Hi Samuel, On 2/7/19 3:03 PM, Samuel Thibault wrote: > From: Marc-André Lureau <marcandre.lur...@redhat.com> > > Use a more descriptive name for the callback. > > Reuse the SlirpWriteCb type. Wrap it to check that all data has been written. > > Return a ssize_t for potential error handling and data-loss reporting. > > Signed-off-by: Marc-André Lureau <marcandre.lur...@redhat.com> > Signed-off-by: Samuel Thibault <samuel.thiba...@ens-lyon.org> > --- > include/net/net.h | 2 +- > net/net.c | 4 ++-- > net/slirp.c | 9 +++++---- > slirp/libslirp.h | 11 +++++++---- > slirp/ncsi.c | 2 +- > slirp/slirp.c | 18 +++++++++++++++--- > slirp/slirp.h | 2 ++ > 7 files changed, 33 insertions(+), 15 deletions(-) > > diff --git a/include/net/net.h b/include/net/net.h > index 643295d163..075cc01267 100644 > --- a/include/net/net.h > +++ b/include/net/net.h > @@ -146,7 +146,7 @@ ssize_t qemu_sendv_packet(NetClientState *nc, const > struct iovec *iov, > int iovcnt); > ssize_t qemu_sendv_packet_async(NetClientState *nc, const struct iovec *iov, > int iovcnt, NetPacketSent *sent_cb); > -void qemu_send_packet(NetClientState *nc, const uint8_t *buf, int size); > +ssize_t qemu_send_packet(NetClientState *nc, const uint8_t *buf, int size); > ssize_t qemu_send_packet_raw(NetClientState *nc, const uint8_t *buf, int > size); > ssize_t qemu_send_packet_async(NetClientState *nc, const uint8_t *buf, > int size, NetPacketSent *sent_cb); > diff --git a/net/net.c b/net/net.c > index 3acbdccd61..5dcff7fe2a 100644 > --- a/net/net.c > +++ b/net/net.c > @@ -668,9 +668,9 @@ ssize_t qemu_send_packet_async(NetClientState *sender, > buf, size, sent_cb); > } > > -void qemu_send_packet(NetClientState *nc, const uint8_t *buf, int size) > +ssize_t qemu_send_packet(NetClientState *nc, const uint8_t *buf, int size) > { > - qemu_send_packet_async(nc, buf, size, NULL); > + return qemu_send_packet_async(nc, buf, size, NULL); > } > > ssize_t qemu_send_packet_raw(NetClientState *nc, const uint8_t *buf, int > size) > diff --git a/net/slirp.c b/net/slirp.c > index 7b4f9f5c5e..664ff1c002 100644 > --- a/net/slirp.c > +++ b/net/slirp.c > @@ -108,11 +108,12 @@ static void slirp_smb_cleanup(SlirpState *s); > static inline void slirp_smb_cleanup(SlirpState *s) { } > #endif > > -static void net_slirp_output(void *opaque, const uint8_t *pkt, int pkt_len) > +static ssize_t net_slirp_send_packet(const void *pkt, size_t pkt_len, > + void *opaque) > { > SlirpState *s = opaque; > > - qemu_send_packet(&s->nc, pkt, pkt_len); > + return qemu_send_packet(&s->nc, pkt, pkt_len); > } > > static ssize_t net_slirp_receive(NetClientState *nc, const uint8_t *buf, > size_t size) > @@ -197,7 +198,7 @@ static void net_slirp_unregister_poll_fd(int fd) > } > > static const SlirpCb slirp_cb = { > - .output = net_slirp_output, > + .send_packet = net_slirp_send_packet, > .guest_error = net_slirp_guest_error, > .clock_get_ns = net_slirp_clock_get_ns, > .timer_new = net_slirp_timer_new, > @@ -780,7 +781,7 @@ static void guestfwd_read(void *opaque, const uint8_t > *buf, int size) > slirp_socket_recv(fwd->slirp, fwd->server, fwd->port, buf, size); > } > > -static int guestfwd_write(const void *buf, size_t len, void *chr) > +static ssize_t guestfwd_write(const void *buf, size_t len, void *chr) > { > return qemu_chr_fe_write_all(chr, buf, len); > } > diff --git a/slirp/libslirp.h b/slirp/libslirp.h > index 02cbec9f8b..8e5d4ed11b 100644 > --- a/slirp/libslirp.h > +++ b/slirp/libslirp.h > @@ -15,7 +15,7 @@ > > typedef struct Slirp Slirp; > > -typedef int (*SlirpWriteCb)(const void *buf, size_t len, void *opaque); > +typedef ssize_t (*SlirpWriteCb)(const void *buf, size_t len, void *opaque); > typedef void (*SlirpTimerCb)(void *opaque); > > /* > @@ -23,10 +23,13 @@ typedef void (*SlirpTimerCb)(void *opaque); > */ > typedef struct SlirpCb { > /* > - * Send an ethernet frame to the guest network. The opaque parameter > - * is the one given to slirp_init(). > + * Send an ethernet frame to the guest network. The opaque > + * parameter is the one given to slirp_init(). The function > + * doesn't need to send all the data and may return <len (no > + * buffering is done on libslirp side, so the data will be dropped > + * in this case). <0 reports an IO error. > */ > - void (*output)(void *opaque, const uint8_t *pkt, int pkt_len); > + SlirpWriteCb send_packet; > /* Print a message for an error due to guest misbehavior. */ > void (*guest_error)(const char *msg); > /* Return the virtual clock value in nanoseconds */ > diff --git a/slirp/ncsi.c b/slirp/ncsi.c > index 327f17543c..359f52c284 100644 > --- a/slirp/ncsi.c > +++ b/slirp/ncsi.c > @@ -162,5 +162,5 @@ void ncsi_input(Slirp *slirp, const uint8_t *pkt, int > pkt_len) > *pchecksum = htonl(checksum); > ncsi_rsp_len += 4; > > - slirp->cb->output(slirp->opaque, ncsi_reply, ETH_HLEN + ncsi_rsp_len); > + slirp_send_packet_all(slirp, ncsi_reply, ETH_HLEN + ncsi_rsp_len); > } > diff --git a/slirp/slirp.c b/slirp/slirp.c > index 3304c83001..2bc53e3e12 100644 > --- a/slirp/slirp.c > +++ b/slirp/slirp.c > @@ -800,7 +800,7 @@ static void arp_input(Slirp *slirp, const uint8_t *pkt, > int pkt_len) > rah->ar_sip = ah->ar_tip; > memcpy(rah->ar_tha, ah->ar_sha, ETH_ALEN); > rah->ar_tip = ah->ar_sip; > - slirp->cb->output(slirp->opaque, arp_reply, sizeof(arp_reply)); > + slirp_send_packet_all(slirp, arp_reply, sizeof(arp_reply)); > } > break; > case ARPOP_REPLY: > @@ -900,7 +900,7 @@ static int if_encap4(Slirp *slirp, struct mbuf *ifm, > struct ethhdr *eh, > /* target IP */ > rah->ar_tip = iph->ip_dst.s_addr; > slirp->client_ipaddr = iph->ip_dst; > - slirp->cb->output(slirp->opaque, arp_req, sizeof(arp_req)); > + slirp_send_packet_all(slirp, arp_req, sizeof(arp_req)); > ifm->resolution_requested = true; > > /* Expire request and drop outgoing packet after 1 second */ > @@ -985,7 +985,7 @@ int if_encap(Slirp *slirp, struct mbuf *ifm) > eh->h_dest[0], eh->h_dest[1], eh->h_dest[2], > eh->h_dest[3], eh->h_dest[4], eh->h_dest[5]); > memcpy(buf + sizeof(struct ethhdr), ifm->m_data, ifm->m_len); > - slirp->cb->output(slirp->opaque, buf, ifm->m_len + ETH_HLEN); > + slirp_send_packet_all(slirp, buf, ifm->m_len + ETH_HLEN); > return 1; > } > > @@ -1152,3 +1152,15 @@ void slirp_socket_recv(Slirp *slirp, struct in_addr > guest_addr, int guest_port, > if (ret > 0) > tcp_output(sototcpcb(so)); > } > + > +void slirp_send_packet_all(Slirp *slirp, const void *buf, size_t len) > +{ > + ssize_t ret = slirp->cb->send_packet(buf, len, slirp->opaque); > + > + if (ret < 0) { > + g_critical("Failed to send packet, ret: %ld", (long) ret);
>From the v3 discussion [*] I thought send_packet() would return a gssize, then we'd use G_GSSIZE_FORMAT here (and similarly use gssize instead ssize_t in this series). Anyway your fix is simpler. And we can still do this on top of this PR. [*] https://lists.gnu.org/archive/html/qemu-devel/2019-02/msg01841.html > + } else if (ret < len) { > + DEBUG_ERROR("send_packet() didn't send all data: %ld < %lu", > + (long) ret, (unsigned long) len); > + } > +} > diff --git a/slirp/slirp.h b/slirp/slirp.h > index 05b8364c07..752a4cd8c8 100644 > --- a/slirp/slirp.h > +++ b/slirp/slirp.h > @@ -269,4 +269,6 @@ struct tcpcb *tcp_drop(struct tcpcb *tp, int err); > struct socket * > slirp_find_ctl_socket(Slirp *slirp, struct in_addr guest_addr, int > guest_port); > > +void slirp_send_packet_all(Slirp *slirp, const void *buf, size_t len); > + > #endif >