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From a9af0f1d11b3ab12da9749d1f858dafb06c67bd8 Mon Sep 17 00:00:00 2001
From: Akihiro Suda <suda.akihiro@lab.ntt.co.jp>
Date: Wed, 6 Mar 2019 16:15:37 +0900
Subject: [PATCH 2/3] slirp: allow custom MTU
From slirp4netns project:
* https://github.com/rootless-containers/slirp4netns/commit/ea630a7e945cf538184ff1b1b4bd7b8ddc01993e
* https://github.com/rootless-containers/slirp4netns/commit/1508a66c93c223555f08651592dde3d2d708b166
* https://github.com/rootless-containers/slirp4netns/commit/19f3f41df4066d6103e6f882500e24db7ea7d9e1
* https://github.com/rootless-containers/slirp4netns/commit/a11abedafcc627ef0657999e63b211b0f26d4c02
* https://github.com/rootless-containers/slirp4netns/commit/2adbd7c449944d3b837164c86eedd3dcabbba1a6
Signed-off-by: Akihiro Suda <suda.akihiro@lab.ntt.co.jp>
---
slirp/src/dhcpv6.c | 2 +-
slirp/src/if.h | 6 ++++--
slirp/src/ip6_icmp.c | 4 ++--
slirp/src/ip6_input.c | 2 +-
slirp/src/ip_output.c | 4 ++--
slirp/src/libslirp.h | 4 ++++
slirp/src/mbuf.c | 8 ++++----
slirp/src/slirp.c | 11 ++++++++++-
slirp/src/slirp.h | 3 +++
slirp/src/tcp.h | 18 +++---------------
slirp/src/tcp_input.c | 6 +++---
slirp/src/tcp_subr.c | 2 +-
12 files changed, 38 insertions(+), 32 deletions(-)
diff --git a/slirp/src/dhcpv6.c b/slirp/src/dhcpv6.c
index 3c8f420912..53bb90b541 100644
--- a/slirp/src/dhcpv6.c
+++ b/slirp/src/dhcpv6.c
@@ -177,7 +177,7 @@ static void dhcpv6_info_request(Slirp *slirp, struct sockaddr_in6 *srcsas,
*resp++ = OPTION_BOOTFILE_URL >> 8; /* option-code high byte */
*resp++ = OPTION_BOOTFILE_URL; /* option-code low byte */
- smaxlen = (uint8_t *)m->m_data + IF_MTU - (resp + 2);
+ smaxlen = (uint8_t *)m->m_data + slirp->if_mtu - (resp + 2);
slen = snprintf((char *)resp + 2, smaxlen,
"tftp://[%02x%02x:%02x%02x:%02x%02x:%02x%02x:"
"%02x%02x:%02x%02x:%02x%02x:%02x%02x]/%s",
diff --git a/slirp/src/if.h b/slirp/src/if.h
index b71c37d6ea..7a47a12ab2 100644
--- a/slirp/src/if.h
+++ b/slirp/src/if.h
@@ -11,8 +11,10 @@
#define IF_AUTOCOMP 0x04 /* Autodetect (default) */
#define IF_NOCIDCOMP 0x08 /* CID compression */
-#define IF_MTU 1500
-#define IF_MRU 1500
+#define IF_MTU_DEFAULT 1500
+#define IF_MTU_MAX 65521
+#define IF_MRU_DEFAULT 1500
+#define IF_MRU_MAX 65521
#define IF_COMP IF_AUTOCOMP /* Flags for compression */
/* 2 for alignment, 14 for ethernet */
diff --git a/slirp/src/ip6_icmp.c b/slirp/src/ip6_icmp.c
index 5642457fdd..dcace933a9 100644
--- a/slirp/src/ip6_icmp.c
+++ b/slirp/src/ip6_icmp.c
@@ -93,7 +93,7 @@ void icmp6_send_error(struct mbuf *m, uint8_t type, uint8_t code)
rip->ip_nh = IPPROTO_ICMPV6;
const int error_data_len = MIN(m->m_len,
- IF_MTU - (sizeof(struct ip6) + ICMP6_ERROR_MINLEN));
+ slirp->if_mtu - (sizeof(struct ip6) + ICMP6_ERROR_MINLEN));
rip->ip_pl = htons(ICMP6_ERROR_MINLEN + error_data_len);
t->m_len = sizeof(struct ip6) + ntohs(rip->ip_pl);
@@ -110,7 +110,7 @@ void icmp6_send_error(struct mbuf *m, uint8_t type, uint8_t code)
ricmp->icmp6_err.unused = 0;
break;
case ICMP6_TOOBIG:
- ricmp->icmp6_err.mtu = htonl(IF_MTU);
+ ricmp->icmp6_err.mtu = htonl(slirp->if_mtu);
break;
case ICMP6_PARAMPROB:
/* TODO: Handle this case */
diff --git a/slirp/src/ip6_input.c b/slirp/src/ip6_input.c
index d9d2b7e9cd..dfcbfd6a78 100644
--- a/slirp/src/ip6_input.c
+++ b/slirp/src/ip6_input.c
@@ -44,7 +44,7 @@ void ip6_input(struct mbuf *m)
goto bad;
}
- if (ntohs(ip6->ip_pl) > IF_MTU) {
+ if (ntohs(ip6->ip_pl) > slirp->if_mtu) {
icmp6_send_error(m, ICMP6_TOOBIG, 0);
goto bad;
}
diff --git a/slirp/src/ip_output.c b/slirp/src/ip_output.c
index 8560197cf6..cd2ea7c72d 100644
--- a/slirp/src/ip_output.c
+++ b/slirp/src/ip_output.c
@@ -73,7 +73,7 @@ ip_output(struct socket *so, struct mbuf *m0)
/*
* If small enough for interface, can just send directly.
*/
- if ((uint16_t)ip->ip_len <= IF_MTU) {
+ if ((uint16_t)ip->ip_len <= slirp->if_mtu) {
ip->ip_len = htons((uint16_t)ip->ip_len);
ip->ip_off = htons((uint16_t)ip->ip_off);
ip->ip_sum = 0;
@@ -92,7 +92,7 @@ ip_output(struct socket *so, struct mbuf *m0)
goto bad;
}
- len = (IF_MTU - hlen) &~ 7; /* ip databytes per packet */
+ len = (slirp->if_mtu - hlen) &~ 7; /* ip databytes per packet */
if (len < 8) {
error = -1;
goto bad;
diff --git a/slirp/src/libslirp.h b/slirp/src/libslirp.h
index bd141964ff..4e2d4ee6c7 100644
--- a/slirp/src/libslirp.h
+++ b/slirp/src/libslirp.h
@@ -83,6 +83,10 @@ typedef struct SlirpConfig{
struct in6_addr vnameserver6;
const char **vdnssearch;
const char *vdomainname;
+ /* Default: IF_MTU_DEFAULT */
+ int if_mtu;
+ /* Default: IF_MRU_DEFAULT */
+ int if_mru;
} SlirpConfig;
Slirp *slirp_initx(const SlirpConfig *cfg, const SlirpCb *callbacks, void *opaque);
diff --git a/slirp/src/mbuf.c b/slirp/src/mbuf.c
index 800406ca9e..b1ac229b7b 100644
--- a/slirp/src/mbuf.c
+++ b/slirp/src/mbuf.c
@@ -20,8 +20,8 @@
/*
* Find a nice value for msize
*/
-#define SLIRP_MSIZE\
- (offsetof(struct mbuf, m_dat) + IF_MAXLINKHDR + TCPIPHDR_DELTA + IF_MTU)
+#define SLIRP_MSIZE(mtu)\
+ (offsetof(struct mbuf, m_dat) + IF_MAXLINKHDR + TCPIPHDR_DELTA + (mtu))
void
m_init(Slirp *slirp)
@@ -68,7 +68,7 @@ m_get(Slirp *slirp)
DEBUG_CALL("m_get");
if (slirp->m_freelist.qh_link == &slirp->m_freelist) {
- m = g_malloc(SLIRP_MSIZE);
+ m = g_malloc(SLIRP_MSIZE(slirp->if_mtu));
slirp->mbuf_alloced++;
if (slirp->mbuf_alloced > MBUF_THRESH)
flags = M_DOFREE;
@@ -83,7 +83,7 @@ m_get(Slirp *slirp)
m->m_flags = (flags | M_USEDLIST);
/* Initialise it */
- m->m_size = SLIRP_MSIZE - offsetof(struct mbuf, m_dat);
+ m->m_size = SLIRP_MSIZE(slirp->if_mtu) - offsetof(struct mbuf, m_dat);
m->m_data = m->m_dat;
m->m_len = 0;
m->m_nextpkt = NULL;
diff --git a/slirp/src/slirp.c b/slirp/src/slirp.c
index ee5833e18b..8c02913769 100644
--- a/slirp/src/slirp.c
+++ b/slirp/src/slirp.c
@@ -276,6 +276,13 @@ Slirp *slirp_initx(const SlirpConfig *cfg, const SlirpCb *callbacks, void *opaqu
if (cfg == NULL) {
return NULL;
}
+ if (cfg->if_mtu > IF_MTU_MAX) {
+ return NULL;
+ }
+ if (cfg->if_mru > IF_MRU_MAX) {
+ return NULL;
+ }
+
slirp = g_malloc0(sizeof(Slirp));
slirp_init_once();
@@ -316,6 +323,8 @@ Slirp *slirp_initx(const SlirpConfig *cfg, const SlirpCb *callbacks, void *opaqu
if (cfg->vdnssearch) {
translate_dnssearch(slirp, cfg->vdnssearch);
}
+ slirp->if_mtu = cfg->if_mtu == 0 ? IF_MTU_DEFAULT : cfg->if_mtu;
+ slirp->if_mru = cfg->if_mru == 0 ? IF_MRU_DEFAULT : cfg->if_mru;
return slirp;
}
@@ -924,7 +933,7 @@ static int if_encap6(Slirp *slirp, struct mbuf *ifm, struct ethhdr *eh,
*/
int if_encap(Slirp *slirp, struct mbuf *ifm)
{
- uint8_t buf[1600];
+ uint8_t buf[IF_MTU_MAX+100];
struct ethhdr *eh = (struct ethhdr *)buf;
uint8_t ethaddr[ETH_ALEN];
const struct ip *iph = (const struct ip *)ifm->m_data;
diff --git a/slirp/src/slirp.h b/slirp/src/slirp.h
index 39580934f3..1c485be36f 100644
--- a/slirp/src/slirp.h
+++ b/slirp/src/slirp.h
@@ -146,6 +146,9 @@ struct Slirp {
int restricted;
struct gfwd_list *guestfwd_list;
+ int if_mtu;
+ int if_mru;
+
/* mbuf states */
struct quehead m_freelist;
struct quehead m_usedlist;
diff --git a/slirp/src/tcp.h b/slirp/src/tcp.h
index 79d3251bb5..fca5c13db5 100644
--- a/slirp/src/tcp.h
+++ b/slirp/src/tcp.h
@@ -41,8 +41,9 @@ typedef uint32_t tcp_seq;
#define PR_SLOWHZ 2 /* 2 slow timeouts per second (approx) */
#define PR_FASTHZ 5 /* 5 fast timeouts per second (not important) */
-#define TCP_SNDSPACE 8192
-#define TCP_RCVSPACE 8192
+#define TCP_SNDSPACE 1024*128
+#define TCP_RCVSPACE 1024*128
+#define TCP_MAXSEG_MAX 32768
/*
* TCP header.
@@ -99,19 +100,6 @@ struct tcphdr {
#define TCPOLEN_TSTAMP_APPA (TCPOLEN_TIMESTAMP+2) /* appendix A */
#endif
-/*
- * Default maximum segment size for TCP.
- * With an IP MSS of 576, this is 536,
- * but 512 is probably more convenient.
- * This should be defined as MIN(512, IP_MSS - sizeof (struct tcpiphdr)).
- *
- * We make this 1460 because we only care about Ethernet in the qemu context.
- */
-#undef TCP_MSS
-#define TCP_MSS 1460
-#undef TCP6_MSS
-#define TCP6_MSS 1440
-
#undef TCP_MAXWIN
#define TCP_MAXWIN 65535 /* largest value for (unscaled) window */
diff --git a/slirp/src/tcp_input.c b/slirp/src/tcp_input.c
index 50a1145ec9..14a489e61a 100644
--- a/slirp/src/tcp_input.c
+++ b/slirp/src/tcp_input.c
@@ -1522,11 +1522,11 @@ tcp_mss(struct tcpcb *tp, unsigned offer)
switch (so->so_ffamily) {
case AF_INET:
- mss = MIN(IF_MTU, IF_MRU) - sizeof(struct tcphdr)
+ mss = MIN(so->slirp->if_mtu, so->slirp->if_mru) - sizeof(struct tcphdr)
- sizeof(struct ip);
break;
case AF_INET6:
- mss = MIN(IF_MTU, IF_MRU) - sizeof(struct tcphdr)
+ mss = MIN(so->slirp->if_mtu, so->slirp->if_mru) - sizeof(struct tcphdr)
- sizeof(struct ip6);
break;
default:
@@ -1537,7 +1537,7 @@ tcp_mss(struct tcpcb *tp, unsigned offer)
mss = MIN(mss, offer);
mss = MAX(mss, 32);
if (mss < tp->t_maxseg || offer != 0)
- tp->t_maxseg = mss;
+ tp->t_maxseg = MIN(mss, TCP_MAXSEG_MAX);
tp->snd_cwnd = mss;
diff --git a/slirp/src/tcp_subr.c b/slirp/src/tcp_subr.c
index fde9207b0c..e88e51e39c 100644
--- a/slirp/src/tcp_subr.c
+++ b/slirp/src/tcp_subr.c
@@ -259,7 +259,7 @@ tcp_newtcpcb(struct socket *so)
memset((char *) tp, 0, sizeof(struct tcpcb));
tp->seg_next = tp->seg_prev = (struct tcpiphdr*)tp;
- tp->t_maxseg = (so->so_ffamily == AF_INET) ? TCP_MSS : TCP6_MSS;
+ tp->t_maxseg = MIN(so->slirp->if_mtu - ((so->so_ffamily == AF_INET) ? 40 : 60), TCP_MAXSEG_MAX);
tp->t_flags = TCP_DO_RFC1323 ? (TF_REQ_SCALE|TF_REQ_TSTMP) : 0;
tp->t_socket = so;
--
2.20.1
|
