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IPC privileges fixes

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Kernel:
o Remove s_ipc_sendrec, instead using s_ipc_to for all send primitives
o Centralize s_ipc_to bit manipulation,
  - disallowing assignment of bits pointing to unused priv structs;
  - preventing send-to-self by not setting bit for own priv struct;
  - preserving send mask matrix symmetry in all cases
o Add IPC send mask checks to SENDA, which were missing entirely somehow
o Slightly improve IPC stats accounting for SENDA
o Remove SYSTEM from user processes' send mask
o Half-fix the dependency between boot image order and process numbers,
  - correcting the table order of the boot processes;
  - documenting the order requirement needed for proper send masks;
  - warning at boot time if the order is violated

RS:
o Add support in /etc/drivers.conf for servers that talk to user processes,
  - disallowing IPC to user processes if no "ipc" field is present
  - adding a special "USER" label to explicitly allow IPC to user processes
o Always apply IPC masks when specified; remove -i flag from service(8)
o Use kernel send mask symmetry to delay adding IPC permissions for labels
  that do not exist yet, adding them to that label's process upon creation
o Add VM to ipc permissions list for rtl8139 and fxp in drivers.conf

Left to future fixes:
o Removal of the table order vs process numbers dependency altogether,
  possibly using per-process send list structures as used for SYSTEM calls
o Proper assignment of send masks to boot processes;
  some of the assigned (~0) masks are much wider than necessary
o Proper assignment of IPC send masks for many more servers in drivers.conf
o Removal of the debugging warning about the now legitimate case where RS's
  add_forward_ipc cannot find the IPC destination's label yet
This commit is contained in:
David van Moolenbroek
2009-07-02 16:25:31 +00:00
parent aa84986819
commit b8b8f537bd
13 changed files with 297 additions and 170 deletions
Download Patch File Download Diff File Expand all files Collapse all files

5
servers/is/dmp_kernel.c
View File

@@ -363,7 +363,7 @@ PUBLIC void privileges_dmp()
return;
}
printf("\n--nr-id-name---- -flags- -traps- grants -ipc_to-- -ipc_sr-- -system calls--\n");
printf("\n--nr-id-name---- -flags- -traps- grants -ipc_to-- -system calls--\n");
PROCLOOP(rp, oldrp)
r = -1;
@@ -379,9 +379,6 @@ PUBLIC void privileges_dmp()
for (i=0; i < NR_SYS_PROCS; i += BITCHUNK_BITS) {
printf(" %04x", get_sys_bits(sp->s_ipc_to, i));
}
for (i=0; i < NR_SYS_PROCS; i += BITCHUNK_BITS) {
printf(" %04x", get_sys_bits(sp->s_ipc_sendrec, i));
}
printf(" ");
for (i=0; i < NR_SYS_CALLS; i += BITCHUNK_BITS) {

272
servers/rs/manager.c
View File

@@ -30,6 +30,12 @@ FORWARD _PROTOTYPE( int stop_service, (struct rproc *rp,int how) );
FORWARD _PROTOTYPE( int fork_nb, (void) );
FORWARD _PROTOTYPE( int read_exec, (struct rproc *rp) );
FORWARD _PROTOTYPE( void run_script, (struct rproc *rp) );
FORWARD _PROTOTYPE( char *get_next_label, (char *ptr, char *label,
char *caller_label) );
FORWARD _PROTOTYPE( void add_forward_ipc, (struct rproc *rp,
struct priv *privp) );
FORWARD _PROTOTYPE( void add_backward_ipc, (struct rproc *rp,
struct priv *privp) );
FORWARD _PROTOTYPE( void init_privs, (struct rproc *rp, struct priv *privp) );
FORWARD _PROTOTYPE( void init_pci, (struct rproc *rp, int endpoint) );
@@ -1043,6 +1049,176 @@ struct rproc *rp;
}
/*===========================================================================*
* get_next_label *
*===========================================================================*/
PRIVATE char *get_next_label(ptr, label, caller_label)
char *ptr;
char *label;
char *caller_label;
{
/* Get the next label from the list of (IPC) labels.
*/
char *p, *q;
size_t len;
for (p= ptr; p[0] != '\0'; p= q)
{
/* Skip leading space */
while (p[0] != '\0' && isspace((unsigned char)p[0]))
p++;
/* Find start of next word */
q= p;
while (q[0] != '\0' && !isspace((unsigned char)q[0]))
q++;
if (q == p)
continue;
len= q-p;
if (len > MAX_LABEL_LEN)
{
printf(
"rs:get_next_label: bad ipc list entry '.*s' for %s: too long\n",
len, p, caller_label);
continue;
}
memcpy(label, p, len);
label[len]= '\0';
return q; /* found another */
}
return NULL; /* done */
}
/*===========================================================================*
* add_forward_ipc *
*===========================================================================*/
PRIVATE void add_forward_ipc(rp, privp)
struct rproc *rp;
struct priv *privp;
{
/* Add IPC send permissions to a process based on that process's IPC
* list.
*/
char label[MAX_LABEL_LEN+1], *p;
struct rproc *tmp_rp;
endpoint_t proc_nr_e;
int slot_nr, priv_id;
p = rp->r_ipc_list;
while ((p = get_next_label(p, label, rp->r_label)) != NULL) {
if (strcmp(label, "SYSTEM") == 0)
proc_nr_e= SYSTEM;
else if (strcmp(label, "USER") == 0)
proc_nr_e= INIT_PROC_NR; /* all user procs */
else if (strcmp(label, "PM") == 0)
proc_nr_e= PM_PROC_NR;
else if (strcmp(label, "VFS") == 0)
proc_nr_e= FS_PROC_NR;
else if (strcmp(label, "RS") == 0)
proc_nr_e= RS_PROC_NR;
else if (strcmp(label, "LOG") == 0)
proc_nr_e= LOG_PROC_NR;
else if (strcmp(label, "TTY") == 0)
proc_nr_e= TTY_PROC_NR;
else if (strcmp(label, "DS") == 0)
proc_nr_e= DS_PROC_NR;
else if (strcmp(label, "VM") == 0)
proc_nr_e= VM_PROC_NR;
else
{
/* Try to find process */
for (slot_nr = 0; slot_nr < NR_SYS_PROCS;
slot_nr++)
{
tmp_rp = &rproc[slot_nr];
if (!(tmp_rp->r_flags & RS_IN_USE))
continue;
if (strcmp(tmp_rp->r_label, label) == 0)
break;
}
if (slot_nr >= NR_SYS_PROCS)
{
printf(
"add_forward_ipc: unable to find '%s'\n",
label);
continue;
}
proc_nr_e= tmp_rp->r_proc_nr_e;
}
priv_id= sys_getprivid(proc_nr_e);
if (priv_id < 0)
{
printf(
"add_forward_ipc: unable to get priv_id for '%s': %d\n",
label, priv_id);
continue;
}
set_sys_bit(privp->s_ipc_to, priv_id);
}
}
/*===========================================================================*
* add_backward_ipc *
*===========================================================================*/
PRIVATE void add_backward_ipc(rp, privp)
struct rproc *rp;
struct priv *privp;
{
/* Add IPC send permissions to a process based on other processes' IPC
* lists. This is enough to allow each such two processes to talk to
* each other, as the kernel guarantees send mask symmetry. We need to
* add these permissions now because the current process may not yet
* have existed at the time that the other process was initialized.
*/
char label[MAX_LABEL_LEN+1], *p;
struct rproc *rrp;
int priv_id, found;
for (rrp=BEG_RPROC_ADDR; rrp<END_RPROC_ADDR; rrp++) {
if (!(rrp->r_flags & RS_IN_USE))
continue;
/* If an IPC target list was provided for the process being
* checked here, make sure that the label of the new process
* is in that process's list.
*/
if (rrp->r_ipc_list[0]) {
found = 0;
p = rrp->r_ipc_list;
while ((p = get_next_label(p, label, rp->r_label)) !=
NULL) {
if (!strcmp(rp->r_label, label)) {
found = 1;
break;
}
}
if (!found)
continue;
}
priv_id= sys_getprivid(rrp->r_proc_nr_e);
if (priv_id < 0)
{
printf(
"add_backward_ipc: unable to get priv_id for '%s': %d\n",
label, priv_id);
continue;
}
set_sys_bit(privp->s_ipc_to, priv_id);
}
}
/*===========================================================================*
* init_privs *
*===========================================================================*/
@@ -1051,13 +1227,8 @@ struct rproc *rp;
struct priv *privp;
{
int i, src_bits_per_word, dst_bits_per_word, src_word, dst_word,
src_bit, call_nr, chunk, bit, priv_id, slot_nr;
endpoint_t proc_nr_e;
size_t len;
src_bit, call_nr;
unsigned long mask;
char *p, *q;
struct rproc *tmp_rp;
char label[MAX_LABEL_LEN+1];
/* Clear s_k_call_mask */
memset(privp->s_k_call_mask, '\0', sizeof(privp->s_k_call_mask));
@@ -1088,98 +1259,21 @@ struct priv *privp;
}
}
/* Clear s_ipc_to and s_ipc_sendrec */
/* Clear s_ipc_to */
memset(&privp->s_ipc_to, '\0', sizeof(privp->s_ipc_to));
memset(&privp->s_ipc_sendrec, '\0', sizeof(privp->s_ipc_sendrec));
if (strlen(rp->r_ipc_list) != 0)
{
for (p= rp->r_ipc_list; p[0] != '\0'; p= q)
{
/* Skip leading space */
while (p[0] != '\0' && isspace((unsigned char)p[0]))
p++;
add_forward_ipc(rp, privp);
add_backward_ipc(rp, privp);
/* Find start of next word */
q= p;
while (q[0] != '\0' && !isspace((unsigned char)q[0]))
q++;
if (q == p)
continue;
len= q-p;
if (len+1 > sizeof(label))
{
printf(
"rs:init_privs: bad ipc list entry '.*s' for %s: too long\n",
len, p, rp->r_label);
continue;
}
memcpy(label, p, len);
label[len]= '\0';
if (strcmp(label, "SYSTEM") == 0)
proc_nr_e= SYSTEM;
else if (strcmp(label, "PM") == 0)
proc_nr_e= PM_PROC_NR;
else if (strcmp(label, "VFS") == 0)
proc_nr_e= FS_PROC_NR;
else if (strcmp(label, "RS") == 0)
proc_nr_e= RS_PROC_NR;
else if (strcmp(label, "LOG") == 0)
proc_nr_e= LOG_PROC_NR;
else if (strcmp(label, "TTY") == 0)
proc_nr_e= TTY_PROC_NR;
else if (strcmp(label, "DS") == 0)
proc_nr_e= DS_PROC_NR;
else
{
/* Try to find process */
for (slot_nr = 0; slot_nr < NR_SYS_PROCS;
slot_nr++)
{
tmp_rp = &rproc[slot_nr];
if (!(tmp_rp->r_flags & RS_IN_USE))
continue;
if (strcmp(tmp_rp->r_label, label) == 0)
break;
}
if (slot_nr >= NR_SYS_PROCS)
{
printf(
"init_privs: unable to find '%s'\n",
label);
continue;
}
proc_nr_e= tmp_rp->r_proc_nr_e;
}
priv_id= sys_getprivid(proc_nr_e);
if (priv_id < 0)
{
printf(
"init_privs: unable to get priv_id for '%s': %d\n",
label, priv_id);
continue;
}
chunk= (priv_id / (sizeof(bitchunk_t)*8));
bit= (priv_id % (sizeof(bitchunk_t)*8));
privp->s_ipc_to.chunk[chunk] |= (1 << bit);
privp->s_ipc_sendrec.chunk[chunk] |= (1 << bit);
}
}
else
{
for (i= 0; i<sizeof(privp->s_ipc_to)*8; i++)
for (i= 0; i<NR_SYS_PROCS; i++)
{
chunk= (i / (sizeof(bitchunk_t)*8));
bit= (i % (sizeof(bitchunk_t)*8));
privp->s_ipc_to.chunk[chunk] |= (1 << bit);
}
for (i= 0; i<sizeof(privp->s_ipc_sendrec)*8; i++)
{
chunk= (i / (sizeof(bitchunk_t)*8));
bit= (i % (sizeof(bitchunk_t)*8));
privp->s_ipc_sendrec.chunk[chunk] |= (1 << bit);
if (i != USER_PRIV_ID)
set_sys_bit(privp->s_ipc_to, i);
}
}
}

9
servers/rs/service.c
View File

@@ -134,7 +134,6 @@ PRIVATE int parse_arguments(int argc, char **argv)
int req_nr;
int c, i;
int c_flag;
int i_flag=0;
c_flag= 0;
while (c= getopt(argc, argv, "ci?"), c != -1)
@@ -148,7 +147,9 @@ PRIVATE int parse_arguments(int argc, char **argv)
c_flag= 1;
break;
case 'i':
i_flag= 1;
/* Legacy - remove later */
fputs("WARNING: obsolete -i flag passed to service(8)\n",
stderr);
break;
default:
fprintf(stderr, "%s: getopt failed: %c\n",
@@ -186,11 +187,9 @@ PRIVATE int parse_arguments(int argc, char **argv)
req_nr= RS_START;
rs_start.rss_flags= 0;
rs_start.rss_flags= RF_IPC_VALID;
if (c_flag)
rs_start.rss_flags |= RF_COPY;
if (i_flag)
rs_start.rss_flags |= RF_IPC_VALID;
if (do_run)
{