Commit 4faf9634 authored by Grégoire Henry's avatar Grégoire Henry

Factorisation de code et gestion des erreurs.

  - Fusion de kernel_listen dans kernel_read.
  - Fusion de monitor_kernel_routes dans filter_kernel_routes.
  - En cas d'erreur d'entree/sortie on ferme les sockets.
    - nl_command est rouverte au besoin
    - nl_listen doit etre rouverte a l'aide de kernel_setup_socket(1)
parent ec19de91
......@@ -427,6 +427,7 @@ main(int argc, char **argv)
if(timeval_compare(&tv, &now) > 0) {
timeval_minus(&tv, &tv, &now);
FD_SET(protocol_socket, &readfds);
if(kernel_socket < 0) kernel_setup_socket(1);
if(kernel_socket >= 0)
FD_SET(kernel_socket, &readfds);
rc = select(MAX(protocol_socket, kernel_socket) + 1,
......
......@@ -46,7 +46,6 @@ THE SOFTWARE.
static int old_forwarding = -1;
static int old_accept_redirects = -1;
static int ifindex_lo = -1;
static int
read_proc(char *filename)
......@@ -104,6 +103,7 @@ struct netlink {
static struct netlink nl_command = { 0, -1, {0}, 0 };
static struct netlink nl_listen = { 0, -1, {0}, 0 };
static int nl_setup = 0;
static int
netlink_socket(struct netlink *nl, uint32_t groups)
......@@ -150,21 +150,32 @@ netlink_socket(struct netlink *nl, uint32_t groups)
}
static int
netlink_read(int (*filter)(struct nlmsghdr *, void *data), void *data)
netlink_read(struct netlink *nl, struct netlink *nl_ignore, int answer,
int (*fn)(struct nlmsghdr *nh, void *data), void *data)
{
struct sockaddr_nl nladdr;
/* 'answer' must be true when we just have send a request on 'nl_socket' */
/* 'nl_ignore' is used in kernel_callback to ignore message originating */
/* from 'nl_command' while reading 'nl_listen' */
/* Return code : */
/* -1 : error */
/* 0 : if(fn) found_interesting; else found_ack; */
/* 1 : only if(fn) nothing interesting has been found */
/* 2 : nothing found, retry */
int err;
struct msghdr msg;
struct sockaddr_nl nladdr;
struct iovec iov;
struct nlmsghdr *nh;
int len;
int interesting = 0;
int done = 0;
char buf[8192];
if(nl_command.sock < 0) {
fprintf(stderr,"netlink_read: netlink not initialized.\n");
return -1;
}
memset(&nladdr, 0, sizeof(nladdr));
nladdr.nl_family = AF_NETLINK;
......@@ -176,84 +187,95 @@ netlink_read(int (*filter)(struct nlmsghdr *, void *data), void *data)
iov.iov_base = &buf;
while(1) {
int i = 0;
do {
iov.iov_len = sizeof(buf);
len = recvmsg(nl_command.sock, &msg, 0);
len = recvmsg(nl->sock, &msg, 0);
if(len < 0 && (errno == EAGAIN || errno == EINTR)) {
int rc;
rc = wait_for_fd(0, nl_command.sock, 100);
rc = wait_for_fd(0, nl->sock, 100);
if(rc <= 0) {
if(rc == 0)
errno = EAGAIN;
} else {
len = recvmsg(nl_command.sock, &msg, 0);
len = recvmsg(nl->sock, &msg, 0);
}
}
if(len < 0) {
perror("recvmsg(nl_command)");
continue;
perror("netlink_read: recvmsg()");
return 2;
} else if(len == 0) {
fprintf(stderr, "EOF on netlink\n");
errno = EIO;
return -1;
} else if(msg.msg_namelen != nl_command.socklen) {
fprintf(stderr, "sender address length == %d\n", msg.msg_namelen);
errno = EIO;
return -1;
fprintf(stderr, "netlink_read: EOF\n");
goto socket_error;
} else if(msg.msg_namelen != nl->socklen) {
fprintf(stderr,
"netlink_read: unexpected sender address length (%d)\n",
msg.msg_namelen);
goto socket_error;
} else if(nladdr.nl_pid != 0) {
debugf("Netlink message not for us.\n");
continue;
debugf("netlink_read: message not sent by kernel.\n");
return 2;
}
debugf("Netlink message: ");
for(nh = (struct nlmsghdr *)buf;
NLMSG_OK(nh, len);
nh = NLMSG_NEXT(nh, len)) {
debugf("%d %s", i,
(nh->nlmsg_flags & NLM_F_MULTI) ? "(multi) " : "");
i++;
if(nh->nlmsg_pid != nl_command.sockaddr.nl_pid ||
nh->nlmsg_seq != nl_command.seqno) {
debugf("(wrong seqno/pid), ");
NLMSG_OK(nh, len);
nh = NLMSG_NEXT(nh, len)) {
debugf("%s", (nh->nlmsg_flags & NLM_F_MULTI) ? "[multi] " : "");
if(!(nh->nlmsg_flags & NLM_F_MULTI))
done = 1;
if(nl_ignore && nh->nlmsg_pid == nl_ignore->sockaddr.nl_pid) {
debugf("(ignore), ");
continue;
} else if(answer && (nh->nlmsg_pid != nl->sockaddr.nl_pid ||
nh->nlmsg_seq != nl->seqno)) {
debugf("(wrong seqno %d %d /pid %d %d), ",
nh->nlmsg_seq, nl->seqno,
nh->nlmsg_pid, nl->sockaddr.nl_pid);
continue;
} else if(nh->nlmsg_type == NLMSG_DONE) {
debugf("(done)\n");
goto done;
done = 1;
break;
} else if(nh->nlmsg_type == NLMSG_ERROR) {
struct nlmsgerr *err = (struct nlmsgerr *)NLMSG_DATA(nh);
if(err->error == 0) {
debugf("ACK\n");
if(!(nh->nlmsg_flags & NLM_F_MULTI))
debugf("(ACK)\n");
if(!(nh->nlmsg_flags & NLM_F_MULTI) && !fn)
return 0;
continue;
} else {
errno = -err->error;
perror("netlink_read");
errno = -err->error;
return -1;
}
errno = -err->error;
perror("netlink_read");
errno = -err->error;
return -1;
} else if(fn) {
debugf("(msg -> \"");
err = fn(nh,data);
debugf("\" %d), ", err);
if(err < 0) return err;
interesting = interesting || err;
continue;
}
if(filter)
filter(nh, data);
if(!(nh->nlmsg_flags & NLM_F_MULTI))
break;
debugf(", ");
}
debugf("\n");
if(msg.msg_flags & MSG_TRUNC) {
fprintf(stderr, "Netlink message truncated\n");
continue;
}
}
if(msg.msg_flags & MSG_TRUNC)
fprintf(stderr, "netlink_read: message truncated\n");
done:
return 0;
}
} while (!done);
return interesting;
socket_error:
close(nl->sock);
nl->sock = -1;
errno = EIO;
return -1;
}
static int
netlink_talk(struct nlmsghdr *nh)
......@@ -264,11 +286,6 @@ netlink_talk(struct nlmsghdr *nh)
struct msghdr msg;
struct iovec iov;
if(nl_command.sock < 0) {
fprintf(stderr,"netlink_talk: netlink not initialized.\n");
return -1;
}
memset(&nladdr, 0, sizeof(nladdr));
nladdr.nl_family = AF_NETLINK;
nladdr.nl_pid = 0;
......@@ -303,7 +320,9 @@ netlink_talk(struct nlmsghdr *nh)
return -1;
}
return netlink_read(NULL,NULL); /* ACK */
rc = netlink_read(&nl_command, NULL, 1, NULL, NULL); /* ACK */
return rc;
}
static int
......@@ -318,12 +337,6 @@ netlink_send_dump(int type, void *data, int len) {
} buf;
int rc;
if(nl_command.sock < 0) {
fprintf(stderr,"netlink_send_dump: netlink not initialized.\n");
errno = EIO;
return -1;
}
/* At least we should send an 'struct rtgenmsg' */
if(data == NULL || len == 0) {
errno = EIO;
......@@ -365,87 +378,6 @@ netlink_send_dump(int type, void *data, int len) {
return 0;
}
static int
netlink_listen(int (*monitor)(struct nlmsghdr *nh, void *data), void *data) {
int err;
struct msghdr msg;
struct sockaddr_nl nladdr;
struct iovec iov;
struct nlmsghdr *nh;
int len;
int interesting = 0;
char buf[8192];
if(nl_listen.sock < 0) {
fprintf(stderr,"netlink_listen: netlink not initialized.\n");
errno = EIO;
return -1;
}
memset(&msg, 0, sizeof(msg));
msg.msg_name = &nladdr;
msg.msg_namelen = sizeof(nladdr);
msg.msg_iov = &iov;
msg.msg_iovlen = 1;
memset(&nladdr, 0, sizeof(nladdr));
nladdr.nl_family = AF_NETLINK;
iov.iov_base = buf;
iov.iov_len = sizeof(buf);
len = recvmsg(nl_listen.sock, &msg, 0);
if(len < 0) {
int saved_errno = errno;
if(errno == EINTR || errno == EAGAIN)
return 0;
perror("recvmsg(netlink)");
errno = saved_errno;
return -1;
}
if(len == 0) {
fprintf(stderr, "recvmsg(netlink): EOF\n");
errno = EIO;
return -1;
}
if(msg.msg_namelen != nl_listen.socklen) {
fprintf(stderr,
"netlink_listen: unexpected sender address length (%d)\n",
msg.msg_namelen);
errno = EIO;
return -1;
}
for(nh = (struct nlmsghdr *)buf;
NLMSG_OK(nh, len);
nh = NLMSG_NEXT(nh, len)) {
if(nh->nlmsg_type == NLMSG_DONE) {
continue;
} else if(nh->nlmsg_type == NLMSG_ERROR) {
continue;
}
if(nh->nlmsg_pid == nl_command.sockaddr.nl_pid)
continue;
if(monitor) {
err = monitor(nh,data);
if(err < 0) return err;
interesting = interesting || err;
}
}
if(msg.msg_flags & MSG_TRUNC) {
fprintf(stderr, "Netlink message truncated\n");
}
return interesting;
}
int
kernel_setup(int setup)
{
......@@ -482,6 +414,7 @@ kernel_setup(int setup)
perror("Couldn't write accept_redirects knob.");
return -1;
}
nl_setup = 1;
return 1;
} else {
if(old_forwarding >= 0) {
......@@ -504,6 +437,7 @@ kernel_setup(int setup)
close(nl_command.sock);
nl_command.sock = -1;
nl_setup = 0;
return 1;
}
......@@ -607,7 +541,23 @@ kernel_route(int operation, const unsigned char *dest, unsigned short plen,
int len = sizeof(buf.raw);
int rc;
if(operation == ROUTE_MODIFY) {
if(!nl_setup) {
fprintf(stderr,"kernel_route: netlink not initialized.\n");
errno = EIO;
return -1;
}
/* if the socket has been closed after an IO error, */
/* we try to re-open it. */
if(nl_command.sock < 0) {
rc = netlink_socket(&nl_command, 0);
if(rc < 0) {
perror("kernel_route: netlink_socket()");
return -1;
}
}
if(operation == ROUTE_MODIFY) {
if(newmetric == metric && memcmp(newgate, gate, 16) == 0 &&
newifindex == ifindex)
return 0;
......@@ -632,12 +582,6 @@ kernel_route(int operation, const unsigned char *dest, unsigned short plen,
if(metric >= KERNEL_INFINITY && plen == 0)
return 0;
if(ifindex_lo < 0) {
ifindex_lo = if_nametoindex("lo");
if(ifindex_lo <= 0)
return -1;
}
memset(buf.raw, 0, sizeof(buf.raw));
if(operation == ROUTE_ADD) {
buf.nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_CREATE | NLM_F_EXCL;
......@@ -695,8 +639,8 @@ parse_kernel_route_rta(struct rtmsg *rtm, int len, struct kernel_route *route)
struct rtattr *rta= RTM_RTA(rtm);;
len -= NLMSG_ALIGN(sizeof(*rtm));
memset(&route->prefix,0,sizeof(struct in6_addr));
memset(&route->gw,0,sizeof(struct in6_addr));
memset(&route->prefix, 0, sizeof(struct in6_addr));
memset(&route->gw, 0, sizeof(struct in6_addr));
route->plen = rtm->rtm_dst_len;
route->metric = KERNEL_INFINITY;
route->ifindex = 0;
......@@ -704,10 +648,10 @@ parse_kernel_route_rta(struct rtmsg *rtm, int len, struct kernel_route *route)
while(RTA_OK(rta, len)) {
switch (rta->rta_type) {
case RTA_DST:
memcpy(&route->prefix,RTA_DATA(rta),16);
memcpy(&route->prefix, RTA_DATA(rta), 16);
break;
case RTA_GATEWAY:
memcpy(&route->gw,RTA_DATA(rta),16);
memcpy(&route->gw, RTA_DATA(rta), 16);
break;
case RTA_OIF:
route->ifindex = *(int*)RTA_DATA(rta);
......@@ -750,58 +694,42 @@ print_kernel_route(int add, int protocol, int type,
}
debugf("%s kernel route: dest: %s/%d gw: %s metric: %d if: %s "
"(proto: %d, type: %d)\n",
"(proto: %d, type: %d)",
add == RTM_NEWROUTE ? "Add" : "Delete",
addr_prefix, route->plen, addr_gw, route->metric, ifname,
protocol, type);
}
static int
monitor_kernel_route(struct nlmsghdr *nh, void *data)
filter_kernel_routes(struct nlmsghdr *nh, void *data)
{
int rc;
struct kernel_route route;
int len = nh->nlmsg_len;
struct rtmsg *rtm;
if(nh->nlmsg_type != RTM_NEWROUTE && nh->nlmsg_type != RTM_DELROUTE)
return 0;
struct kernel_route *current_route;
struct kernel_route route;
rtm = (struct rtmsg*)NLMSG_DATA(nh);
len -= NLMSG_LENGTH(0);
int maxplen = 128;
int maxroutes = 0;
struct kernel_route *routes = NULL;
int *found = NULL;
if(rtm->rtm_protocol == RTPROT_BOOT || rtm->rtm_protocol == RTPROT_BABEL)
return 0;
struct rtmsg *rtm;
if(debug >= 2) {
rc = parse_kernel_route_rta(rtm, len, &route);
if(rc >= 0)
print_kernel_route(nh->nlmsg_type, rtm->rtm_protocol,
rtm->rtm_type, &route);
if(data) {
void **args = (void**)data;
maxplen = *(int*)args[0];
maxroutes = *(int*)args[1];
routes = (struct kernel_route *)args[2];
found = (int*)args[3];
}
return 1;
}
static int
filter_kernel_routes(struct nlmsghdr *nh, void *data)
{
int rc;
void **args = (void**)data;
int maxplen = *(int*)args[0];
int maxroutes = *(int*)args[1];
struct kernel_route *routes = (struct kernel_route *)args[2];
int *found = (int*)args[3];
struct rtmsg *rtm;
int len = nh->nlmsg_len;
if(*found >= maxroutes)
if(data && *found >= maxroutes)
return 0;
if(nh->nlmsg_type != RTM_NEWROUTE)
if(nh->nlmsg_type != RTM_NEWROUTE &&
(data || nh->nlmsg_type != RTM_DELROUTE))
return 0;
rtm = (struct rtmsg*)NLMSG_DATA(nh);
......@@ -819,15 +747,27 @@ filter_kernel_routes(struct nlmsghdr *nh, void *data)
if(rtm->rtm_table != RT_TABLE_MAIN)
return 0;
rc = parse_kernel_route_rta(rtm, len, &routes[*found]);
if(data)
current_route = &routes[*found];
else
current_route = &route;
rc = parse_kernel_route_rta(rtm, len, current_route);
if(rc < 0)
return 0;
if(rtm->rtm_dst_len >= 8 &&
(routes[*found].prefix[0] == 0xFF || routes[*found].prefix[0] == 0))
return 0;
(current_route->prefix[0] == 0xFF || current_route->prefix[0] == 0))
return 0;
if(debug >= 2) {
if(rc >= 0) {
print_kernel_route(nh->nlmsg_type, rtm->rtm_protocol,
rtm->rtm_type, current_route);
}
}
*found = (*found)+1;
if (data) *found = (*found)+1;
return 1;
......@@ -844,13 +784,29 @@ kernel_routes(int maxplen, struct kernel_route *routes, int maxroutes)
void *data[4] = { &maxp, &maxr, routes, &found };
struct rtgenmsg g;
if(!nl_setup) {
fprintf(stderr,"kernel_routes: netlink not initialized.\n");
errno = EIO;
return -1;
}
if(nl_command.sock < 0) {
rc = netlink_socket(&nl_command, 0);
if(rc < 0) {
perror("kernel_routes: netlink_socket()");
return -1;
}
}
memset(&g, 0, sizeof(g));
g.rtgen_family = AF_INET6;
rc = netlink_send_dump(RTM_GETROUTE, &g, sizeof(g));
if(rc < 0)
return -1;
rc = netlink_read(filter_kernel_routes, (void*)data);
rc = netlink_read(&nl_command, NULL, 1,
filter_kernel_routes, (void *)data);
if(rc < 0)
return -1;
......@@ -862,10 +818,22 @@ kernel_callback(int (*fn)(void*), void *closure)
{
int rc;
if(nl_listen.sock < 0)
return -1;
debugf("\nReceived changes in kernel tables.\n");
if(nl_listen.sock < 0) {
rc = kernel_setup_socket(1);
if(rc < 0) {
perror("kernel_callback: kernel_setup_socket(1)");
return -1;
}
}
rc = netlink_read(&nl_listen, &nl_command, 0, filter_kernel_routes, NULL);
if(rc < 0 && nl_listen.sock < 0)
kernel_setup_socket(1);
rc = netlink_listen(monitor_kernel_route, NULL);
/* if netlink return 0 (found something interesting) */
/* or -1 (i.e. IO error), we call... back ! */
if(rc)
return fn(closure);
......
......@@ -56,7 +56,7 @@ check_xroutes()
int i, j, n, change;
struct kernel_route routes[120];
debugf("Checking kernel routes.\n");
debugf("\nChecking kernel routes.\n");
n = -1;
for(i = 0; i < numxroutes; i++)
......
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