.\" Copyright (C) 2019 VirtualSquare. Project Leader: Renzo Davoli
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.TH "LIBVDESLIRPFWD" "3" "January 2020" "VirtualSquare"
.SH "NAME"
vdeslirp_add_fwd, vdeslirp_remove_fwd, vdeslirp_add_unixfwd, vdeslirp_remove_unixfwd, vdeslirp_add_cmdexec \- simple API for slirp, port forwarding
.SH "SYNOPSIS"
\fB#include <libvdeslirp\.h>\fR
.P
\fBint vdeslirp_add_fwd(struct vdeslirp *\fR\fIslirp\fR\fB, int\fR \fIis_udp\fR\fB, struct in_addr\fR \fIhost_addr\fR\fB, int\fR \fIhost_port\fR\fB, struct in_addr\fR \fIguest_addr\fR\fB, int\fR \fIguest_port\fR\fB);\fR
.P
\fBint vdeslirp_remove_fwd(struct vdeslirp *\fR\fIslirp\fR\fB, int\fR \fIis_udp\fR\fB, struct in_addr\fR \fIhost_addr\fR\fB, int\fR \fIhost_port\fR\fB);\fR
.P
\fBint vdeslirp_add_unixfwd(struct vdeslirp *\fR\fIslirp\fR\fB, char *\fR\fIpath\fR\fB, struct in_addr\fR \fIguest_addr\fR\fB, int\fR \fIguest_port\fR\fB);\fR
.P
\fBint vdeslirp_remove_unixfwd(struct vdeslirp *\fR\fIslirp\fR\fB, struct in_addr\fR \fIguest_addr\fR\fB, int\fR \fIguest_port\fR\fB);\fR
.P
\fBint vdeslirp_add_cmdexec(struct vdeslirp *\fR\fIslirp\fR\fB, const char *\fR\fIcmdline\fR\fB, struct in_addr *\fR\fIguest_addr\fR\fB, int\fR \fIguest_port\fR\fB);\fR
.P
\fBint vdeslirp_remove_cmdexec(struct vdeslirp *\fR\fIslirp\fR\fB, struct in_addr\fR \fIguest_addr\fR\fB, int\fR \fIguest_port\fR\fB);\fR
.SH "DESCRIPTION"
Slirp, see libvdelirp(3), is a TCP/IP emulator\. Slirp generates a virtual network using standard user privileges (no need for root access of CAP_NET_ADMIN)\. These functions manage port forwarding services\.
.P
\fBvdeslirp_add_fwd\fR and \fBvdeslirp_remove_fwd\fR respectively add and remove udp or tcp port forwarding services (depending upon the value of is_udp)\. \fIhost_addr\fR and \fIhost_port\fR are the IP address and port number bound for the service in the host system\. All the connections or datagrams to \fIhost_addr\fR and \fIhost_port\fR will be diverted to \fIguest_addr\fR and \fIguest_port\fR in the slirp virtual network\.
.P
\fBvdeslirp_add_unixfwd\fR and \fBvdeslirp_remove_unixfwd\fR respectively add and remove a forwarding service towards a \fBPF_UNIX\fR stream socket on the hosting system\. All the connections from a node of the virtual network to \fIguest_addr\fR and \fIguest_port\fR will be diverted to the \fBPF_UNIX\fR bound to the pathname path\. This feature is commonly used to run X\-window clients in the virtual network (e\.g\. the value of path could be \fB/tmp/\.X11\-unix/X0\fR)\.
.P
If libslirp does not support \fBslirp_add_unix\fR, \fBvdeslirp_add_unixfwd\fR is implemented by a workaround based on \fBnc\fR(1)\.
.P
\fBvdeslirp_cmd_fwd\fR adds a forwarding service to a command\. A TCP connection to \fIguest_addr\fR and \fIguest_port\fR activates the command \fIcmdline\fR\. Data exchanged on the TCP connection is forwarded as stdin/stdout to the command\.
.P
\fBvdeslirp_remove_cmdexec\fR removes a command forwarding service\.
.SH "RETURN VALUE"
All these functions return 0 in case of success, \-1 otherwise (and \fBerrno\fR is set consequently)\. \fBvdeslirp_remove_cmdexec\fR and \fBvdeslirp_remove_unixfwd\fR return \-1 and set errno to \fBENOSYS\fR if libslirp does not support \fBslirp_remove_guestfwd\fR\.
.SH "SEE ALSO"
\fBlibvdeslirp\fR(3), \fBlibvdeslirpcfg\fR(3)
.SH "BUGS"
Bug reports should be addressed to <info@virtualsquare\.org>
.SH "AUTHOR"
VirtualSquare\. Project leader: Renzo Davoli\.