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debugnet(4): Infer non-server connection parameters

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Loosen requirements for connecting to debugnet-type servers.  Only require a
destination address; the rest can theoretically be inferred from the routing
table.

Relax corresponding constraints in netdump(4) and move ifp validation to
debugnet connection time.

Submitted by:	John Reimer <john.reimer AT emc.com> (earlier version)
Reviewed by:	markj
Differential Revision:	https://reviews.freebsd.org/D21482
This commit is contained in:
Conrad Meyer 2019-10-17 20:10:32 +00:00
parent 757dbc72ef
commit fde2cf65ce
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=353694
5 changed files with 141 additions and 63 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
share/man/man4/ddb.4
View File

@ -1192,7 +1192,7 @@ In remote GDB mode, another machine is required that runs
using the remote debug feature, with a connection to the serial
console port on the target machine.
.Pp
.It Ic netdump Fl s Ar server Oo Fl g Ar gateway Oc Fl c Ar client Fl i Ar iface
.It Ic netdump Fl s Ar server Oo Fl g Ar gateway Fl c Ar client Fl i Ar iface Oc
Configure
.Xr netdump 4
with the provided parameters, and immediately perform a netdump.

113
sys/net/debugnet.c
View File

@ -491,8 +491,12 @@ debugnet_free(struct debugnet_pcb *pcb)
MPASS(pcb == &g_dnet_pcb);
ifp = pcb->dp_ifp;
ifp->if_input = pcb->dp_drv_input;
ifp->if_debugnet_methods->dn_event(ifp, DEBUGNET_END);
if (ifp != NULL) {
if (pcb->dp_drv_input != NULL)
ifp->if_input = pcb->dp_drv_input;
if (pcb->dp_event_started)
ifp->if_debugnet_methods->dn_event(ifp, DEBUGNET_END);
}
debugnet_mbuf_finish();
g_debugnet_pcb_inuse = false;
@ -527,8 +531,87 @@ debugnet_connect(const struct debugnet_conn_params *dcp,
/* Switch to the debugnet mbuf zones. */
debugnet_mbuf_start();
/* At least one needed parameter is missing; infer it. */
if (pcb->dp_client == INADDR_ANY || pcb->dp_gateway == INADDR_ANY ||
pcb->dp_ifp == NULL) {
struct sockaddr_in dest_sin, *gw_sin, *local_sin;
struct rtentry *dest_rt;
struct ifnet *rt_ifp;
memset(&dest_sin, 0, sizeof(dest_sin));
dest_sin = (struct sockaddr_in) {
.sin_len = sizeof(dest_sin),
.sin_family = AF_INET,
.sin_addr.s_addr = pcb->dp_server,
};
CURVNET_SET(vnet0);
dest_rt = rtalloc1((struct sockaddr *)&dest_sin, 0,
RTF_RNH_LOCKED);
CURVNET_RESTORE();
if (dest_rt == NULL) {
db_printf("%s: Could not get route for that server.\n",
__func__);
error = ENOENT;
goto cleanup;
}
if (dest_rt->rt_gateway->sa_family == AF_INET)
gw_sin = (struct sockaddr_in *)dest_rt->rt_gateway;
else {
if (dest_rt->rt_gateway->sa_family == AF_LINK)
DNETDEBUG("Destination address is on link.\n");
gw_sin = NULL;
}
MPASS(dest_rt->rt_ifa->ifa_addr->sa_family == AF_INET);
local_sin = (struct sockaddr_in *)dest_rt->rt_ifa->ifa_addr;
rt_ifp = dest_rt->rt_ifp;
if (pcb->dp_client == INADDR_ANY)
pcb->dp_client = local_sin->sin_addr.s_addr;
if (pcb->dp_gateway == INADDR_ANY && gw_sin != NULL)
pcb->dp_gateway = gw_sin->sin_addr.s_addr;
if (pcb->dp_ifp == NULL)
pcb->dp_ifp = rt_ifp;
RTFREE_LOCKED(dest_rt);
}
ifp = pcb->dp_ifp;
if (debugnet_debug > 0) {
char serbuf[INET_ADDRSTRLEN], clibuf[INET_ADDRSTRLEN],
gwbuf[INET_ADDRSTRLEN];
inet_ntop(AF_INET, &pcb->dp_server, serbuf, sizeof(serbuf));
inet_ntop(AF_INET, &pcb->dp_client, clibuf, sizeof(clibuf));
if (pcb->dp_gateway != INADDR_ANY)
inet_ntop(AF_INET, &pcb->dp_gateway, gwbuf, sizeof(gwbuf));
DNETDEBUG("Connecting to %s:%d%s%s from %s:%d on %s\n",
serbuf, pcb->dp_server_port,
(pcb->dp_gateway == INADDR_ANY) ? "" : " via ",
(pcb->dp_gateway == INADDR_ANY) ? "" : gwbuf,
clibuf, pcb->dp_client_ack_port, if_name(ifp));
}
/* Validate iface is online and supported. */
if (!DEBUGNET_SUPPORTED_NIC(ifp)) {
printf("%s: interface '%s' does not support debugnet\n",
__func__, if_name(ifp));
error = ENODEV;
goto cleanup;
}
if ((if_getflags(ifp) & IFF_UP) == 0) {
printf("%s: interface '%s' link is down\n", __func__,
if_name(ifp));
error = ENXIO;
goto cleanup;
}
ifp->if_debugnet_methods->dn_event(ifp, DEBUGNET_START);
pcb->dp_event_started = true;
/*
* We maintain the invariant that g_debugnet_pcb_inuse is always true
@ -842,37 +925,21 @@ debugnet_parse_ddb_cmd(const char *cmd, struct debugnet_ddb_config *result)
t = db_read_token_flags(DRT_WSPACE);
}
/* Currently, all three are required. */
if (!opt_client.has_opt || !opt_server.has_opt || ifp == NULL) {
db_printf("%s needs all of client, server, and interface "
"specified.\n", cmd);
if (!opt_server.has_opt) {
db_printf("%s: need a destination server address\n", cmd);
goto usage;
}
result->dd_has_client = opt_client.has_opt;
result->dd_has_gateway = opt_gateway.has_opt;
/* Iface validation stolen from netdump_configure. */
if (!DEBUGNET_SUPPORTED_NIC(ifp)) {
db_printf("%s: interface '%s' does not support debugnet\n",
cmd, if_name(ifp));
error = ENODEV;
goto cleanup;
}
if ((if_getflags(ifp) & IFF_UP) == 0) {
db_printf("%s: interface '%s' link is down\n", cmd,
if_name(ifp));
error = ENXIO;
goto cleanup;
}
result->dd_ifp = ifp;
/* We parsed the full line to tEOL already, or bailed with an error. */
return (0);
usage:
db_printf("Usage: %s -s <server> [-g <gateway>] -c <localip> "
"-i <interface>\n", cmd);
db_printf("Usage: %s -s <server> [-g <gateway> -c <localip> "
"-i <interface>]\n", cmd);
error = EINVAL;
/* FALLTHROUGH */
cleanup:

6
sys/net/debugnet.h
View File

@ -176,11 +176,12 @@ void debugnet_any_ifnet_update(struct ifnet *);
/*
* DDB parsing helper for common debugnet options.
*
* -s <server> [-g <gateway] -c <localip> -i <interface>
* -s <server> [-g <gateway -c <localip> -i <interface>]
*
* Order is not significant. Interface is an online interface that supports
* debugnet and can route to the debugnet server. The other parameters are all
* IP addresses. For now, all parameters are mandatory, except gateway.
* IP addresses. Only the server parameter is required. The others are
* inferred automatically from the routing table, if not explicitly provided.
*
* Provides basic '-h' using provided 'cmd' string.
*
@ -191,6 +192,7 @@ struct debugnet_ddb_config {
in_addr_t dd_client;
in_addr_t dd_server;
in_addr_t dd_gateway;
bool dd_has_client : 1;
bool dd_has_gateway : 1;
};
int debugnet_parse_ddb_cmd(const char *cmd,

1
sys/net/debugnet_int.h
View File

@ -69,6 +69,7 @@ struct debugnet_pcb {
enum dnet_pcb_st dp_state;
uint16_t dp_client_ack_port;
bool dp_event_started;
};
/* TODO(CEM): Obviate this assertion by using a BITSET(9) for acks. */

82
sys/netinet/netdump/netdump_client.c
View File

@ -138,8 +138,8 @@ static int nd_debug;
SYSCTL_INT(_net_netdump, OID_AUTO, debug, CTLFLAG_RWTUN,
&nd_debug, 0,
"Debug message verbosity");
SYSCTL_PROC(_net_netdump, OID_AUTO, enabled, CTLFLAG_RD | CTLTYPE_INT,
&nd_ifp, 0, netdump_enabled_sysctl, "I", "netdump configuration status");
SYSCTL_PROC(_net_netdump, OID_AUTO, enabled, CTLFLAG_RD | CTLTYPE_INT, NULL, 0,
netdump_enabled_sysctl, "I", "netdump configuration status");
static char nd_path[MAXPATHLEN];
SYSCTL_STRING(_net_netdump, OID_AUTO, path, CTLFLAG_RW,
nd_path, sizeof(nd_path),
@ -158,12 +158,21 @@ SYSCTL_INT(_net_netdump, OID_AUTO, arp_retries, CTLFLAG_RWTUN,
&debugnet_arp_nretries, 0,
"Number of ARP attempts before giving up");
static bool nd_is_enabled;
static bool
netdump_enabled(void)
{
NETDUMP_ASSERT_LOCKED();
return (nd_ifp != NULL);
return (nd_is_enabled);
}
static void
netdump_set_enabled(bool status)
{
NETDUMP_ASSERT_LOCKED();
nd_is_enabled = status;
}
static int
@ -296,10 +305,6 @@ netdump_start(struct dumperinfo *di)
printf("netdump_start: can't netdump; no server IP given\n");
return (EINVAL);
}
if (nd_client.s_addr == INADDR_ANY) {
printf("netdump_start: can't netdump; no client IP given\n");
return (EINVAL);
}
/* We start dumping at offset 0. */
di->dumpoff = 0;
@ -369,14 +374,16 @@ netdump_unconfigure(void)
struct diocskerneldump_arg kda;
NETDUMP_ASSERT_WLOCKED();
KASSERT(netdump_enabled(), ("%s: nd_ifp NULL", __func__));
KASSERT(netdump_enabled(), ("%s: not enabled", __func__));
bzero(&kda, sizeof(kda));
kda.kda_index = KDA_REMOVE_DEV;
(void)dumper_remove(nd_conf.ndc_iface, &kda);
if_rele(nd_ifp);
if (nd_ifp != NULL)
if_rele(nd_ifp);
nd_ifp = NULL;
netdump_set_enabled(false);
log(LOG_WARNING, "netdump: Lost configured interface %s\n",
nd_conf.ndc_iface);
@ -406,32 +413,25 @@ netdump_configure(struct diocskerneldump_arg *conf, struct thread *td)
NETDUMP_ASSERT_WLOCKED();
if (td != NULL)
vnet = TD_TO_VNET(td);
else
vnet = vnet0;
CURVNET_SET(vnet);
if (td != NULL && !IS_DEFAULT_VNET(curvnet)) {
if (conf->kda_iface[0] != 0) {
if (td != NULL)
vnet = TD_TO_VNET(td);
else
vnet = vnet0;
CURVNET_SET(vnet);
if (td != NULL && !IS_DEFAULT_VNET(curvnet)) {
CURVNET_RESTORE();
return (EINVAL);
}
ifp = ifunit_ref(conf->kda_iface);
CURVNET_RESTORE();
return (EINVAL);
}
ifp = ifunit_ref(conf->kda_iface);
CURVNET_RESTORE();
} else
ifp = NULL;
if (ifp == NULL)
return (ENOENT);
if ((if_getflags(ifp) & IFF_UP) == 0) {
if_rele(ifp);
return (ENXIO);
}
if (!DEBUGNET_SUPPORTED_NIC(ifp)) {
if_rele(ifp);
return (ENODEV);
}
if (netdump_enabled())
if (nd_ifp != NULL)
if_rele(nd_ifp);
nd_ifp = ifp;
netdump_set_enabled(true);
#define COPY_SIZED(elm) do { \
_Static_assert(sizeof(nd_conf.ndc_ ## elm) == \
@ -527,8 +527,9 @@ netdump_ioctl(struct cdev *dev __unused, u_long cmd, caddr_t addr,
break;
}
strlcpy(conf12->ndc12_iface, nd_ifp->if_xname,
sizeof(conf12->ndc12_iface));
if (nd_ifp != NULL)
strlcpy(conf12->ndc12_iface, nd_ifp->if_xname,
sizeof(conf12->ndc12_iface));
memcpy(&conf12->ndc12_server, &nd_server,
sizeof(conf12->ndc12_server));
memcpy(&conf12->ndc12_client, &nd_client,
@ -549,8 +550,9 @@ netdump_ioctl(struct cdev *dev __unused, u_long cmd, caddr_t addr,
break;
}
strlcpy(conf->kda_iface, nd_ifp->if_xname,
sizeof(conf->kda_iface));
if (nd_ifp != NULL)
strlcpy(conf->kda_iface, nd_ifp->if_xname,
sizeof(conf->kda_iface));
memcpy(&conf->kda_server, &nd_server, sizeof(nd_server));
memcpy(&conf->kda_client, &nd_client, sizeof(nd_client));
memcpy(&conf->kda_gateway, &nd_gateway, sizeof(nd_gateway));
@ -776,11 +778,17 @@ DB_FUNC(netdump, db_netdump_cmd, db_cmd_table, CS_OWN, NULL)
/* Translate to a netdump dumper config. */
memset(&conf, 0, sizeof(conf));
strlcpy(conf.kda_iface, if_name(params.dd_ifp), sizeof(conf.kda_iface));
if (params.dd_ifp != NULL)
strlcpy(conf.kda_iface, if_name(params.dd_ifp),
sizeof(conf.kda_iface));
conf.kda_af = AF_INET;
conf.kda_server.in4 = (struct in_addr) { params.dd_server };
conf.kda_client.in4 = (struct in_addr) { params.dd_client };
if (params.dd_has_client)
conf.kda_client.in4 = (struct in_addr) { params.dd_client };
else
conf.kda_client.in4 = (struct in_addr) { INADDR_ANY };
if (params.dd_has_gateway)
conf.kda_gateway.in4 = (struct in_addr) { params.dd_gateway };
else