Impove struct cmsghdr decoding
Print all cmsghdr structures in msg_control array,
not just the first one.
Change output format to be consistent with other parts of strace
where structures and arrays are printed.
Implement decoder for SCM_SECURITY message type.
* net.c (print_scm_rights, print_scm_creds, print_scm_security):
New functions.
(printcmsghdr): Use them. Iterate over all members of the array.
* xlat/scmvals.in: Add SCM_SECURITY.
* tests/scm_rights.c (main): Pass one more descriptor to the receiver.
Set SO_PASSCRED on the receiver part. Reserve enough space to receive
SCM_CREDENTIALS and SCM_RIGHTS.
* tests/scm_rights-fd.test: Update.
diff --git a/net.c b/net.c
index c235116..829f3ad 100644
--- a/net.c
+++ b/net.c
@@ -339,7 +339,10 @@
}
#if HAVE_SENDMSG
-#include "xlat/scmvals.h"
+# ifndef SCM_SECURITY
+# define SCM_SECURITY 0x03
+# endif
+# include "xlat/scmvals.h"
#if SUPPORTED_PERSONALITIES > 1 && SIZEOF_LONG > 4
struct cmsghdr32 {
@@ -350,91 +353,152 @@
#endif
typedef union {
- char *buf;
+ char *ptr;
struct cmsghdr *cmsg;
#if SUPPORTED_PERSONALITIES > 1 && SIZEOF_LONG > 4
struct cmsghdr32 *cmsg32;
#endif
} union_cmsghdr;
-static void
-printcmsghdr(struct tcb *tcp, unsigned long addr, unsigned long len)
+static bool
+print_scm_rights(struct tcb *tcp, size_t cmsg_size, char *ptr, size_t cmsg_len)
{
- union_cmsghdr u;
- size_t cmsg_size;
- unsigned long cmsg_len;
- int cmsg_level;
- int cmsg_type;
+ if (cmsg_size + sizeof(int) > cmsg_len)
+ return false;
- cmsg_size =
+ int *fds = (int *) (ptr + cmsg_size);
+ bool seen = false;
+
+ tprints(", [");
+ while ((char *) fds < (ptr + cmsg_len)) {
+ if (seen)
+ tprints(", ");
+ else
+ seen = true;
+ printfd(tcp, *fds++);
+ }
+ tprints("]}");
+ return true;
+}
+
+static bool
+print_scm_creds(struct tcb *tcp, size_t cmsg_size, char *ptr, size_t cmsg_len)
+{
+ if (cmsg_size + sizeof(struct ucred) > cmsg_len)
+ return false;
+
+ const struct ucred *uc = (void *) (ptr + cmsg_size);
+
+ tprintf(", {pid=%u, uid=%u, gid=%u}}",
+ (unsigned) uc->pid, (unsigned) uc->uid, (unsigned) uc->gid);
+ return true;
+}
+
+static bool
+print_scm_security(struct tcb *tcp, size_t cmsg_size, char *ptr, size_t cmsg_len)
+{
+ if (cmsg_size + sizeof(char) > cmsg_len)
+ return false;
+
+ const char *label = (const char *) (ptr + cmsg_size);
+ const size_t label_len = cmsg_len - cmsg_size;
+ char *outstr;
+ const size_t alloc_len = 4 * label_len + 3;
+
+ if (label_len != alloc_len / 4 ||
+ !(outstr = malloc(alloc_len)))
+ return false;
+
+ string_quote(label, outstr, 0, label_len);
+ tprintf(", %s}", outstr);
+
+ free(outstr);
+ return true;
+}
+
+static void
+printcmsghdr(struct tcb *tcp, unsigned long addr, size_t len)
+{
+ const size_t cmsg_size =
#if SUPPORTED_PERSONALITIES > 1 && SIZEOF_LONG > 4
(current_wordsize < sizeof(long)) ? sizeof(struct cmsghdr32) :
#endif
sizeof(struct cmsghdr);
- u.buf = len < cmsg_size ? NULL : malloc(len);
- if (!u.buf || umoven(tcp, addr, len, u.buf) < 0) {
+ char *buf = len < cmsg_size ? NULL : malloc(len);
+ if (!buf || umoven(tcp, addr, len, buf) < 0) {
tprintf(", msg_control=%#lx", addr);
- free(u.buf);
+ free(buf);
return;
}
- cmsg_len =
+ union_cmsghdr u = { .ptr = buf };
+
+ tprints(", [");
+ while (len >= cmsg_size) {
+ size_t cmsg_len =
#if SUPPORTED_PERSONALITIES > 1 && SIZEOF_LONG > 4
- (current_wordsize < sizeof(long)) ? u.cmsg32->cmsg_len :
+ (current_wordsize < sizeof(long)) ? u.cmsg32->cmsg_len :
#endif
- u.cmsg->cmsg_len;
- cmsg_level =
+ u.cmsg->cmsg_len;
+ int cmsg_level =
#if SUPPORTED_PERSONALITIES > 1 && SIZEOF_LONG > 4
- (current_wordsize < sizeof(long)) ? u.cmsg32->cmsg_level :
+ (current_wordsize < sizeof(long)) ? u.cmsg32->cmsg_level :
#endif
- u.cmsg->cmsg_level;
- cmsg_type =
+ u.cmsg->cmsg_level;
+ int cmsg_type =
#if SUPPORTED_PERSONALITIES > 1 && SIZEOF_LONG > 4
- (current_wordsize < sizeof(long)) ? u.cmsg32->cmsg_type :
+ (current_wordsize < sizeof(long)) ? u.cmsg32->cmsg_type :
#endif
- u.cmsg->cmsg_type;
+ u.cmsg->cmsg_type;
- tprintf(", {cmsg_len=%lu, cmsg_level=", cmsg_len);
- printxval(socketlayers, cmsg_level, "SOL_???");
- tprints(", cmsg_type=");
+ if (u.ptr != buf)
+ tprints(", ");
+ tprintf("{cmsg_len=%lu, cmsg_level=", (unsigned long) cmsg_len);
+ printxval(socketlayers, cmsg_level, "SOL_???");
+ tprints(", cmsg_type=");
- if (cmsg_len > len)
- cmsg_len = len;
+ if (cmsg_len > len)
+ cmsg_len = len;
- if (cmsg_level == SOL_SOCKET) {
- printxval(scmvals, cmsg_type, "SCM_???");
-
- if (cmsg_type == SCM_RIGHTS
- && cmsg_size + sizeof(int) <= cmsg_len) {
- int *fds = (int *) (u.buf + cmsg_size);
- int first = 1;
-
- tprints(", {");
- while ((char *) fds < (u.buf + cmsg_len)) {
- if (!first)
- tprints(", ");
- printfd(tcp, *fds++);
- first = 0;
+ if (cmsg_level == SOL_SOCKET) {
+ printxval(scmvals, cmsg_type, "SCM_???");
+ switch (cmsg_type) {
+ case SCM_RIGHTS:
+ if (print_scm_rights(tcp, cmsg_size, u.ptr, cmsg_len))
+ goto next_cmsg;
+ break;
+ case SCM_CREDENTIALS:
+ if (print_scm_creds(tcp, cmsg_size, u.ptr, cmsg_len))
+ goto next_cmsg;
+ break;
+ case SCM_SECURITY:
+ if (print_scm_security(tcp, cmsg_size, u.ptr, cmsg_len))
+ goto next_cmsg;
+ break;
}
- tprints("}}");
- free(u.buf);
- return;
+ } else {
+ tprintf("%u", cmsg_type);
}
- if (cmsg_type == SCM_CREDENTIALS
- && cmsg_size + sizeof(struct ucred) <= cmsg_len) {
- struct ucred *uc = (void *) (u.buf + cmsg_size);
-
- tprintf("{pid=%ld, uid=%ld, gid=%ld}}",
- (long)uc->pid, (long)uc->uid, (long)uc->gid);
- free(u.buf);
- return;
+ tprints(", ...}");
+next_cmsg:
+ if (cmsg_len < cmsg_size) {
+ len -= cmsg_size;
+ break;
}
- } else {
- tprintf("%u", cmsg_type);
+ cmsg_len = (cmsg_len + current_wordsize - 1) &
+ (size_t) ~(current_wordsize - 1);
+ if (cmsg_len >= len) {
+ len = 0;
+ break;
+ }
+ u.ptr += cmsg_len;
+ len -= cmsg_len;
}
- free(u.buf);
- tprints(", ...}");
+ if (len)
+ tprints(", ...");
+ tprints("]");
+ free(buf);
}
static void