Add support for tracing emulations. At the moment, all emulations are
compiled in. It might make sense to #ifdef them in the future, though this impeeds readability.
This commit is contained in:
Todd C. Miller
173
mon_systrace.c
173
mon_systrace.c
@@ -44,6 +44,7 @@
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#endif /* HAVE_ERR_H */
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#include "sudo.h"
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#include "trace_systrace.h"
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#ifndef lint
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static const char rcsid[] = "$Sudo$";
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@@ -55,28 +56,20 @@ struct listhead {
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struct childinfo {
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pid_t pid;
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struct passwd *pw;
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struct syscallaction *action;
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struct childinfo *next;
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};
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struct syscallhandler {
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int num;
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void (*handler) __P((int, struct str_msg_ask *, struct systrace_answer *));
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struct syscallhandler *next;
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};
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void check_exec __P((int, struct str_msg_ask *,
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struct systrace_answer *));
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void check_syscall __P((int, struct str_msg_ask *,
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struct systrace_answer *, struct listhead *));
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struct systrace_answer *));
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int decode_args __P((int, pid_t, struct str_msg_ask *));
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int set_policy __P((int, pid_t, struct listhead *));
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int set_policy __P((int, struct childinfo *));
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int systrace_open __P((void));
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int systrace_read __P((int, pid_t, void *, void *, size_t));
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int systrace_run __P((char *, char **, int));
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int switch_emulation __P((int, struct str_message *));
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ssize_t read_string __P((int, pid_t, void *, char *, size_t));
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void new_child __P((pid_t, pid_t));
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void new_handler __P((struct listhead *, int,
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void (*)(int, struct str_msg_ask *,
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struct systrace_answer *)));
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void rm_child __P((pid_t));
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void update_child __P((pid_t, uid_t));
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struct childinfo *find_child __P((pid_t));
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@@ -140,7 +133,6 @@ systrace_attach(pid)
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{
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struct systrace_answer ans;
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struct str_message msg;
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struct listhead handlers;
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sigaction_t sa, osa;
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sigset_t set, oset;
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ssize_t nread;
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@@ -207,10 +199,10 @@ systrace_attach(pid)
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goto fail;
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}
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if (set_policy(fd, pid, &handlers) != 0)
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new_child(-1, pid);
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if (set_policy(fd, children.first) != 0)
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goto fail;
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new_child(-1, pid);
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if (kill(pid, SIGUSR1) != 0) {
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warn("unable to wake up sleeping child");
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_exit(1);
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@@ -256,25 +248,27 @@ systrace_attach(pid)
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memset(&ans, 0, sizeof(ans));
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ans.stra_pid = msg.msg_pid;
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ans.stra_seqnr = msg.msg_seqnr;
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check_syscall(fd, &msg.msg_data.msg_ask, &ans, &handlers);
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check_syscall(fd, &msg.msg_data.msg_ask, &ans);
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if ((ioctl(fd, STRIOCANSWER, &ans)) == -1)
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goto fail;
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break;
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case SYSTR_MSG_EMUL:
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/*
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* XXX - need to redo policy if we change emulation.
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* that means we need to know in advance what
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* the various emulations are.
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*/
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warnx("change in emul");
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/* Change in emulation. */
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memset(&ans, 0, sizeof(ans));
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ans.stra_pid = msg.msg_pid;
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ans.stra_seqnr = msg.msg_seqnr;
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ans.stra_policy = SYSTR_POLICY_PERMIT;
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if (switch_emulation(fd, &msg) == 0)
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ans.stra_policy = SYSTR_POLICY_PERMIT;
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else {
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warnx("unsupported emulation \"%s\"",
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msg.msg_data.msg_emul.emul);
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ans.stra_policy = SYSTR_POLICY_NEVER;
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}
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if ((ioctl(fd, STRIOCANSWER, &ans)) == -1)
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goto fail;
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break;
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case SYSTR_MSG_POLICYFREE:
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break;
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@@ -298,27 +292,9 @@ fail:
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_exit(1);
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}
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/*
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* Push a new handler to the head of the list.
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*/
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void
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new_handler(head, num, handler)
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struct listhead *head;
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int num;
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void (*handler) __P((int, struct str_msg_ask *, struct systrace_answer *));
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{
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struct syscallhandler *entry;
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entry = (struct syscallhandler *) emalloc(sizeof(*entry));
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entry->num = num;
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entry->handler = handler;
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entry->next = head->first;
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head->first = entry;
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}
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/*
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* Push a new child to the head of the list, inheriting the struct pw
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* of its parent. XXX - do ref counting on pw instead of copying.
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* of its parent.
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*/
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void
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new_child(ppid, pid)
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@@ -327,18 +303,48 @@ new_child(ppid, pid)
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{
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struct childinfo *entry;
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struct passwd *pw;
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struct syscallaction *action;
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struct emulation *emul;
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if (ppid != -1 && (entry = find_child(ppid)) != NULL)
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if (ppid != -1 && (entry = find_child(ppid)) != NULL) {
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pw = entry->pw;
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else
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action = entry->action;
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} else {
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pw = runas_pw;
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for (emul = emulations; emul != NULL; emul++)
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if (strcmp(emul->name, "native") == 0) {
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action = emul->action;
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break;
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}
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if (emul == NULL)
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errx(1, "unable to find native emulation!");
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}
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entry = (struct childinfo *) emalloc(sizeof(*entry));
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entry->pid = pid;
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entry->pw = sudo_pwdup(pw, 0);
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entry->action = action;
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entry->next = children.first;
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children.first = entry;
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}
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int
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switch_emulation(fd, msgp)
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int fd;
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struct str_message *msgp;
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{
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struct childinfo *entry;
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struct emulation *emul;
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if ((entry = find_child(msgp->msg_pid)) == NULL)
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return(-1);
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for (emul = emulations; emul != NULL; emul++)
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if (strcmp(emul->name, msgp->msg_data.msg_emul.emul) == 0) {
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entry->action = emul->action;
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return(set_policy(fd, entry));
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}
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return(-1);
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}
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/*
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* Remove the named pid from the list.
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*/
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@@ -409,13 +415,13 @@ update_child(pid, uid)
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* Create a policy that intercepts execve and lets all others go free.
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*/
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int
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set_policy(fd, pid, handlers)
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set_policy(fd, child)
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int fd;
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pid_t pid;
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struct listhead *handlers;
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struct childinfo *child;
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{
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int i;
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struct syscallaction *sca;
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struct systrace_policy pol;
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int i;
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pol.strp_op = SYSTR_POLICY_NEW;
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pol.strp_num = -1;
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@@ -423,55 +429,20 @@ set_policy(fd, pid, handlers)
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if (ioctl(fd, STRIOCPOLICY, &pol) == -1)
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return(-1);
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handlers->first = NULL;
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for (i = 0; i < SYS_MAXSYSCALL; i++) {
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pol.strp_op = SYSTR_POLICY_ASSIGN;
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pol.strp_pid = pid;
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pol.strp_pid = child->pid;
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if (ioctl(fd, STRIOCPOLICY, &pol) == -1)
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return(-1);
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pol.strp_op = SYSTR_POLICY_MODIFY;
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switch (pol.strp_code = i) {
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#ifdef SYS_exec
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case SYS_exec:
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pol.strp_policy = SYSTR_POLICY_ASK;
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new_handler(handlers, i, check_exec);
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break;
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#endif
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#ifdef SYS_execv
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case SYS_execv:
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pol.strp_policy = SYSTR_POLICY_ASK;
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new_handler(handlers, i, check_exec);
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break;
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#endif
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#ifdef SYS_execve
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case SYS_execve:
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pol.strp_policy = SYSTR_POLICY_ASK;
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new_handler(handlers, i, check_exec);
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break;
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#endif
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#ifdef SYS_fexecve
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case SYS_fexecve:
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pol.strp_policy = SYSTR_POLICY_NEVER; /* not checkable */
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break;
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#endif
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#ifdef SYS_setuid
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case SYS_setuid:
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#endif
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#ifdef SYS_seteuid
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case SYS_seteuid:
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#endif
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#ifdef SYS_setreuid
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case SYS_setreuid:
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#endif
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#ifdef SYS_setresuid
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case SYS_setresuid:
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#endif
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pol.strp_policy = SYSTR_POLICY_ASK;
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break;
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default:
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pol.strp_policy = SYSTR_POLICY_PERMIT;
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pol.strp_policy = SYSTR_POLICY_PERMIT;
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pol.strp_code = i;
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for (sca = child->action; sca->code != -1; sca++) {
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if (sca->code == i) {
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pol.strp_policy = sca->policy;
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break;
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}
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}
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if (ioctl(fd, STRIOCPOLICY, &pol) == -1)
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return(-1);
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@@ -540,21 +511,27 @@ read_string(fd, pid, addr, buf, bufsiz)
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}
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void
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check_syscall(fd, askp, ansp, handlers)
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check_syscall(fd, askp, ansp)
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int fd;
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struct str_msg_ask *askp;
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struct systrace_answer *ansp;
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struct listhead *handlers;
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{
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struct syscallhandler *h;
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struct syscallaction *sca;
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struct childinfo *child;
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for (h = handlers->first; h != NULL; h = h->next) {
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if (h->num == askp->code) {
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h->handler(fd, askp, ansp);
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return;
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if ((child = find_child(ansp->stra_pid)) == NULL) {
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warnx("unable to find child with pid %d", ansp->stra_pid);
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ansp->stra_policy = SYSTR_POLICY_NEVER;
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return;
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}
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ansp->stra_policy = SYSTR_POLICY_PERMIT; /* accept by default */
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for (sca = child->action; sca->code != -1; sca++) {
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if (sca->code == askp->code) {
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if (sca->handler != NULL)
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sca->handler(fd, askp, ansp);
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break;
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}
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}
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ansp->stra_policy = SYSTR_POLICY_PERMIT; /* accept unhandled syscalls */
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}
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/*
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178
mon_systrace.h
Normal file
178
mon_systrace.h
Normal file
@@ -0,0 +1,178 @@
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/*
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* Copyright (c) 2004 Todd C. Miller <Todd.Miller@courtesan.com>
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*
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* Permission to use, copy, modify, and distribute this software for any
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* purpose with or without fee is hereby granted, provided that the above
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* copyright notice and this permission notice appear in all copies.
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*
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* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
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* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
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* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
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* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
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* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
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* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
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* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
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*/
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void check_exec __P((int, struct str_msg_ask *,
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struct systrace_answer *));
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struct syscallaction {
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int code;
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int policy;
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void (*handler) __P((int, struct str_msg_ask *, struct systrace_answer *));
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};
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struct syscallaction syscalls_openbsd[] = {
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{ 23, SYSTR_POLICY_ASK, NULL}, /* OPENBSD_SYS_setuid */
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{ 59, SYSTR_POLICY_ASK, check_exec}, /* OPENBSD_SYS_execve */
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{ 126, SYSTR_POLICY_ASK, NULL}, /* OPENBSD_SYS_setreuid */
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{ 183, SYSTR_POLICY_ASK, NULL}, /* OPENBSD_SYS_seteuid */
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{ 282, SYSTR_POLICY_ASK, NULL}, /* OPENBSD_SYS_setresuid */
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{ -1, -1, NULL}
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};
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struct syscallaction syscalls_bsdos[] = {
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{ 23, SYSTR_POLICY_ASK, NULL}, /* BSDOS_SYS_setuid */
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{ 59, SYSTR_POLICY_ASK, check_exec}, /* BSDOS_SYS_execve */
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{ 126, SYSTR_POLICY_ASK, NULL}, /* BSDOS_SYS_setreuid */
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{ 183, SYSTR_POLICY_ASK, NULL}, /* BSDOS_SYS_seteuid */
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{ -1, -1, NULL}
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};
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struct syscallaction syscalls_freebsd[] = {
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{ 23, SYSTR_POLICY_ASK, NULL}, /* FREEBSD_SYS_setuid */
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{ 59, SYSTR_POLICY_ASK, check_exec}, /* FREEBSD_SYS_execve */
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{ 126, SYSTR_POLICY_ASK, NULL}, /* FREEBSD_SYS_setreuid */
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{ 183, SYSTR_POLICY_ASK, NULL}, /* FREEBSD_SYS_seteuid */
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{ 311, SYSTR_POLICY_ASK, NULL}, /* FREEBSD_SYS_setresuid */
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{ -1, -1, NULL}
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};
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struct syscallaction syscalls_netbsd[] = {
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{ 23, SYSTR_POLICY_ASK, NULL}, /* NETBSD_SYS_setuid */
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{ 59, SYSTR_POLICY_ASK, check_exec}, /* NETBSD_SYS_execve */
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{ 126, SYSTR_POLICY_ASK, NULL}, /* NETBSD_SYS_setreuid */
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{ 183, SYSTR_POLICY_ASK, NULL}, /* NETBSD_SYS_seteuid */
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{ -1, -1, NULL}
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};
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struct syscallaction syscalls_hpux[] = {
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{ 11, SYSTR_POLICY_ASK, NULL}, /* HPUX_SYS_execv */
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{ 23, SYSTR_POLICY_ASK, NULL}, /* HPUX_SYS_setuid */
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{ 59, SYSTR_POLICY_ASK, check_exec}, /* HPUX_SYS_execve */
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{ 126, SYSTR_POLICY_ASK, NULL}, /* HPUX_SYS_setresuid */
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{ -1, -1, NULL}
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};
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struct syscallaction syscalls_ibsc2[] = {
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{ 11, SYSTR_POLICY_ASK, NULL}, /* ISCS2_SYS_execv */
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{ 23, SYSTR_POLICY_ASK, NULL}, /* ISCS2_SYS_setuid */
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{ 59, SYSTR_POLICY_ASK, check_exec}, /* ISCS2_SYS_execve */
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{ -1, -1, NULL}
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};
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struct syscallaction syscalls_linux[] = {
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{ 11, SYSTR_POLICY_ASK, check_exec}, /* LINUX_SYS_execve */
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{ 23, SYSTR_POLICY_ASK, NULL}, /* LINUX_SYS_setuid16 */
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{ 70, SYSTR_POLICY_ASK, NULL}, /* LINUX_SYS_setreuid16 */
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{ 138, SYSTR_POLICY_ASK, NULL}, /* LINUX_SYS_setfsuid16 */
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{ 164, SYSTR_POLICY_ASK, NULL}, /* LINUX_SYS_setresuid16 */
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{ 203, SYSTR_POLICY_ASK, NULL}, /* LINUX_SYS_setreuid */
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{ 208, SYSTR_POLICY_ASK, NULL}, /* LINUX_SYS_setresuid */
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{ 213, SYSTR_POLICY_ASK, NULL}, /* LINUX_SYS_setuid */
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{ 215, SYSTR_POLICY_ASK, NULL}, /* LINUX_SYS_setfsuid */
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{ -1, -1, NULL}
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};
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struct syscallaction syscalls_osf1[] = {
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{ 23, SYSTR_POLICY_ASK, NULL}, /* OSF1_SYS_setuid */
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{ 59, SYSTR_POLICY_ASK, check_exec}, /* OSF1_SYS_execve */
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{ 126, SYSTR_POLICY_ASK, NULL}, /* OSF1_SYS_setreuid */
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{ -1, -1, NULL}
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};
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struct syscallaction syscalls_sunos[] = {
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{ 11, SYSTR_POLICY_ASK, NULL}, /* SUNOS_SYS_execv */
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{ 23, SYSTR_POLICY_ASK, NULL}, /* SUNOS_SYS_setuid */
|
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{ 59, SYSTR_POLICY_ASK, check_exec}, /* SUNOS_SYS_execve */
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{ 126, SYSTR_POLICY_ASK, NULL}, /* SUNOS_SYS_setreuid */
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{ -1, -1, NULL}
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};
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struct syscallaction syscalls_svr4[] = {
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{ 11, SYSTR_POLICY_ASK, NULL}, /* SVR4_SYS_execv */
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{ 23, SYSTR_POLICY_ASK, NULL}, /* SVR4_SYS_setuid */
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{ 59, SYSTR_POLICY_ASK, check_exec}, /* SVR4_SYS_execve */
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{ 141, SYSTR_POLICY_ASK, NULL}, /* SVR4_SYS_seteuid */
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{ 202, SYSTR_POLICY_ASK, NULL}, /* SVR4_SYS_setreuid */
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{ -1, -1, NULL}
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};
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struct syscallaction syscalls_ultrix[] = {
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{ 11, SYSTR_POLICY_ASK, NULL}, /* ULTRIX_SYS_execv */
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{ 23, SYSTR_POLICY_ASK, NULL}, /* ULTRIX_SYS_setuid */
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{ 59, SYSTR_POLICY_ASK, check_exec}, /* ULTRIX_SYS_execve */
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{ 126, SYSTR_POLICY_ASK, NULL}, /* ULTRIX_SYS_setreuid */
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{ -1, -1, NULL}
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};
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struct syscallaction syscalls_irix[] = {
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{ 11, SYSTR_POLICY_ASK, NULL}, /* IRIX_SYS_execv */
|
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{ 23, SYSTR_POLICY_ASK, NULL}, /* IRIX_SYS_setuid */
|
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{ 59, SYSTR_POLICY_ASK, check_exec}, /* IRIX_SYS_execve */
|
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{ 124, SYSTR_POLICY_ASK, NULL}, /* IRIX_SYS_setreuid */
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{ -1, -1, NULL}
|
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};
|
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|
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struct syscallaction syscalls_darwin[] = {
|
||||
{ 23, SYSTR_POLICY_ASK, NULL}, /* DARWIN_SYS_setuid */
|
||||
{ 59, SYSTR_POLICY_ASK, check_exec}, /* DARWIN_SYS_execve */
|
||||
{ 126, SYSTR_POLICY_ASK, NULL}, /* DARWIN_SYS_setreuid */
|
||||
{ 183, SYSTR_POLICY_ASK, NULL}, /* DARWIN_SYS_seteuid */
|
||||
{ -1, -1, NULL}
|
||||
};
|
||||
|
||||
struct emulation {
|
||||
const char *name;
|
||||
struct syscallaction *action;
|
||||
} emulations[] = {
|
||||
{ "bsdos", syscalls_bsdos },
|
||||
#if defined(__darwin__) || defined(__APPLE__)
|
||||
{ "native", syscalls_darwin },
|
||||
#else
|
||||
{ "darwin", syscalls_darwin },
|
||||
#endif
|
||||
#ifdef __FreeBSD__
|
||||
{ "native", syscalls_freebsd },
|
||||
#else
|
||||
{ "freebsd", syscalls_freebsd },
|
||||
#endif
|
||||
{ "hpux", syscalls_hpux },
|
||||
{ "ibsc2", syscalls_ibsc2 },
|
||||
{ "irix", syscalls_irix },
|
||||
#if defined(__linux__)
|
||||
{ "native", syscalls_linux },
|
||||
#else
|
||||
{ "linux", syscalls_linux },
|
||||
#endif
|
||||
#ifdef __NetBSD__
|
||||
{ "native", syscalls_netbsd },
|
||||
#else
|
||||
{ "netbsd", syscalls_netbsd },
|
||||
#endif
|
||||
{ "netbsd32", syscalls_netbsd },
|
||||
#ifdef __OpenBSD__
|
||||
{ "native", syscalls_openbsd },
|
||||
#else
|
||||
{ "openbsd", syscalls_openbsd },
|
||||
#endif
|
||||
{ "osf1", syscalls_osf1 },
|
||||
{ "pecoff", syscalls_netbsd },
|
||||
{ "sunos", syscalls_sunos },
|
||||
{ "sunos32", syscalls_sunos },
|
||||
{ "svr4", syscalls_svr4 },
|
||||
{ "svr4_32", syscalls_svr4 },
|
||||
{ "ultrix", syscalls_ultrix },
|
||||
{ NULL, NULL }
|
||||
};
|
||||
Reference in New Issue
Block a user