/*
* Returns the local/remote IP-address/hostname of socket as a string.
* The returned string must be freed.
*/
static char *
get_socket_address(int sock, int remote, int flags)
{
struct sockaddr_storage addr;
socklen_t addrlen;
char ntop[NI_MAXHOST];
int r;
/* Get IP address of client. */
addrlen = sizeof(addr);
memset(&addr, 0, sizeof(addr));
if (remote) {
if (getpeername(sock, (struct sockaddr *)&addr, &addrlen)
< 0)
return NULL;
} else {
if (getsockname(sock, (struct sockaddr *)&addr, &addrlen)
< 0)
return NULL;
}
/* Work around Linux IPv6 weirdness */
if (addr.ss_family == AF_INET6) {
addrlen = sizeof(struct sockaddr_in6);
ipv64_normalise_mapped(&addr, &addrlen);
}
switch (addr.ss_family) {
case AF_INET:
case AF_INET6:
/* Get the address in ascii. */
if ((r = getnameinfo((struct sockaddr *)&addr, addrlen, ntop,
sizeof(ntop), NULL, 0, flags)) != 0) {
error("get_socket_address: getnameinfo %d failed: %s",
flags, ssh_gai_strerror(r));
return NULL;
}
return xstrdup(ntop);
case AF_UNIX:
/* Get the Unix domain socket path. */
return xstrdup(((struct sockaddr_un *)&addr)->sun_path);
default:
/* We can't look up remote Unix domain sockets. */
return NULL;
}
}
void
record_failed_login(const char *username, const char *hostname,
const char *ttyn)
{
int fd;
struct utmp ut;
struct sockaddr_storage from;
socklen_t fromlen = sizeof(from);
struct sockaddr_in *a4;
struct sockaddr_in6 *a6;
time_t t;
struct stat fst;
if (geteuid() != 0)
return;
if ((fd = open(_PATH_BTMP, O_WRONLY | O_APPEND)) < 0) {
debug("Unable to open the btmp file %s: %s", _PATH_BTMP,
strerror(errno));
return;
}
if (fstat(fd, &fst) < 0) {
logit("%s: fstat of %s failed: %s", __func__, _PATH_BTMP,
strerror(errno));
goto out;
}
if((fst.st_mode & (S_IXGRP | S_IRWXO)) || (fst.st_uid != 0)){
logit("Excess permission or bad ownership on file %s",
_PATH_BTMP);
goto out;
}
memset(&ut, 0, sizeof(ut));
/* strncpy because we don't necessarily want nul termination */
strncpy(ut.ut_user, username, sizeof(ut.ut_user));
strlcpy(ut.ut_line, "ssh:notty", sizeof(ut.ut_line));
time(&t);
ut.ut_time = t; /* ut_time is not always a time_t */
ut.ut_type = LOGIN_PROCESS;
ut.ut_pid = getpid();
/* strncpy because we don't necessarily want nul termination */
strncpy(ut.ut_host, hostname, sizeof(ut.ut_host));
if (packet_connection_is_on_socket() &&
getpeername(packet_get_connection_in(),
(struct sockaddr *)&from, &fromlen) == 0) {
ipv64_normalise_mapped(&from, &fromlen);
if (from.ss_family == AF_INET) {
a4 = (struct sockaddr_in *)&from;
memcpy(&ut.ut_addr, &(a4->sin_addr),
MIN_SIZEOF(ut.ut_addr, a4->sin_addr));
}
#ifdef HAVE_ADDR_V6_IN_UTMP
if (from.ss_family == AF_INET6) {
a6 = (struct sockaddr_in6 *)&from;
memcpy(&ut.ut_addr_v6, &(a6->sin6_addr),
MIN_SIZEOF(ut.ut_addr_v6, a6->sin6_addr));
}
#endif
}
if (atomicio(vwrite, fd, &ut, sizeof(ut)) != sizeof(ut))
error("Failed to write to %s: %s", _PATH_BTMP,
strerror(errno));
out:
close(fd);
}
static char *
get_remote_hostname(int sock, int use_dns)
{
struct sockaddr_storage from;
int i;
socklen_t fromlen;
struct addrinfo hints, *ai, *aitop;
char name[NI_MAXHOST], ntop[NI_MAXHOST], ntop2[NI_MAXHOST];
/* Get IP address of client. */
fromlen = sizeof(from);
memset(&from, 0, sizeof(from));
if (getpeername(sock, (struct sockaddr *)&from, &fromlen) < 0) {
debug("getpeername failed: %.100s", strerror(errno));
cleanup_exit(255);
}
if (from.ss_family == AF_INET)
check_ip_options(sock, ntop);
ipv64_normalise_mapped(&from, &fromlen);
if (from.ss_family == AF_INET6)
fromlen = sizeof(struct sockaddr_in6);
if (getnameinfo((struct sockaddr *)&from, fromlen, ntop, sizeof(ntop),
NULL, 0, NI_NUMERICHOST) != 0)
fatal("get_remote_hostname: getnameinfo NI_NUMERICHOST failed");
if (!use_dns)
return xstrdup(ntop);
debug3("Trying to reverse map address %.100s.", ntop);
/* Map the IP address to a host name. */
if (getnameinfo((struct sockaddr *)&from, fromlen, name, sizeof(name),
NULL, 0, NI_NAMEREQD) != 0) {
/* Host name not found. Use ip address. */
return xstrdup(ntop);
}
/*
* if reverse lookup result looks like a numeric hostname,
* someone is trying to trick us by PTR record like following:
* 1.1.1.10.in-addr.arpa. IN PTR 2.3.4.5
*/
memset(&hints, 0, sizeof(hints));
hints.ai_socktype = SOCK_DGRAM; /*dummy*/
hints.ai_flags = AI_NUMERICHOST;
if (getaddrinfo(name, NULL, &hints, &ai) == 0) {
logit("Nasty PTR record \"%s\" is set up for %s, ignoring",
name, ntop);
freeaddrinfo(ai);
return xstrdup(ntop);
}
/*
* Convert it to all lowercase (which is expected by the rest
* of this software).
*/
for (i = 0; name[i]; i++)
if (isupper(name[i]))
name[i] = (char)tolower(name[i]);
/*
* Map it back to an IP address and check that the given
* address actually is an address of this host. This is
* necessary because anyone with access to a name server can
* define arbitrary names for an IP address. Mapping from
* name to IP address can be trusted better (but can still be
* fooled if the intruder has access to the name server of
* the domain).
*/
memset(&hints, 0, sizeof(hints));
hints.ai_family = from.ss_family;
hints.ai_socktype = SOCK_STREAM;
if (getaddrinfo(name, NULL, &hints, &aitop) != 0) {
logit("reverse mapping checking getaddrinfo for %.700s "
"[%s] failed - POSSIBLE BREAK-IN ATTEMPT!", name, ntop);
return xstrdup(ntop);
}
/* Look for the address from the list of addresses. */
for (ai = aitop; ai; ai = ai->ai_next) {
if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop2,
sizeof(ntop2), NULL, 0, NI_NUMERICHOST) == 0 &&
(strcmp(ntop, ntop2) == 0))
break;
}
freeaddrinfo(aitop);
/* If we reached the end of the list, the address was not there. */
if (!ai) {
/* Address not found for the host name. */
logit("Address %.100s maps to %.600s, but this does not "
"map back to the address - POSSIBLE BREAK-IN ATTEMPT!",
ntop, name);
return xstrdup(ntop);
}
return xstrdup(name);
}