[compiler-rt] [compiler-rt][sanitizer-common] intercept getaddrinfo_a for Linux. (PR #123167)

[David CARLIER via llvm-commits]

https://github.com/devnexen created https://github.com/llvm/llvm-project/pull/123167

None

>From fbf4bf1aa6e1689f49ec92ae700a7e7745f17f82 Mon Sep 17 00:00:00 2001
From: David Carlier <devnexen at gmail.com>
Date: Thu, 16 Jan 2025 06:56:14 +0000
Subject: [PATCH] [compiler-rt][sanitizer-common] intercept getaddrinfo_a for
 Linux.

---
 .../sanitizer_common_interceptors.inc         | 47 +++++++++++++++++++
 .../sanitizer_platform_interceptors.h         |  1 +
 .../sanitizer_platform_limits_posix.h         |  9 ++++
 3 files changed, 57 insertions(+)

diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_common_interceptors.inc b/compiler-rt/lib/sanitizer_common/sanitizer_common_interceptors.inc
index 24a8a2d4dc55b4..94d1eb03b7f96a 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_common_interceptors.inc
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_common_interceptors.inc
@@ -10263,6 +10263,52 @@ INTERCEPTOR(SSIZE_T, freadlink, int fd, char *buf, SIZE_T bufsiz) {
 #  define INIT_FREADLINK
 #endif
 
+#if SANITIZER_INTERCEPT_GETADDRINFO_A
+INTERCEPTOR(int, getaddrinfo_a, int mode, struct __sanitizer_gaicb *list, int num,
+            void* sevp) {
+  void *ctx;
+  COMMON_INTERCEPTOR_ENTER(ctx, getaddrinfo_a, mode, list, num, sevp);
+  if (sevp) {
+    COMMON_INTERCEPTOR_READ_RANGE(ctx, sevp, struct_sigevent_sz);
+  }
+  if (list) {
+    for (int i = 0; i < num; i ++) {
+      struct __sanitizer_gaicb *cb = list[i];
+      COMMON_INTERCEPTOR_READ_RANGE(ctx, cb, sizeof(__sanitizer_gaicb));
+      if (cb->ar_name)
+        COMMON_INTERCEPTOR_READ_RANGE(ctx, cb->ar_name, internal_strlen(cb->ar_name) + 1);
+      if (cb->ar_service)
+        COMMON_INTERCEPTOR_READ_RANGE(ctx, cb->ar_service, internal_strlen(cb->ar_service) + 1);
+      if (cb->ar_request) {
+        COMMON_INTERCEPTOR_READ_RANGE(ctx, cb->ar_request, sizeof(__sanitizer_addrinfo));
+      }
+    }
+  }
+
+  int res = REAL(getaddrinfo_a)(mode, list, num, sevp);
+  if (res == 0 && list) {
+    for (int i = 0; i < num; i ++) {
+      struct __sanitizer_addrinfo *result = list[i]->ar_result;
+      if (result) {
+        while (result) {
+          COMMON_INTERCEPTOR_WRITE_RANGE(ctx, result, sizeof(__sanitizer_addrinfo));
+	  if (result->ai_addr)
+            COMMON_INTERCEPTOR_WRITE_RANGE(ctx, result->ai_addr, result->ai_addrlen);
+	  if (result->ai_canonname)
+            COMMON_INTERCEPTOR_WRITE_RANGE(ctx, result->ai_canonname, internal_strlen(result->ai_canonname) + 1);
+	  result = result->ai_next;
+	}
+      }
+    }
+  }
+
+  return res;
+}
+#  define INIT_GETADDRINFO_A COMMON_INTERCEPT_FUNCTION(getaddrinfo_a)
+#else
+#  define INIT_GETADDRINFO_A
+#endif
+
 #include "sanitizer_common_interceptors_netbsd_compat.inc"
 
 namespace __sanitizer {
@@ -10585,6 +10631,7 @@ static void InitializeCommonInterceptors() {
   INIT_PREADV2;
   INIT_PWRITEV2;
   INIT_FREADLINK;
+  INIT_GETADDRINFO_A;
 
   INIT___PRINTF_CHK;
 }
diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_platform_interceptors.h b/compiler-rt/lib/sanitizer_common/sanitizer_platform_interceptors.h
index febd233bb1e3c0..4f8bde076f8483 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_platform_interceptors.h
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_platform_interceptors.h
@@ -640,6 +640,7 @@ SANITIZER_WEAK_IMPORT void *aligned_alloc(__sanitizer::usize __alignment,
 #  define SI_MAC_OS_DEPLOYMENT_MIN_13_00 0
 #endif
 #define SANITIZER_INTERCEPT_FREADLINK (SI_MAC && SI_MAC_OS_DEPLOYMENT_MIN_13_00)
+#define SANITIZER_GETADDRINFO_A SI_LINUX
 // This macro gives a way for downstream users to override the above
 // interceptor macros irrespective of the platform they are on. They have
 // to do two things:
diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_platform_limits_posix.h b/compiler-rt/lib/sanitizer_common/sanitizer_platform_limits_posix.h
index 7e62dc0e0523ec..6c54d1f564cfca 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_platform_limits_posix.h
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_platform_limits_posix.h
@@ -788,6 +788,15 @@ struct __sanitizer_addrinfo {
   struct __sanitizer_addrinfo *ai_next;
 };
 
+#if SANITIZER_LINUX
+struct __sanitizer_gaicb {
+  const char *ar_name;
+  const char *ar_service;
+  const struct __sanitizer_addrinfo ar_request;
+  struct __sanitizer_addrinfo *ar_result;
+};
+#endif
+
 struct __sanitizer_hostent {
   char *h_name;
   char **h_aliases;