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Diffstat (limited to 'lib/get_pid.c')
-rw-r--r--lib/get_pid.c90
1 files changed, 81 insertions, 9 deletions
diff --git a/lib/get_pid.c b/lib/get_pid.c
index 383eb69..af3f2f8 100644
--- a/lib/get_pid.c
+++ b/lib/get_pid.c
@@ -10,22 +10,94 @@
#include "prototypes.h"
#include "defines.h"
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
-int get_pid (const char *pidstr, pid_t *pid)
+#include "string/sprintf.h"
+
+
+int
+get_pid(const char *pidstr, pid_t *pid)
{
- long long int val;
- char *endptr;
+ char *end;
+ long long val;
errno = 0;
- val = strtoll (pidstr, &endptr, 10);
+ val = strtoll(pidstr, &end, 10);
if ( ('\0' == *pidstr)
- || ('\0' != *endptr)
- || (ERANGE == errno)
+ || ('\0' != *end)
+ || (0 != errno)
+ || (val < 1)
|| (/*@+longintegral@*/val != (pid_t)val)/*@=longintegral@*/) {
- return 0;
+ return -1;
}
- *pid = (pid_t)val;
- return 1;
+ *pid = val;
+ return 0;
}
+/*
+ * If use passed in fd:4 as an argument, then return the
+ * value '4', the fd to use.
+ * On error, return -1.
+ */
+int get_pidfd_from_fd(const char *pidfdstr)
+{
+ char *end;
+ long long val;
+ struct stat st;
+ dev_t proc_st_dev, proc_st_rdev;
+
+ errno = 0;
+ val = strtoll(pidfdstr, &end, 10);
+ if ( ('\0' == *pidfdstr)
+ || ('\0' != *end)
+ || (0 != errno)
+ || (val < 0)
+ || (/*@+longintegral@*/val != (int)val)/*@=longintegral@*/) {
+ return -1;
+ }
+
+ if (stat("/proc/self/uid_map", &st) < 0) {
+ return -1;
+ }
+
+ proc_st_dev = st.st_dev;
+ proc_st_rdev = st.st_rdev;
+
+ if (fstat(val, &st) < 0) {
+ return -1;
+ }
+
+ if (st.st_dev != proc_st_dev || st.st_rdev != proc_st_rdev) {
+ return -1;
+ }
+
+ return (int)val;
+}
+
+int open_pidfd(const char *pidstr)
+{
+ int proc_dir_fd;
+ char proc_dir_name[32];
+ pid_t target;
+
+ if (get_pid(pidstr, &target) == -1)
+ return -ENOENT;
+
+ /* max string length is 6 + 10 + 1 + 1 = 18, allocate 32 bytes */
+ if (SNPRINTF(proc_dir_name, "/proc/%u/", target) == -1) {
+ fprintf(stderr, "snprintf of proc path failed for %u: %s\n",
+ target, strerror(errno));
+ return -EINVAL;
+ }
+
+ proc_dir_fd = open(proc_dir_name, O_DIRECTORY);
+ if (proc_dir_fd < 0) {
+ fprintf(stderr, _("Could not open proc directory for target %u: %s\n"),
+ target, strerror(errno));
+ return -EINVAL;
+ }
+ return proc_dir_fd;
+}