log: fix repeated invocation of vsnprintf()/vaprintf() in log_struct()

https://bugs.freedesktop.org/show_bug.cgi?id=55213

diff --git a/src/nspawn/nspawn.c b/src/nspawn/nspawn.c
index 959df4e0d836f79cbd4fb7fa955f1ac4ae2a57bd..5cac32cd8c84312ce28b97cfd515ecab1c2a7dba 100644 (file)
--- a/src/nspawn/nspawn.c
+++ b/src/nspawn/nspawn.c
@@ -1307,6 +1307,12 @@ int main(int argc, char *argv[]) {
 
                         if (arg_user) {
 
+                                /* Note that this resolves user names
+                                 * inside the container, and hence
+                                 * accesses the NSS modules from the
+                                 * container and not the host. This is
+                                 * a bit weird... */
+
                                 if (get_user_creds((const char**)&arg_user, &uid, &gid, &home, NULL) < 0) {
                                         log_error("get_user_creds() failed: %m");
                                         goto child_fail;

diff --git a/src/shared/log.c b/src/shared/log.c
index b61845859f3cca5300b7750fa812a564cd2c3913..63578683ab6575b73df32ddd9164893471d5f186 100644 (file)
--- a/src/shared/log.c
+++ b/src/shared/log.c
@@ -27,6 +27,7 @@
 #include <sys/socket.h>
 #include <sys/un.h>
 #include <stddef.h>
+#include <printf.h>
 
 #include "log.h"
 #include "util.h"
@@ -705,11 +706,23 @@ int log_struct_internal(
                 va_start(ap, format);
                 while (format && n + 1 < ELEMENTSOF(iovec)) {
                         char *buf;
+                        va_list aq;
 
-                        if (vasprintf(&buf, format, ap) < 0) {
+                        /* We need to copy the va_list structure,
+                         * since vasprintf() leaves it afterwards at
+                         * an undefined location */
+
+                        va_copy(aq, ap);
+                        if (vasprintf(&buf, format, aq) < 0) {
+                                va_end(aq);
                                 r = -ENOMEM;
                                 goto finish;
                         }
+                        va_end(aq);
+
+                        /* Now, jump enough ahead, so that we point to
+                         * the next format string */
+                        VA_FORMAT_ADVANCE(format, ap);
 
                         IOVEC_SET_STRING(iovec[n++], buf);
 
@@ -742,8 +755,11 @@ int log_struct_internal(
 
                 va_start(ap, format);
                 while (format) {
+                        va_list aq;
 
-                        vsnprintf(buf, sizeof(buf), format, ap);
+                        va_copy(aq, ap);
+                        vsnprintf(buf, sizeof(buf), format, aq);
+                        va_end(aq);
                         char_array_0(buf);
 
                         if (startswith(buf, "MESSAGE=")) {
@@ -751,6 +767,8 @@ int log_struct_internal(
                                 break;
                         }
 
+                        VA_FORMAT_ADVANCE(format, ap);
+
                         format = va_arg(ap, char *);
                 }
                 va_end(ap);

diff --git a/src/shared/macro.h b/src/shared/macro.h
index c7ce7c87d096079fdc1ff0f6c3a60582a2407197..0dd210afa7c419dcf362281134f325ed3542616b 100644 (file)
--- a/src/shared/macro.h
+++ b/src/shared/macro.h
@@ -193,4 +193,47 @@ static inline size_t IOVEC_INCREMENT(struct iovec *i, unsigned n, size_t k) {
 #define _cleanup_closedir_ __attribute__((cleanup(closedirp)))
 #define _cleanup_umask_ __attribute__((cleanup(umaskp)))
 
+#define VA_FORMAT_ADVANCE(format, ap) do {                              \
+        int _argtypes[64];                                              \
+        size_t _i, _k;                                                  \
+        _k = parse_printf_format((format), ELEMENTSOF(_argtypes), _argtypes); \
+        for (_i = 0; _i < _k; _i++) {                                   \
+                if (_argtypes[_i] & PA_FLAG_PTR)  {                     \
+                        (void) va_arg(ap, void*);                       \
+                        continue;                                       \
+                }                                                       \
+                                                                        \
+                switch (_argtypes[_i]) {                                \
+                case PA_INT:                                            \
+                case PA_INT|PA_FLAG_SHORT:                              \
+                case PA_CHAR:                                           \
+                        (void) va_arg(ap, int);                         \
+                        break;                                          \
+                case PA_INT|PA_FLAG_LONG:                               \
+                        (void) va_arg(ap, long int);                    \
+                        break;                                          \
+                case PA_INT|PA_FLAG_LONG_LONG:                          \
+                        (void) va_arg(ap, long long int);               \
+                        break;                                          \
+                case PA_WCHAR:                                          \
+                        (void) va_arg(ap, wchar_t);                     \
+                        break;                                          \
+                case PA_WSTRING:                                        \
+                case PA_STRING:                                         \
+                case PA_POINTER:                                        \
+                        (void) va_arg(ap, void*);                       \
+                        break;                                          \
+                case PA_FLOAT:                                          \
+                case PA_DOUBLE:                                         \
+                        (void) va_arg(ap, double);                      \
+                        break;                                          \
+                case PA_DOUBLE|PA_FLAG_LONG_DOUBLE:                     \
+                        (void) va_arg(ap, long double);                 \
+                        break;                                          \
+                default:                                                \
+                        assert_not_reached("Unknown format string argument."); \
+                }                                                       \
+        }                                                               \
+} while(false)
+
 #include "log.h"

diff --git a/src/test/test-log.c b/src/test/test-log.c
index cc924fa57ba3e10668bda53a7deaa537e364e3ef..8dc3d5383f387bf976e4ee3804c56ce8b983b66b 100644 (file)
--- a/src/test/test-log.c
+++ b/src/test/test-log.c
@@ -42,5 +42,12 @@ int main(int argc, char* argv[]) {
                    "SERVICE=foobar",
                    NULL);
 
+        log_struct(LOG_INFO,
+                   "MESSAGE=Foobar PID=%lu", (unsigned long) getpid(),
+                   "FORMAT_STR_TEST=1=%i A=%c 2=%hi 3=%li 4=%lli 1=%p foo=%s 2.5=%g 3.5=%g 4.5=%Lg",
+                   (int) 1, 'A', (short) 2, (long int) 3, (long long int) 4, (void*) 1, "foo", (float) 2.5f, (double) 3.5, (long double) 4.5,
+                   "SUFFIX=GOT IT",
+                   NULL);
+
         return 0;
 }