lib: Add per-user packet pools

The IRMd will now check the user UID and GID for privileged access,
avoiding unprivileged users being able to disrupt all IPC (e.g. by
shm_open the single pool and corrupting its metadata).

Non-privileged users are now limited to a PUP (per-user pool) for
sending/receiving packets. It is still created by the IRMd, but owned
by the user (uid) with 600 permissions. It does not add additional
copies for local IPC between their own processes (i.e. over the local
IPCP), but packets between processes owned by a different user or
destined over the network (other IPCPs) will incur a copy when
crossing the PUP / PUP or the PUP / GSPP boundary.

Privileged users and users in the ouroboros group still have direct
access to the GSPP (globally shared private pool) for packet transfer
that will avoid additional copies when processing packets between
processes owned by different users and to the network.

This aligns the security model with UNIX trust domains defined by UID
and GID by leveraging file permission on the pools in shared memory.

┌─────────────────────────────────────────────────────────────┐
│ Source Pool    │ Dest Pool      │ Operation    │ Copies     │
├─────────────────────────────────────────────────────────────┤
│ GSPP           │ GSPP           │ Zero-copy    │ 0          │
│ PUP.uid        │ PUP.uid        │ Zero-copy    │ 0          │
│ PUP.uid1       │ PUP.uid2       │ memcpy()     │ 1          │
│ PUP.uid        │ GSPP           │ memcpy()     │ 1          │
│ GSPP           │ PUP.uid        │ memcpy()     │ 1          │
└─────────────────────────────────────────────────────────────┘

This also renames the struct ai ("application instance") in dev.c to
struct proc (process).

Signed-off-by: Dimitri Staessens <dimitri@ouroboros.rocks>
Signed-off-by: Sander Vrijders <sander@ouroboros.rocks>

2 files changed, 22 insertions, 28 deletions

diff --git a/src/irmd/reg/tests/proc_test.c b/src/irmd/reg/tests/proc_test.c
index d53f18ec..c4e689f0 100644
--- a/src/irmd/reg/tests/proc_test.c
+++ b/src/irmd/reg/tests/proc_test.c
@@ -27,13 +27,17 @@
 #define TEST_PID  65534
 #define TEST_PROG "usr/bin/testprog"
 
+#define TEST_PROC {           \
+        .pid = TEST_PID,      \
+        .prog = TEST_PROG,    \
+        .uid = getuid(),      \
+        .gid = getgid()       \
+}
+
 static int test_reg_proc_create_destroy(void)
 {
         struct reg_proc * proc;
-        struct proc_info  info = {
-                .pid =  TEST_PID,
-                .prog = TEST_PROG
-        };
+        struct proc_info  info = TEST_PROC;
 
         TEST_START();
 
@@ -56,10 +60,7 @@ static int test_reg_proc_create_destroy(void)
 static int test_reg_proc_add_name(void)
 {
         struct reg_proc * proc;
-        struct proc_info  info = {
-                .pid  = TEST_PID,
-                .prog = TEST_PROG
-        };
+        struct proc_info  info = TEST_PROC;
 
         char * name = "testname";
 
diff --git a/src/irmd/reg/tests/reg_test.c b/src/irmd/reg/tests/reg_test.c
index 07d0a198..f7a4de8e 100644
--- a/src/irmd/reg/tests/reg_test.c
+++ b/src/irmd/reg/tests/reg_test.c
@@ -21,6 +21,8 @@
  */
 
 
+#include "../pool.c"
+#undef OUROBOROS_PREFIX
 #include "../reg.c"
 
 #include <test/test.h>
@@ -35,6 +37,12 @@
 #define TEST_DATA     "testpbufdata"
 #define TEST_DATA2    "testpbufdata2"
 #define TEST_LAYER    "testlayer"
+#define TEST_PROC_INFO {      \
+        .pid = TEST_PID,      \
+        .prog = TEST_PROG,    \
+        .uid = 0,             \
+        .gid = 0              \
+}
 #define REG_TEST_FAIL() \
         do { TEST_FAIL(); reg_clear(); return TEST_RC_FAIL;} while(0)
 
@@ -852,10 +860,7 @@ static int test_reg_name(void)
 
 static int test_reg_create_proc(void)
 {
-        struct proc_info info = {
-                .pid =  TEST_PID,
-                .prog = TEST_PROG
-        };
+        struct proc_info info = TEST_PROC_INFO;
 
         TEST_START();
 
@@ -1011,10 +1016,7 @@ static int test_reg_prog(void)
 
 static int test_bind_proc(void)
 {
-        struct proc_info pinfo = {
-                .pid =  TEST_PID,
-                .prog = TEST_PROG
-        };
+        struct proc_info pinfo = TEST_PROC_INFO;
 
         struct name_info ninfo = {
                 .name   = TEST_NAME,
@@ -1167,10 +1169,7 @@ static int test_inherit_prog(void)
                 .name = TEST_PROG
         };
 
-        struct proc_info procinfo = {
-                .pid  = TEST_PID,
-                .prog = TEST_PROG
-        };
+        struct proc_info procinfo = TEST_PROC_INFO;
 
         char * exec[] = { TEST_PROG, NULL};
 
@@ -1308,10 +1307,7 @@ static void * test_call_flow_accept(void * o)
         struct timespec timeo = TIMESPEC_INIT_MS(10);
         buffer_t        pbuf = BUF_INIT;
 
-        struct proc_info pinfo = {
-                .pid =  TEST_PID,
-                .prog = TEST_PROG
-        };
+        struct proc_info pinfo = TEST_PROC_INFO;
 
         struct flow_info info = {
                 .n_pid = pinfo.pid,
@@ -1663,10 +1659,7 @@ static int test_wait_proc_success(void)
         struct timespec  abstime;
         struct timespec  timeo = TIMESPEC_INIT_S(10);
         pthread_t        thr;
-        struct proc_info info = {
-                .pid  = TEST_PID,
-                .prog = TEST_PROG
-        };
+        struct proc_info info = TEST_PROC_INFO;
 
         TEST_START();