length = strlen(addr->sun_path);
rc = connect(t->sock, (struct sockaddr *) addr,
sizeof(struct sockaddr_un));
if (rc != 0) {
DEBUGMSGTL(("netsnmp_unix_transport",
"couldn't connect to \"%s\", errno %d (%s)\n",
addr->sun_path, errno, strerror(errno)));
netsnmp_unix_close(t);
netsnmp_transport_free(t);
return NULL;
}
/*
* Save the remote address in the transport-specific data pointer for
* later use by netsnmp_unix_send.
*/
sup->server.sun_family = AF_UNIX;
strcpy(sup->server.sun_path, addr->sun_path);
sup->local = 0;
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_unix_recv;
t->f_send = netsnmp_unix_send;
t->f_close = netsnmp_unix_close;
t->f_accept = netsnmp_unix_accept;
t->f_fmtaddr = netsnmp_unix_fmtaddr;
return t;
}
netsnmp_transport *
netsnmp_unix_create_tstring(const char *string, int local)
{
struct sockaddr_un addr;
if ((string != NULL) && (strlen(string) < sizeof(addr.sun_path))) {
addr.sun_family = AF_UNIX;
memset(addr.sun_path, 0, sizeof(addr.sun_path));
strncpy(addr.sun_path, string, sizeof(addr.sun_path) - 1);
return netsnmp_unix_transport(&addr, local);
} else {
if (string != NULL) {
snmp_log(LOG_ERR, "Path too long for Unix domain transport\n");
}
return NULL;
}
}
netsnmp_transport *
netsnmp_unix_create_ostring(const u_char * o, size_t o_len, int local)
{
struct sockaddr_un addr;
if (o_len > 0 && o_len < (sizeof(addr.sun_path) - 1)) {
addr.sun_family = AF_UNIX;
memset(addr.sun_path, 0, sizeof(addr.sun_path));
strncpy(addr.sun_path, o, o_len);
return netsnmp_unix_transport(&addr, local);
} else {
if (o_len > 0) {
snmp_log(LOG_ERR, "Path too long for Unix domain transport\n");
}
}
return NULL;
}
void
netsnmp_unix_ctor(void)
{
unixDomain.name = netsnmp_UnixDomain;
unixDomain.name_length = sizeof(netsnmp_UnixDomain) / sizeof(oid);
unixDomain.prefix = calloc(2, sizeof(char *));
unixDomain.prefix[0] = "unix";
unixDomain.f_create_from_tstring = netsnmp_unix_create_tstring;
unixDomain.f_create_from_ostring = netsnmp_unix_create_ostring;
netsnmp_tdomain_register(&unixDomain);
}
#if !defined(DISABLE_SNMPV1) || !defined(DISABLE_SNMPV2C)
/* support for SNMPv1 and SNMPv2c on unix domain*/
#define EXAMPLE_COMMUNITY "COMMUNITY"
typedef struct _com2SecUnixEntry {
char community[VACMSTRINGLEN];
char sockpath[sizeof(struct sockaddr_un)];
unsigned long pathlen;
char secName[VACMSTRINGLEN];
char contextName[VACMSTRINGLEN];
struct _com2SecUnixEntry *next;
} com2SecUnixEntry;
com2SecUnixEntry *com2SecUnixList = NULL, *com2SecUnixListLast = NULL;
int
netsnmp_unix_getSecName(void *opaque, int olength,
const char *community,
size_t community_len,
char **secName, char **contextName)
{
com2SecUnixEntry *c;
struct sockaddr_un *to = (struct sockaddr_un *) opaque;
char *ztcommunity = NULL;
if (secName != NULL) {
*secName = NULL; /* Haven't found anything yet */
}
/*
* Special case if there are NO entries (as opposed to no MATCHING
* entries).
*/
if (com2SecUnixList == NULL) {
DEBUGMSGTL(("netsnmp_unix_getSecName", "no com2sec entries\n"));
return 0;
}
/*
* If there is no unix socket path, then there can be no valid security
* name.
*/
if (opaque == NULL || olength != sizeof(struct sockaddr_un) ||
to->sun_family != AF_UNIX) {
DEBUGMSGTL(("netsnmp_unix_getSecName",
"no unix destine address in PDU?\n"));
return 1;
}
DEBUGIF("netsnmp_unix_getSecName") {
ztcommunity = (char *)malloc(community_len + 1);
if (ztcommunity != NULL) {
memcpy(ztcommunity, community, community_len);
ztcommunity[community_len] = '\0';
}
DEBUGMSGTL(("netsnmp_unix_getSecName", "resolve <\"%s\">\n",
ztcommunity ? ztcommunity : "<malloc error>"));
}
for (c = com2SecUnixList; c != NULL; c = c->next) {
DEBUGMSGTL(("netsnmp_unix_getSecName","compare <\"%s\",to socket %s>",
c->community, c->sockpath ));
if ((community_len == strlen(c->community)) &&
(memcmp(community, c->community, community_len) == 0) &&
/* compare sockpath, if pathlen == 0, always match */
(strlen(to->sun_path) == c->pathlen || c->pathlen == 0) &&
(memcmp(to->sun_path, c->sockpath, c->pathlen) == 0)
) {
DEBUGMSG(("netsnmp_unix_getSecName", "... SUCCESS\n"));
if (secName != NULL) {
*secName = c->secName;
*contextName = c->contextName;
}
break;
}
DEBUGMSG(("netsnmp_unix_getSecName", "... nope\n"));
}
if (ztcommunity != NULL) {
free(ztcommunity);
}
return 1;
}
void
netsnmp_unix_parse_security(const char *token, char *param)
{
char secName[VACMSTRINGLEN + 1], community[VACMSTRINGLEN + 1];
char contextName[VACMSTRINGLEN + 1];
char sockpath[sizeof(struct sockaddr_un) + 1];
com2SecUnixEntry *e = NULL;
param = copy_nword(param, secName, VACMSTRINGLEN);
if (strcmp(secName, "-Cn") == 0) {
if (!secName) {
config_perror("missing CONTEXT_NAME parameter");
return;
}
param = copy_nword( param, contextName, sizeof(contextName));
param = copy_nword( param, secName, sizeof(secName));
} else {
contextName[0] = '\0';
}
if (secName[0] == '\0') {
config_perror("missing NAME parameter");
return;
} else if (strlen(secName) > (VACMSTRINGLEN - 1)) {
config_perror("security name too long");
return;
}
param = copy_nword(param, sockpath, sizeof(struct sockaddr_un) - 1);
if (sockpath[0] == '\0') {
config_perror("missing SOCKPATH parameter");
return;
} else if (strlen(sockpath) > (sizeof(struct sockaddr_un) - 1)) {
config_perror("sockpath too long");
return;
}
/* if sockpath == "default", set pathlen=0*/
if(strcmp(sockpath, "default") == 0){
sockpath[0] = 0;
}
param = copy_nword(param, community, VACMSTRINGLEN);
if (community[0] == '\0') {
config_perror("missing COMMUNITY parameter\n");
return;
} else if (strncmp
(community, EXAMPLE_COMMUNITY, strlen(EXAMPLE_COMMUNITY))
== 0) {
config_perror("example config COMMUNITY not properly configured");
return;
} else if (strlen(community) > (VACMSTRINGLEN - 1)) {
config_perror("community name too long");
return;
}
e = (com2SecUnixEntry *) malloc(sizeof(com2SecUnixEntry));
if (e == NULL) {
config_perror("memory error");
return;
}
DEBUGMSGTL(("netsnmp_unix_parse_security",
"<\"%s\"> => \"%s\"\n", community, secName));
strcpy(e->secName, secName);
strcpy(e->contextName, contextName);
strcpy(e->community, community);
strcpy(e->sockpath, sockpath);
e->pathlen = strlen(sockpath);
e->next = NULL;
if (com2SecUnixListLast != NULL) {
com2SecUnixListLast->next = e;
com2SecUnixListLast = e;
} else {
com2SecUnixListLast = com2SecUnixList = e;
}
}
void
netsnmp_unix_com2SecList_free(void)
{
com2SecUnixEntry *e = com2SecUnixList;
while (e != NULL) {
com2SecUnixEntry *tmp = e;
e = e->next;
free(tmp);
}
com2SecUnixList = com2SecUnixListLast = NULL;
}
#endif /* support for community based SNMP */
void
netsnmp_unix_agent_config_tokens_register(void)
{
#if !defined(DISABLE_SNMPV1) || !defined(DISABLE_SNMPV2C)
register_app_config_handler("com2secunix", netsnmp_unix_parse_security,
netsnmp_unix_com2SecList_free,
"[-Cn CONTEXT] secName sockpath community");
#endif /* support for community based SNMP */
}