#include <config.h>
#include <stdio.h>
#include <string.h>
#include <signal.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <fcntl.h>
#include <sys/types.h>
#include <sys/param.h>
#include <sys/stat.h>
#include <sys/un.h>
#include <syslog.h>
#include <netdb.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <assert.h>
#include <ctype.h>
#include <errno.h>
#include <sasl/sasl.h>
#include <sasl/saslutil.h>
#include "prot.h"
#include "backend.h"
#include "global.h"
#include "xmalloc.h"
#include "xstrlcpy.h"
#include "xstrlcat.h"
#include "iptostring.h"
#include "util.h"
static char *ask_capability(struct protstream *pout, struct protstream *pin,
struct protocol_t *prot, unsigned long *capa,
int banner)
{
char str[4096];
char *ret = NULL, *tmp;
struct capa_t *c;
*capa = 0;
if (!banner && prot->capa_cmd.cmd) {
prot_printf(pout, "%s\r\n", prot->capa_cmd.cmd);
prot_flush(pout);
}
do {
if (prot_fgets(str, sizeof(str), pin) == NULL) {
return NULL;
}
for (c = prot->capa_cmd.capa; c->str; c++) {
if ((tmp = strstr(str, c->str)) != NULL) {
*capa = *capa | c->flag;
if (c->flag == CAPA_AUTH) {
if (prot->capa_cmd.parse_mechlist)
ret = prot->capa_cmd.parse_mechlist(str, prot);
else
ret = xstrdup(tmp+strlen(c->str));
}
}
}
} while (strncasecmp(str, prot->capa_cmd.resp, strlen(prot->capa_cmd.resp)));
return ret;
}
static int do_starttls(struct backend *s, struct tls_cmd_t *tls_cmd)
{
#ifndef HAVE_SSL
return -1;
#else
char buf[2048];
int r;
int *layerp;
char *auth_id;
sasl_ssf_t ssf;
prot_printf(s->out, "%s\r\n", tls_cmd->cmd);
prot_flush(s->out);
if (!prot_fgets(buf, sizeof(buf), s->in) ||
strncmp(buf, tls_cmd->ok, strlen(tls_cmd->ok)))
return -1;
r = tls_init_clientengine(5, "", "");
if (r == -1) return -1;
layerp = (int *) &ssf;
r = tls_start_clienttls(s->in->fd, s->out->fd, layerp, &auth_id,
&s->tlsconn, &s->tlssess);
if (r == -1) return -1;
r = sasl_setprop(s->saslconn, SASL_SSF_EXTERNAL, &ssf);
if (r != SASL_OK) return -1;
r = sasl_setprop(s->saslconn, SASL_AUTH_EXTERNAL, auth_id);
if (r != SASL_OK) return -1;
prot_settls(s->in, s->tlsconn);
prot_settls(s->out, s->tlsconn);
return 0;
#endif
}
static int backend_authenticate(struct backend *s, struct protocol_t *prot,
char **mechlist, const char *userid,
sasl_callback_t *cb, const char **status)
{
int r;
sasl_security_properties_t *secprops = NULL;
struct sockaddr_storage saddr_l, saddr_r;
char remoteip[60], localip[60];
socklen_t addrsize;
int local_cb = 0;
char buf[2048], optstr[128], *p;
const char *mech_conf, *pass;
if (!cb) {
local_cb = 1;
strlcpy(optstr, s->hostname, sizeof(optstr));
p = strchr(optstr, '.');
if (p) *p = '\0';
strlcat(optstr, "_password", sizeof(optstr));
pass = config_getoverflowstring(optstr, NULL);
if(!pass) pass = config_getstring(IMAPOPT_PROXY_PASSWORD);
cb = mysasl_callbacks(userid,
config_getstring(IMAPOPT_PROXY_AUTHNAME),
config_getstring(IMAPOPT_PROXY_REALM),
pass);
}
addrsize=sizeof(struct sockaddr_storage);
if (getpeername(s->sock, (struct sockaddr *)&saddr_r, &addrsize) != 0)
return SASL_FAIL;
if(iptostring((struct sockaddr *)&saddr_r, addrsize, remoteip, 60) != 0)
return SASL_FAIL;
addrsize=sizeof(struct sockaddr_storage);
if (getsockname(s->sock, (struct sockaddr *)&saddr_l, &addrsize)!=0)
return SASL_FAIL;
if(iptostring((struct sockaddr *)&saddr_l, addrsize, localip, 60) != 0)
return SASL_FAIL;
r = sasl_client_new(prot->sasl_service, s->hostname, localip, remoteip, cb,
(userid && *userid ? SASL_NEED_PROXY : 0) |
(prot->sasl_cmd.parse_success ? SASL_SUCCESS_DATA : 0),
&s->saslconn);
if (r != SASL_OK) {
return r;
}
secprops = mysasl_secprops(SASL_SEC_NOPLAINTEXT);
r = sasl_setprop(s->saslconn, SASL_SEC_PROPS, secprops);
if (r != SASL_OK) {
return r;
}
strcpy(buf, s->hostname);
p = strchr(buf, '.');
if (p) *p = '\0';
strcat(buf, "_mechs");
mech_conf = config_getoverflowstring(buf, NULL);
if(!mech_conf) {
mech_conf = config_getstring(IMAPOPT_FORCE_SASL_CLIENT_MECH);
}
do {
if (mech_conf) {
free(*mechlist);
*mechlist = xstrdup(mech_conf);
}
if (*mechlist) {
saslclient(s->saslconn, &prot->sasl_cmd, *mechlist,
s->in, s->out, &r, status);
free(*mechlist);
*mechlist = NULL;
}
else r = SASL_NOMECH;
} while (r == SASL_NOMECH && CAPA(s, CAPA_STARTTLS) &&
do_starttls(s, &prot->tls_cmd) != -1 &&
(*mechlist = ask_capability(s->out, s->in, prot, &s->capability, 0)));
if (local_cb) free_callbacks(cb);
if (r == SASL_OK) {
prot_setsasl(s->in, s->saslconn);
prot_setsasl(s->out, s->saslconn);
}
return r;
}
static int timedout = 0;
static void timed_out(int sig)
{
if (sig == SIGALRM) {
timedout = 1;
} else {
fatal("Bad signal in timed_out", EC_SOFTWARE);
}
}
struct backend *backend_connect(struct backend *ret_backend, const char *server,
struct protocol_t *prot, const char *userid,
sasl_callback_t *cb, const char **auth_status)
{
int sock = -1;
int r;
int err = -1;
struct addrinfo hints, *res0 = NULL, *res;
struct sockaddr_un sunsock;
char buf[2048], *mechlist = NULL;
struct sigaction action;
struct backend *ret;
if (!ret_backend) {
ret = xmalloc(sizeof(struct backend));
memset(ret, 0, sizeof(struct backend));
strlcpy(ret->hostname, server, sizeof(ret->hostname));
ret->timeout = NULL;
}
else
ret = ret_backend;
if (server[0] == '/') {
res0 = &hints;
memset(res0, 0, sizeof(struct addrinfo));
res0->ai_family = PF_UNIX;
res0->ai_socktype = SOCK_STREAM;
res0->ai_addr = (struct sockaddr *) &sunsock;
res0->ai_addrlen = sizeof(sunsock.sun_family) + strlen(server) + 1;
#ifdef SIN6_LEN
res0->ai_addrlen += sizeof(sunsock.sun_len);
sunsock.sun_len = res0->ai_addrlen;
#endif
sunsock.sun_family = AF_UNIX;
strlcpy(sunsock.sun_path, server, sizeof(sunsock.sun_path));
strlcpy(ret->hostname, config_servername, sizeof(ret->hostname));
}
else {
memset(&hints, 0, sizeof(hints));
hints.ai_family = PF_UNSPEC;
hints.ai_socktype = SOCK_STREAM;
err = getaddrinfo(server, prot->service, &hints, &res0);
if (err) {
syslog(LOG_ERR, "getaddrinfo(%s) failed: %s",
server, gai_strerror(err));
if (!ret_backend) free(ret);
return NULL;
}
}
timedout = 0;
action.sa_flags = 0;
action.sa_handler = timed_out;
if(sigaction(SIGALRM, &action, NULL) < 0)
{
syslog(LOG_ERR, "Setting timeout in backend_connect failed: sigaction: %m");
}
for (res = res0; res; res = res->ai_next) {
sock = socket(res->ai_family, res->ai_socktype, res->ai_protocol);
if (sock < 0)
continue;
alarm(config_getint(IMAPOPT_CLIENT_TIMEOUT));
if (connect(sock, res->ai_addr, res->ai_addrlen) >= 0)
break;
if(errno == EINTR && timedout == 1)
errno = ETIMEDOUT;
close(sock);
sock = -1;
}
alarm(0);
signal(SIGALRM, SIG_IGN);
if (sock < 0) {
if (res0 != &hints)
freeaddrinfo(res0);
syslog(LOG_ERR, "connect(%s) failed: %m", server);
if (!ret_backend) free(ret);
return NULL;
}
memcpy(&ret->addr, res->ai_addr, res->ai_addrlen);
if (res0 != &hints)
freeaddrinfo(res0);
ret->in = prot_new(sock, 0);
ret->out = prot_new(sock, 1);
ret->sock = sock;
prot_setflushonread(ret->in, ret->out);
ret->prot = prot;
if (!prot->banner.is_capa) {
do {
if (!prot_fgets(buf, sizeof(buf), ret->in)) {
syslog(LOG_ERR,
"backend_connect(): couldn't read initial greeting: %s",
ret->in->error ? ret->in->error : "(null)");
if (!ret_backend) free(ret);
close(sock);
return NULL;
}
} while (strncasecmp(buf, prot->banner.resp,
strlen(prot->banner.resp)));
}
mechlist = ask_capability(ret->out, ret->in, prot, &ret->capability,
prot->banner.is_capa);
if ((server[0] != '/') || strcmp(prot->sasl_service, "lmtp")) {
if ((r = backend_authenticate(ret, prot, &mechlist, userid,
cb, auth_status))) {
syslog(LOG_ERR, "couldn't authenticate to backend server: %s",
sasl_errstring(r, NULL, NULL));
if (!ret_backend) free(ret);
close(sock);
ret = NULL;
}
}
if (mechlist) free(mechlist);
if (!ret_backend) ret_backend = ret;
return ret;
}
int backend_ping(struct backend *s)
{
char buf[1024];
if (!s || !s->prot->ping_cmd.cmd) return 0;
if (!s->sock == -1) return -1;
prot_printf(s->out, "%s\r\n", s->prot->ping_cmd.cmd);
prot_flush(s->out);
for (;;) {
if (!prot_fgets(buf, sizeof(buf), s->in)) {
return -1;
} else if (s->prot->ping_cmd.unsol &&
!strncmp(s->prot->ping_cmd.unsol, buf,
strlen(s->prot->ping_cmd.unsol))) {
continue;
} else {
return strncmp(s->prot->ping_cmd.ok, buf,
strlen(s->prot->ping_cmd.ok));
}
}
}
void backend_disconnect(struct backend *s)
{
char buf[1024];
if (!s || s->sock == -1) return;
if (!prot_error(s->in)) {
if (s->prot->logout_cmd.cmd) {
prot_printf(s->out, "%s\r\n", s->prot->logout_cmd.cmd);
prot_flush(s->out);
for (;;) {
if (!prot_fgets(buf, sizeof(buf), s->in)) {
break;
} else if (s->prot->logout_cmd.unsol &&
!strncmp(s->prot->logout_cmd.unsol, buf,
strlen(s->prot->logout_cmd.unsol))) {
continue;
} else {
break;
}
}
}
}
prot_NONBLOCK(s->in);
prot_fill(s->in);
#ifdef HAVE_SSL
if (s->tlsconn) {
tls_reset_servertls(&s->tlsconn);
s->tlsconn = NULL;
}
#endif
cyrus_close_sock(s->sock);
s->sock = -1;
prot_free(s->in);
prot_free(s->out);
s->in = s->out = NULL;
if(s->saslconn) {
sasl_dispose(&(s->saslconn));
s->saslconn = NULL;
}
}