abc/lwip
1
0
Fork 0
mirror of https://git.savannah.nongnu.org/git/lwip.git synced 2026-05-20 15:17:05 +08:00
Code Issues Packages Projects Releases Wiki Activity

raw: core support for IP_HDRINCL socket option

Browse Source 
This patch adds a new RAW_FLAGS_HDRINCL flag to the raw core
implementation. When this flag is set on a RAW PCB, the raw send
routines expect the caller to supply an IP header for the given
packet, and will use that IP header instead of prepending one to
the packet themselves.

This feature allows the IP_HDRINCL socket option to be implemented
in higher layers with no further effort. Even thoguh that option is
traditionally supported for IPv4 sockets only (e.g., see RFC 3542
Sec. 3), the RAW_FLAGS_HDRINCL flag supports both IPv4 and IPv6, as
much of the lower-level infrastructure was already in place anyway.
This commit is contained in:
David van Moolenbroek
2017-01-05 15:32:54 +00:00
committed by Dirk Ziegelmeier
parent 162cc4d343
commit b59472cf63
3 changed files with 31 additions and 6 deletions
Download Patch File Download Diff File Expand all files Collapse all files

26
src/core/raw.c
View File

@@ -287,11 +287,9 @@ raw_recv(struct raw_pcb *pcb, raw_recv_fn recv, void *recv_arg)
/**
* @ingroup raw_raw
* Send the raw IP packet to the given address. Note that actually you cannot
* modify the IP headers (this is inconsistent with the receive callback where
* you actually get the IP headers), you can only specify the IP payload here.
* It requires some more changes in lwIP. (there will be a raw_send() function
* then.)
* Send the raw IP packet to the given address. An IP header will be prepended
* to the packet, unless the RAW_FLAGS_HDRINCL flag is set on the PCB. In that
* case, the packet must include an IP header, which will then be sent as is.
*
* @param pcb the raw pcb which to send
* @param p the IP payload to send
@@ -342,7 +340,9 @@ raw_sendto(struct raw_pcb *pcb, struct pbuf *p, const ip_addr_t *ipaddr)
/**
* @ingroup raw_raw
* Send the raw IP packet to the given address, using a particular outgoing
* netif and source IP address. An IP header will be prepended to the packet.
* netif and source IP address. An IP header will be prepended to the packet,
* unless the RAW_FLAGS_HDRINCL flag is set on the PCB. In that case, the
* packet must include an IP header, which will then be sent as is.
*
* @param pcb RAW PCB used to send the data
* @param p chain of pbufs to be sent
@@ -372,6 +372,20 @@ raw_sendto_if_src(struct raw_pcb *pcb, struct pbuf *p, const ip_addr_t *dst_ip,
IP6_HLEN);
#endif
/* Handle the HDRINCL option as an exception: none of the code below applies
* to this case, and sending the packet needs to be done differently too. */
if (pcb->flags & RAW_FLAGS_HDRINCL) {
/* A full header *must* be present in the first pbuf of the chain, as the
* output routines may access its fields directly. */
if (p->len < header_size) {
return ERR_VAL;
}
NETIF_SET_HWADDRHINT(netif, &pcb->addr_hint);
err = ip_output_if_hdrincl(p, src_ip, dst_ip, netif);
NETIF_SET_HWADDRHINT(netif, NULL);
return err;
}
/* not enough space to add an IP header to first pbuf in given p chain? */
if (pbuf_header(p, header_size)) {
/* allocate header in new pbuf */