Merge "Move VPN routing decisions from iptables to ip" into klp-dev
diff --git a/CommandListener.cpp b/CommandListener.cpp
index 9706fe1..d6a284f 100644
--- a/CommandListener.cpp
+++ b/CommandListener.cpp
@@ -77,7 +77,6 @@
OEM_IPTABLES_FILTER_OUTPUT,
FirewallController::LOCAL_OUTPUT,
BandwidthController::LOCAL_OUTPUT,
- SecondaryTableController::LOCAL_FILTER_OUTPUT,
NULL,
};
@@ -95,7 +94,6 @@
};
static const char* MANGLE_OUTPUT[] = {
- SecondaryTableController::LOCAL_MANGLE_EXEMPT,
SecondaryTableController::LOCAL_MANGLE_OUTPUT,
NULL,
};
diff --git a/SecondaryTableController.cpp b/SecondaryTableController.cpp
index 736b5fe..5750b41 100644
--- a/SecondaryTableController.cpp
+++ b/SecondaryTableController.cpp
@@ -38,10 +38,7 @@
const char* SecondaryTableController::LOCAL_MANGLE_OUTPUT = "st_mangle_OUTPUT";
const char* SecondaryTableController::LOCAL_MANGLE_POSTROUTING = "st_mangle_POSTROUTING";
-const char* SecondaryTableController::LOCAL_MANGLE_EXEMPT = "st_mangle_EXEMPT";
-const char* SecondaryTableController::LOCAL_MANGLE_IFACE_FORMAT = "st_mangle_%s_OUTPUT";
const char* SecondaryTableController::LOCAL_NAT_POSTROUTING = "st_nat_POSTROUTING";
-const char* SecondaryTableController::LOCAL_FILTER_OUTPUT = "st_filter_OUTPUT";
SecondaryTableController::SecondaryTableController(UidMarkMap *map) : mUidMarkMap(map) {
int i;
@@ -62,15 +59,7 @@
"-F",
LOCAL_MANGLE_OUTPUT,
NULL);
- res |= execIptables(V4V6,
- "-t",
- "mangle",
- "-F",
- LOCAL_MANGLE_EXEMPT,
- NULL);
- // rule for skipping anything marked with the PROTECT_MARK
- char protect_mark_str[11];
- snprintf(protect_mark_str, sizeof(protect_mark_str), "%d", PROTECT_MARK);
+ // Do not mark sockets that have already been marked elsewhere(for example in DNS or protect).
res |= execIptables(V4V6,
"-t",
"mangle",
@@ -78,8 +67,9 @@
LOCAL_MANGLE_OUTPUT,
"-m",
"mark",
+ "!",
"--mark",
- protect_mark_str,
+ "0",
"-j",
"RETURN",
NULL);
@@ -325,7 +315,38 @@
}
snprintf(mark_str, sizeof(mark_str), "%d", mark);
- //add the catch all route to the tun. Route rules will make sure the right packets hit the table
+ // Flush any marked routes we added
+ if (!add) {
+ // iproute2 rule del will delete anything that matches, but only one rule at a time.
+ // So clearing the rules requires a bunch of calls.
+ // ip rule del will fail once there are no remaining rules that match.
+ const char *v4_cmd[] = {
+ IP_PATH,
+ "-4",
+ "rule",
+ "del",
+ "fwmark",
+ mark_str,
+ "table",
+ mark_str
+ };
+ while(!runCmd(ARRAY_SIZE(v4_cmd), v4_cmd)) {}
+
+ const char *v6_cmd[] = {
+ IP_PATH,
+ "-6",
+ "rule",
+ "del",
+ "fwmark",
+ mark_str,
+ "table",
+ mark_str
+ };
+ while(!runCmd(ARRAY_SIZE(v6_cmd), v6_cmd)) {}
+ }
+ // Add a route to the table to send all traffic to iface.
+ // We only need a default route because this table is only selected if a packet matches an
+ // IP rule that checks both the route and the mark.
const char *route_cmd[] = {
IP_PATH,
"route",
@@ -337,22 +358,10 @@
mark_str
};
ret = runCmd(ARRAY_SIZE(route_cmd), route_cmd);
+ // The command might fail during delete if the iface is gone
+ if (add && ret) return ret;
- const char *fwmark_cmd[] = {
- IP_PATH,
- "rule",
- add ? "add" : "del",
- "prio",
- RULE_PRIO,
- "fwmark",
- mark_str,
- "table",
- mark_str
- };
- ret = runCmd(ARRAY_SIZE(fwmark_cmd), fwmark_cmd);
- if (ret) return ret;
-
- //add rules for v6
+ // As above for IPv6
const char *route6_cmd[] = {
IP_PATH,
"-6",
@@ -365,120 +374,25 @@
mark_str
};
ret = runCmd(ARRAY_SIZE(route6_cmd), route6_cmd);
+ // The command might fail during delete if the iface is gone
+ if (add && ret) return ret;
- const char *fwmark6_cmd[] = {
- IP_PATH,
- "-6",
- "rule",
- add ? "add" : "del",
- "prio",
- RULE_PRIO,
- "fwmark",
- mark_str,
- "table",
- mark_str
- };
- ret = runCmd(ARRAY_SIZE(fwmark6_cmd), fwmark6_cmd);
+ /* Best effort, because some kernels might not have the needed TCPMSS */
+ execIptables(V4V6,
+ "-t",
+ "mangle",
+ add ? "-A" : "-D",
+ LOCAL_MANGLE_POSTROUTING,
+ "-p", "tcp", "-o", iface, "--tcp-flags", "SYN,RST", "SYN",
+ "-j",
+ "TCPMSS",
+ "--clamp-mss-to-pmtu",
+ NULL);
-
- if (ret) return ret;
-
- //create the route rule chain
- char chain_str[IFNAMSIZ + 18];
- snprintf(chain_str, sizeof(chain_str), LOCAL_MANGLE_IFACE_FORMAT, iface);
- //code split due to ordering requirements
- if (add) {
- ret = execIptables(V4V6,
- "-t",
- "mangle",
- "-N",
- chain_str,
- NULL);
- //set up the rule for sending premarked packets to the VPN chain
- //Insert these at the top of the chain so they trigger before any UID rules
- ret |= execIptables(V4V6,
- "-t",
- "mangle",
- "-I",
- LOCAL_MANGLE_OUTPUT,
- "3",
- "-m",
- "mark",
- "--mark",
- mark_str,
- "-g",
- chain_str,
- NULL);
- //add a rule to clear the mark in the VPN chain
- //packets marked with SO_MARK already have the iface's mark set but unless they match a
- //route they should hit the network instead of the VPN
- ret |= execIptables(V4V6,
- "-t",
- "mangle",
- "-A",
- chain_str,
- "-j",
- "MARK",
- "--set-mark",
- "0",
- NULL);
-
- /* Best effort, because some kernels might not have the needed TCPMSS */
- execIptables(V4V6,
- "-t",
- "mangle",
- "-A",
- LOCAL_MANGLE_POSTROUTING,
- "-p", "tcp", "-o", iface, "--tcp-flags", "SYN,RST", "SYN",
- "-j",
- "TCPMSS",
- "--clamp-mss-to-pmtu",
- NULL);
-
- } else {
- ret = execIptables(V4V6,
- "-t",
- "mangle",
- "-D",
- LOCAL_MANGLE_OUTPUT,
- "-m",
- "mark",
- "--mark",
- mark_str,
- "-g",
- chain_str,
- NULL);
-
- //clear and delete the chain
- ret |= execIptables(V4V6,
- "-t",
- "mangle",
- "-F",
- chain_str,
- NULL);
-
- ret |= execIptables(V4V6,
- "-t",
- "mangle",
- "-X",
- chain_str,
- NULL);
-
- /* Best effort, because some kernels might not have the needed TCPMSS */
- execIptables(V4V6,
- "-t",
- "mangle",
- "-D",
- LOCAL_MANGLE_POSTROUTING,
- "-p", "tcp", "-o", iface, "--tcp-flags", "SYN,RST", "SYN",
- "-j",
- "TCPMSS",
- "--clamp-mss-to-pmtu",
- NULL);
- }
-
- //set up the needed source IP rewriting
- //NOTE: Without ipv6 NAT in the kernel <3.7 only support V4 NAT
+ // Because the mark gets set after the intial routing decision the source IP address is that
+ // of the original out interface. The only way to change the source IP address to that of the
+ // VPN iface is using source NAT.
+ // TODO: Remove this when we get the mark set correctly before the first routing pass.
ret = execIptables(V4,
"-t",
"nat",
@@ -496,7 +410,7 @@
if (ret) return ret;
- //try and set up for ipv6. ipv6 nat came in the kernel only in 3.7, so this can fail
+ // Try and set up NAT for IPv6 as well. This was only added in Linux 3.7 so this may fail.
ret = execIptables(V6,
"-t",
"nat",
@@ -512,21 +426,28 @@
"MASQUERADE",
NULL);
if (ret) {
- //Without V6 NAT we can't do V6 over VPNs.
- ret = execIptables(V6,
- "-t",
- "filter",
- add ? "-A" : "-D",
- LOCAL_FILTER_OUTPUT,
- "-m",
- "mark",
- "--mark",
- mark_str,
- "-j",
- "REJECT",
- NULL);
+ // Without V6 NAT we can't do V6 over VPNs. If an IPv6 packet matches a VPN rule, then it
+ // will go out on the VPN interface, but without NAT, it will have the wrong source
+ // address. So reject all these packets.
+ // Due to rule application by the time the connection hits the output filter chain the
+ // routing pass based on the new mark has not yet happened. Reject in ip instead.
+ // TODO: Make the VPN code refuse to install IPv6 routes until we don't need IPv6 NAT.
+ const char *reject_cmd[] = {
+ IP_PATH,
+ "-6",
+ "route",
+ add ? "replace" : "del",
+ "unreachable",
+ "default",
+ "table",
+ mark_str
+ };
+ ret = runCmd(ARRAY_SIZE(reject_cmd), reject_cmd);
+ // The command might fail during delete if the iface is gone
+ if (add && ret) return ret;
+
}
- return ret;
+ return 0;
}
@@ -547,24 +468,25 @@
}
int mark = tableIndex + BASE_TABLE_NUMBER;
char mark_str[11] = {0};
- char chain_str[IFNAMSIZ + 18];
char dest_str[44]; // enough to store an IPv6 address + 3 character bitmask
snprintf(mark_str, sizeof(mark_str), "%d", mark);
- snprintf(chain_str, sizeof(chain_str), LOCAL_MANGLE_IFACE_FORMAT, iface);
snprintf(dest_str, sizeof(dest_str), "%s/%d", dest, prefix);
- return execIptables(getIptablesTarget(dest),
- "-t",
- "mangle",
- add ? "-A" : "-D",
- chain_str,
- "-d",
- dest_str,
- "-j",
- "MARK",
- "--set-mark",
- mark_str,
- NULL);
+ const char *rule_cmd[] = {
+ IP_PATH,
+ getVersion(dest_str),
+ "rule",
+ add ? "add" : "del",
+ "prio",
+ RULE_PRIO,
+ "to",
+ dest_str,
+ "fwmark",
+ mark_str,
+ "table",
+ mark_str
+ };
+ return runCmd(ARRAY_SIZE(rule_cmd), rule_cmd);
}
int SecondaryTableController::addUidRule(const char *iface, int uid_start, int uid_end) {
@@ -594,9 +516,9 @@
}
}
char uid_str[24] = {0};
- char chain_str[IFNAMSIZ + 18];
snprintf(uid_str, sizeof(uid_str), "%d-%d", uid_start, uid_end);
- snprintf(chain_str, sizeof(chain_str), LOCAL_MANGLE_IFACE_FORMAT, iface);
+ char mark_str[11] = {0};
+ snprintf(mark_str, sizeof(mark_str), "%d", mark);
return execIptables(V4V6,
"-t",
"mangle",
@@ -606,8 +528,10 @@
"owner",
"--uid-owner",
uid_str,
- "-g",
- chain_str,
+ "-j",
+ "MARK",
+ "--set-mark",
+ mark_str,
NULL);
}
@@ -620,21 +544,6 @@
}
int SecondaryTableController::setHostExemption(const char *host, bool add) {
- IptablesTarget target = !strcmp(getVersion(host), "-4") ? V4 : V6;
- char protect_mark_str[11];
- snprintf(protect_mark_str, sizeof(protect_mark_str), "%d", PROTECT_MARK);
- int ret = execIptables(target,
- "-t",
- "mangle",
- add ? "-A" : "-D",
- LOCAL_MANGLE_EXEMPT,
- "-d",
- host,
- "-j",
- "MARK",
- "--set-mark",
- protect_mark_str,
- NULL);
const char *cmd[] = {
IP_PATH,
getVersion(host),
@@ -647,8 +556,7 @@
"table",
"main"
};
- ret |= runCmd(ARRAY_SIZE(cmd), cmd);
- return ret;
+ return runCmd(ARRAY_SIZE(cmd), cmd);
}
void SecondaryTableController::getUidMark(SocketClient *cli, int uid) {
diff --git a/SecondaryTableController.h b/SecondaryTableController.h
index 716e11d..e286075 100644
--- a/SecondaryTableController.h
+++ b/SecondaryTableController.h
@@ -59,10 +59,7 @@
static const char* LOCAL_MANGLE_OUTPUT;
static const char* LOCAL_MANGLE_POSTROUTING;
- static const char* LOCAL_MANGLE_EXEMPT;
- static const char* LOCAL_MANGLE_IFACE_FORMAT;
static const char* LOCAL_NAT_POSTROUTING;
- static const char* LOCAL_FILTER_OUTPUT;
private:
