Merge pull request #29644 from poettering/json-iovec

add iovec/base64 json helpers and other iovec tweaks

src/basic/iovec-util.h

@@ -5,6 +5,7 @@
 #include <sys/types.h>
 #include <sys/uio.h>
 
+#include "alloc-util.h"
 #include "macro.h"
 
 size_t iovec_total_size(const struct iovec *i, size_t n);
@@ -20,6 +21,27 @@ bool iovec_increment(struct iovec *i, size_t n, size_t k);
                 IOVEC_MAKE((char*) _s, strlen(_s));     \
         })
 
+#define TAKE_IOVEC(p) TAKE_GENERIC((p), struct iovec, IOVEC_NULL)
+
+static inline void iovec_done(struct iovec *iovec) {
+        /* A _cleanup_() helper that frees the iov_base in the iovec */
+        assert(iovec);
+
+        iovec->iov_base = mfree(iovec->iov_base);
+        iovec->iov_len = 0;
+}
+
+static inline void iovec_done_erase(struct iovec *iovec) {
+        assert(iovec);
+
+        iovec->iov_base = erase_and_free(iovec->iov_base);
+        iovec->iov_len = 0;
+}
+
+static inline bool iovec_is_set(const struct iovec *iov) {
+        return iov && iov->iov_len > 0 && iov->iov_base;
+}
+
 char* set_iovec_string_field(struct iovec *iovec, size_t *n_iovec, const char *field, const char *value);
 char* set_iovec_string_field_free(struct iovec *iovec, size_t *n_iovec, const char *field, char *value);
 

src/partition/repart.c

@@ -268,8 +268,7 @@ typedef struct Partition {
         int read_only;
         int growfs;
 
-        uint8_t *roothash;
-        size_t roothash_size;
+        struct iovec roothash;
 
         char *split_name_format;
         char *split_path;
@@ -418,7 +417,7 @@ static Partition* partition_free(Partition *p) {
         strv_free(p->subvolumes);
         free(p->verity_match_key);
 
-        free(p->roothash);
+        iovec_done(&p->roothash);
 
         free(p->split_name_format);
         unlink_and_free(p->split_path);
@@ -2824,7 +2823,7 @@ static int context_dump_partitions(Context *context) {
                 if (p->verity != VERITY_OFF) {
                         Partition *hp = p->verity == VERITY_HASH ? p : p->siblings[VERITY_HASH];
 
-                        rh = hp->roothash ? hexmem(hp->roothash, hp->roothash_size) : strdup("TBD");
+                        rh = iovec_is_set(&hp->roothash) ? hexmem(hp->roothash.iov_base, hp->roothash.iov_len) : strdup("TBD");
                         if (!rh)
                                 return log_oom();
                 }
@@ -3101,7 +3100,7 @@ static int context_dump_partition_bar(Context *context) {
 
 static bool context_has_roothash(Context *context) {
         LIST_FOREACH(partitions, p, context->partitions)
-                if (p->roothash)
+                if (iovec_is_set(&p->roothash))
                         return true;
 
         return false;
@@ -3986,8 +3985,6 @@ static int partition_format_verity_hash(
         _cleanup_(partition_target_freep) PartitionTarget *t = NULL;
         _cleanup_(sym_crypt_freep) struct crypt_device *cd = NULL;
         _cleanup_free_ char *hint = NULL;
-        _cleanup_free_ uint8_t *rh = NULL;
-        size_t rhs;
         int r;
 
         assert(context);
@@ -4066,30 +4063,31 @@ static int partition_format_verity_hash(
         r = sym_crypt_get_volume_key_size(cd);
         if (r < 0)
                 return log_error_errno(r, "Failed to determine verity root hash size of partition %s: %m", strna(hint));
-        rhs = (size_t) r;
 
-        rh = malloc(rhs);
-        if (!rh)
+        _cleanup_(iovec_done) struct iovec rh = {
+                .iov_base = malloc(r),
+                .iov_len = r,
+        };
+        if (!rh.iov_base)
                 return log_oom();
 
-        r = sym_crypt_volume_key_get(cd, CRYPT_ANY_SLOT, (char *) rh, &rhs, NULL, 0);
+        r = sym_crypt_volume_key_get(cd, CRYPT_ANY_SLOT, (char *) rh.iov_base, &rh.iov_len, NULL, 0);
         if (r < 0)
                 return log_error_errno(r, "Failed to get verity root hash of partition %s: %m", strna(hint));
 
-        assert(rhs >= sizeof(sd_id128_t) * 2);
+        assert(rh.iov_len >= sizeof(sd_id128_t) * 2);
 
         if (!dp->new_uuid_is_set) {
-                memcpy_safe(dp->new_uuid.bytes, rh, sizeof(sd_id128_t));
+                memcpy_safe(dp->new_uuid.bytes, rh.iov_base, sizeof(sd_id128_t));
                 dp->new_uuid_is_set = true;
         }
 
         if (!p->new_uuid_is_set) {
-                memcpy_safe(p->new_uuid.bytes, rh + rhs - sizeof(sd_id128_t), sizeof(sd_id128_t));
+                memcpy_safe(p->new_uuid.bytes, (uint8_t*) rh.iov_base + (rh.iov_len - sizeof(sd_id128_t)), sizeof(sd_id128_t));
                 p->new_uuid_is_set = true;
         }
 
-        p->roothash = TAKE_PTR(rh);
-        p->roothash_size = rhs;
+        p->roothash = TAKE_IOVEC(rh);
 
         return 0;
 #else
@@ -4098,10 +4096,8 @@ static int partition_format_verity_hash(
 }
 
 static int sign_verity_roothash(
-                const uint8_t *roothash,
-                size_t roothash_size,
-                uint8_t **ret_signature,
-                size_t *ret_signature_size) {
+                const struct iovec *roothash,
+                struct iovec *ret_signature) {
 
 #if HAVE_OPENSSL
         _cleanup_(BIO_freep) BIO *rb = NULL;
@@ -4111,11 +4107,10 @@ static int sign_verity_roothash(
         int sigsz;
 
         assert(roothash);
-        assert(roothash_size > 0);
+        assert(iovec_is_set(roothash));
         assert(ret_signature);
-        assert(ret_signature_size);
 
-        hex = hexmem(roothash, roothash_size);
+        hex = hexmem(roothash->iov_base, roothash->iov_len);
         if (!hex)
                 return log_oom();
 
@@ -4133,8 +4128,8 @@ static int sign_verity_roothash(
                 return log_error_errno(SYNTHETIC_ERRNO(EIO), "Failed to convert PKCS7 signature to DER: %s",
                                        ERR_error_string(ERR_get_error(), NULL));
 
-        *ret_signature = TAKE_PTR(sig);
-        *ret_signature_size = sigsz;
+        ret_signature->iov_base = TAKE_PTR(sig);
+        ret_signature->iov_len = sigsz;
 
         return 0;
 #else
@@ -4144,11 +4139,10 @@ static int sign_verity_roothash(
 
 static int partition_format_verity_sig(Context *context, Partition *p) {
         _cleanup_(json_variant_unrefp) JsonVariant *v = NULL;
-        _cleanup_free_ uint8_t *sig = NULL;
+        _cleanup_(iovec_done) struct iovec sig = IOVEC_NULL;
         _cleanup_free_ char *text = NULL, *hint = NULL;
         Partition *hp;
         uint8_t fp[X509_FINGERPRINT_SIZE];
-        size_t sigsz = 0; /* avoid false maybe-uninitialized warning */
         int whole_fd, r;
 
         assert(p->verity == VERITY_SIG);
@@ -4168,7 +4162,7 @@ static int partition_format_verity_sig(Context *context, Partition *p) {
 
         assert_se((whole_fd = fdisk_get_devfd(context->fdisk_context)) >= 0);
 
-        r = sign_verity_roothash(hp->roothash, hp->roothash_size, &sig, &sigsz);
+        r = sign_verity_roothash(&hp->roothash, &sig);
         if (r < 0)
                 return r;
 
@@ -4178,12 +4172,12 @@ static int partition_format_verity_sig(Context *context, Partition *p) {
 
         r = json_build(&v,
                         JSON_BUILD_OBJECT(
-                                JSON_BUILD_PAIR("rootHash", JSON_BUILD_HEX(hp->roothash, hp->roothash_size)),
+                                JSON_BUILD_PAIR("rootHash", JSON_BUILD_HEX(hp->roothash.iov_base, hp->roothash.iov_len)),
                                 JSON_BUILD_PAIR(
                                         "certificateFingerprint",
                                         JSON_BUILD_HEX(fp, sizeof(fp))
                                 ),
-                                JSON_BUILD_PAIR("signature", JSON_BUILD_BASE64(sig, sigsz))
+                                JSON_BUILD_PAIR("signature", JSON_BUILD_IOVEC_BASE64(&sig))
                         )
         );
         if (r < 0)

src/shared/json.c

@@ -3790,6 +3790,34 @@ int json_buildv(JsonVariant **ret, va_list ap) {
                         break;
                 }
 
+                case _JSON_BUILD_IOVEC_BASE64: {
+                        const struct iovec *iov;
+
+                        if (!IN_SET(current->expect, EXPECT_TOPLEVEL, EXPECT_OBJECT_VALUE, EXPECT_ARRAY_ELEMENT)) {
+                                r = -EINVAL;
+                                goto finish;
+                        }
+
+                        iov = ASSERT_PTR(va_arg(ap, const struct iovec*));
+
+                        if (current->n_suppress == 0) {
+                                r = json_variant_new_base64(&add, iov->iov_base, iov->iov_len);
+                                if (r < 0)
+                                        goto finish;
+                        }
+
+                        n_subtract = 1;
+
+                        if (current->expect == EXPECT_TOPLEVEL)
+                                current->expect = EXPECT_END;
+                        else if (current->expect == EXPECT_OBJECT_VALUE)
+                                current->expect = EXPECT_OBJECT_KEY;
+                        else
+                                assert(current->expect == EXPECT_ARRAY_ELEMENT);
+
+                        break;
+                }
+
                 case _JSON_BUILD_ID128:
                 case _JSON_BUILD_UUID: {
                         const sd_id128_t *id;
@@ -4863,6 +4891,24 @@ int json_dispatch_unsupported(const char *name, JsonVariant *variant, JsonDispat
         return json_log(variant, flags, SYNTHETIC_ERRNO(EINVAL), "JSON field '%s' is not allowed in this object.", strna(name));
 }
 
+int json_dispatch_unbase64_iovec(const char *name, JsonVariant *variant, JsonDispatchFlags flags, void *userdata) {
+        _cleanup_free_ void *buffer = NULL;
+        struct iovec *iov = ASSERT_PTR(userdata);
+        size_t sz;
+        int r;
+
+        if (!json_variant_is_string(variant))
+                return json_log(variant, flags, SYNTHETIC_ERRNO(EINVAL), "JSON field '%s' is not a string.", strna(name));
+
+        r = json_variant_unbase64(variant, &buffer, &sz);
+        if (r < 0)
+                return json_log(variant, flags, r, "JSON field '%s' is not valid Base64 data.", strna(name));
+
+        free_and_replace(iov->iov_base, buffer);
+        iov->iov_len = sz;
+        return 0;
+}
+
 static int json_cmp_strings(const void *x, const void *y) {
         JsonVariant *const *a = x, *const *b = y;
 

src/shared/json.h

@@ -268,6 +268,7 @@ enum {
         _JSON_BUILD_STRV,
         _JSON_BUILD_STRV_ENV_PAIR,
         _JSON_BUILD_BASE64,
+        _JSON_BUILD_IOVEC_BASE64,
         _JSON_BUILD_BASE32HEX,
         _JSON_BUILD_HEX,
         _JSON_BUILD_OCTESCAPE,
@@ -311,6 +312,7 @@ typedef int (*JsonBuildCallback)(JsonVariant **ret, const char *name, void *user
 #define JSON_BUILD_STRV(l) _JSON_BUILD_STRV, (char**) { l }
 #define JSON_BUILD_STRV_ENV_PAIR(l) _JSON_BUILD_STRV_ENV_PAIR, (char**) { l }
 #define JSON_BUILD_BASE64(p, n) _JSON_BUILD_BASE64, (const void*) { p }, (size_t) { n }
+#define JSON_BUILD_IOVEC_BASE64(iov) _JSON_BUILD_IOVEC_BASE64, (const struct iovec*) { iov }
 #define JSON_BUILD_BASE32HEX(p, n) _JSON_BUILD_BASE32HEX, (const void*) { p }, (size_t) { n }
 #define JSON_BUILD_HEX(p, n) _JSON_BUILD_HEX, (const void*) { p }, (size_t) { n }
 #define JSON_BUILD_OCTESCAPE(p, n) _JSON_BUILD_OCTESCAPE, (const void*) { p }, (size_t) { n }
@@ -341,6 +343,7 @@ typedef int (*JsonBuildCallback)(JsonVariant **ret, const char *name, void *user
 #define JSON_BUILD_PAIR_LITERAL(name, l) JSON_BUILD_PAIR(name, JSON_BUILD_LITERAL(l))
 #define JSON_BUILD_PAIR_STRV(name, l) JSON_BUILD_PAIR(name, JSON_BUILD_STRV(l))
 #define JSON_BUILD_PAIR_BASE64(name, p, n) JSON_BUILD_PAIR(name, JSON_BUILD_BASE64(p, n))
+#define JSON_BUILD_PAIR_IOVEC_BASE64(name, iov) JSON_BUILD_PAIR(name, JSON_BUILD_IOVEC_BASE64(iov))
 #define JSON_BUILD_PAIR_HEX(name, p, n) JSON_BUILD_PAIR(name, JSON_BUILD_HEX(p, n))
 #define JSON_BUILD_PAIR_ID128(name, id) JSON_BUILD_PAIR(name, JSON_BUILD_ID128(id))
 #define JSON_BUILD_PAIR_UUID(name, id) JSON_BUILD_PAIR(name, JSON_BUILD_UUID(id))
@@ -412,6 +415,7 @@ int json_dispatch_uid_gid(const char *name, JsonVariant *variant, JsonDispatchFl
 int json_dispatch_user_group_name(const char *name, JsonVariant *variant, JsonDispatchFlags flags, void *userdata);
 int json_dispatch_id128(const char *name, JsonVariant *variant, JsonDispatchFlags flags, void *userdata);
 int json_dispatch_unsupported(const char *name, JsonVariant *variant, JsonDispatchFlags flags, void *userdata);
+int json_dispatch_unbase64_iovec(const char *name, JsonVariant *variant, JsonDispatchFlags flags, void *userdata);
 
 assert_cc(sizeof(uint32_t) == sizeof(unsigned));
 #define json_dispatch_uint json_dispatch_uint32