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/* ISC license. */
#include <sys/uio.h>
#include <errno.h>
#include <unistd.h>
#include <tls.h>
#include <skalibs/error.h>
#include <skalibs/buffer.h>
#include <skalibs/strerr.h>
#include <skalibs/iopause.h>
#include <skalibs/djbunix.h>
#include <s6-networking/stls.h>
typedef struct tlsbuf_s tlsbuf_t, *tlsbuf_t_ref ;
struct tlsbuf_s
{
buffer b ;
unsigned char blockedonother : 1 ;
char buf[STLS_BUFSIZE] ;
} ;
static inline int buffer_tls_flush (struct tls *ctx, tlsbuf_t *b)
{
struct iovec v[2] ;
ssize_t r, w ;
buffer_rpeek(&b[0].b, v) ;
r = tls_write(ctx, v[0].iov_base, v[0].iov_len) ;
switch (r)
{
case -1 : return -1 ;
case TLS_WANT_POLLIN :
if (b[1].blockedonother) strerr_dief1x(101, "TLS deadlock") ;
b[0].blockedonother = 1 ;
case TLS_WANT_POLLOUT : return 0 ;
default : break ;
}
w = r ;
if ((size_t)w == v[0].iov_len && v[1].iov_len)
{
r = tls_write(ctx, v[1].iov_base, v[1].iov_len) ;
switch (r)
{
case TLS_WANT_POLLIN :
if (b[1].blockedonother) strerr_dief1x(101, "TLS deadlock") ;
b[0].blockedonother = 1 ;
case -1 :
case TLS_WANT_POLLOUT :
buffer_rseek(&b[0].b, w) ;
return 0 ;
default : break ;
}
w += r ;
}
buffer_rseek(&b[0].b, w) ;
return 1 ;
}
static inline int buffer_tls_fill (struct tls *ctx, tlsbuf_t *b)
{
struct iovec v[2] ;
ssize_t r, w ;
int ok = 1 ;
buffer_wpeek(&b[1].b, v) ;
r = tls_read(ctx, v[0].iov_base, v[0].iov_len) ;
switch (r)
{
case 0 : return -2 ;
case -1 : return -1 ;
case TLS_WANT_POLLOUT :
if (b[0].blockedonother) strerr_dief1x(101, "TLS deadlock") ;
b[1].blockedonother = 1 ;
case TLS_WANT_POLLIN : return 0 ;
default : break ;
}
w = r ;
if ((size_t)w == v[0].iov_len && v[1].iov_len)
{
r = tls_read(ctx, v[1].iov_base, v[1].iov_len) ;
switch (r)
{
case TLS_WANT_POLLOUT :
if (b[0].blockedonother) strerr_dief1x(101, "TLS deadlock") ;
b[1].blockedonother = 1 ;
case -1 :
case TLS_WANT_POLLIN :
buffer_wseek(&b[1].b, w) ;
return 0 ;
case 0 : ok = -1 ; errno = EPIPE ;
default : break ;
}
w += r ;
}
buffer_wseek(&b[1].b, w) ;
return ok ;
}
static void send_closenotify (struct tls *ctx, int const *fds)
{
iopause_fd x = { .fd = fds[3], .events = IOPAUSE_WRITE } ;
while (tls_close(ctx) == TLS_WANT_POLLOUT)
iopause_g(&x, 1, 0) ;
}
static void closeit (struct tls *ctx, int *fds, int closenotify)
{
if (!closenotify) fd_shutdown(fds[3], 1) ;
else if (fds[2] >= 0) send_closenotify(ctx, fds) ;
fd_close(fds[3]) ; fds[3] = -1 ;
}
void stls_run (struct tls *ctx, int *fds, uint32_t options, unsigned int verbosity)
{
tlsbuf_t b[2] = { { .blockedonother = 0 }, { .blockedonother = 0 } } ;
iopause_fd x[4] ;
unsigned int xindex[4] ;
if (ndelay_on(fds[0]) < 0
|| ndelay_on(fds[1]) < 0
|| ndelay_on(fds[2]) < 0
|| ndelay_on(fds[3]) < 0)
strerr_diefu1sys(111, "set fds non-blocking") ;
buffer_init(&b[0].b, &buffer_read, fds[0], b[0].buf, STLS_BUFSIZE) ;
buffer_init(&b[1].b, &buffer_write, fds[1], b[1].buf, STLS_BUFSIZE) ;
for (;;)
{
unsigned int j = 0 ;
int r ;
/* poll() preparation */
if (fds[0] >= 0 && buffer_isreadable(&b[0].b))
{
x[j].fd = fds[0] ;
x[j].events = IOPAUSE_READ ;
xindex[0] = j++ ;
}
else xindex[0] = 4 ;
if (fds[1] >= 0 && buffer_iswritable(&b[1].b))
{
x[j].fd = fds[1] ;
x[j].events = IOPAUSE_WRITE ;
xindex[1] = j++ ;
}
else xindex[1] = 4 ;
if (fds[2] >= 0 && !b[1].blockedonother && buffer_isreadable(&b[1].b))
{
x[j].fd = fds[2] ;
x[j].events = IOPAUSE_READ ;
xindex[2] = j++ ;
}
else xindex[2] = 4 ;
if (fds[3] >= 0 && !b[0].blockedonother && buffer_iswritable(&b[0].b))
{
x[j].fd = fds[3] ;
x[j].events = IOPAUSE_WRITE ;
xindex[3] = j++ ;
}
else xindex[3] = 4 ;
if (xindex[0] == 4 && xindex[1] == 4 && xindex[3] == 4) break ;
/* poll() */
r = iopause_g(x, j, 0) ;
if (r < 0) strerr_diefu1sys(111, "iopause") ;
else if (!r) break ;
while (j--)
if (x[j].revents & IOPAUSE_EXCEPT)
x[j].revents |= IOPAUSE_READ | IOPAUSE_WRITE ;
/* Flush to local */
if (xindex[1] < 4 && x[xindex[1]].revents & IOPAUSE_WRITE)
{
r = buffer_flush(&b[1].b) ;
if (!r && !error_isagain(errno))
{
strerr_warnwu1sys("write to application") ;
if (fds[2] >= 0)
{
if (options & 1) fd_shutdown(fds[2], 0) ;
fd_close(fds[2]) ; fds[2] = -1 ;
xindex[2] = 4 ;
}
r = 1 ;
}
if (r && fds[2] < 0)
{
fd_close(fds[1]) ; fds[1] = -1 ;
}
}
/* Flush to remote */
if (xindex[3] < 4 && x[xindex[3]].revents & IOPAUSE_WRITE)
{
r = buffer_tls_flush(ctx, b) ;
if (r < 0)
{
strerr_warnwu2x("write to peer: ", tls_error(ctx)) ;
fd_close(fds[0]) ; fds[0] = -1 ;
xindex[0] = 4 ;
}
if (r && fds[0] < 0)
closeit(ctx, fds, options & 1) ;
}
/* Fill from local */
if (xindex[0] < 4 && x[xindex[0]].revents & IOPAUSE_READ)
{
r = sanitize_read(buffer_fill(&b[0].b)) ;
if (r < 0)
{
if (errno != EPIPE) strerr_warnwu1sys("read from application") ;
fd_close(fds[0]) ; fds[0] = -1 ;
if (buffer_isempty(&b[0].b))
closeit(ctx, fds, options & 1) ;
}
}
/* Fill from remote */
if (xindex[2] < 4 && x[xindex[2]].revents & IOPAUSE_READ)
{
r = buffer_tls_fill(ctx, b) ;
if (r < 0)
{
if (r == -1) strerr_warnwu2x("read from peer: ", tls_error(ctx)) ;
if (!(options & 1)) fd_shutdown(fds[2], 0) ;
/*
XXX: We need a way to detect when we've received a close_notify,
because then we need to trigger a write and then shut the engine
down. This is orthogonal to options&1, it only means that the
peer sent a close_notify.
As for now, libtls doesn't offer an API to detect that, so we
do nothing special - we just wait until our app sends EOF.
*/
fd_close(fds[2]) ; fds[2] = -1 ;
if (buffer_isempty(&b[1].b))
{
fd_close(fds[1]) ; fds[1] = -1 ;
}
}
}
}
_exit(0) ;
}
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