dhcp-message: introduce dhcp_message_{append,get}_option_parameter_request_list()

These are for DHCP option 55 (parameter request list).

src/libsystemd-network/dhcp-message.c

@@ -11,6 +11,8 @@
 #include "iovec-wrapper.h"
 #include "ip-util.h"
 #include "network-common.h"
+#include "set.h"
+#include "sort-util.h"
 #include "string-util.h"
 
 static sd_dhcp_message* dhcp_message_free(sd_dhcp_message *message) {
@@ -216,6 +218,35 @@ int dhcp_message_append_option_client_id(sd_dhcp_message *message, const sd_dhcp
         return dhcp_message_append_option(message, SD_DHCP_OPTION_CLIENT_IDENTIFIER, id->size, id->raw);
 }
 
+static int cmp_uint8(const uint8_t *a, const uint8_t *b) {
+        assert(a);
+        assert(b);
+
+        return CMP(*a, *b);
+}
+
+int dhcp_message_append_option_parameter_request_list(sd_dhcp_message *message, Set *prl) {
+        assert(message);
+
+        size_t len = set_size(prl);
+        if (len == 0)
+                return 0;
+
+        _cleanup_free_ uint8_t *buf = new(uint8_t, len);
+        if (!buf)
+                return -ENOMEM;
+
+        uint8_t *p = buf;
+        void *q;
+        SET_FOREACH(q, prl)
+                *p++ = PTR_TO_UINT8(q);
+
+        /* Sort the options to make the message reproducible. */
+        typesafe_qsort(buf, len, cmp_uint8);
+
+        return dhcp_message_append_option(message, SD_DHCP_OPTION_PARAMETER_REQUEST_LIST, len, buf);
+}
+
 int dhcp_message_get_option(sd_dhcp_message *message, uint8_t code, size_t length, void *ret) {
         int r;
 
@@ -357,6 +388,33 @@ int dhcp_message_get_option_client_id(sd_dhcp_message *message, sd_dhcp_client_i
         return sd_dhcp_client_id_set_raw(ret, iov.iov_base, iov.iov_len);
 }
 
+int dhcp_message_get_option_parameter_request_list(sd_dhcp_message *message, Set **ret) {
+        int r;
+
+        assert(message);
+
+        _cleanup_(iovec_done) struct iovec iov = {};
+        r = dhcp_message_get_option_alloc(message, SD_DHCP_OPTION_PARAMETER_REQUEST_LIST, &iov);
+        if (r < 0)
+                return r;
+
+        if (!iovec_is_set(&iov))
+                return -ENODATA;
+
+        if (!ret)
+                return 0;
+
+        _cleanup_set_free_ Set *prl = NULL;
+        for (struct iovec i = iov; iovec_is_set(&i); iovec_inc(&i, 1)) {
+                r = set_ensure_put(&prl, /* hash_ops= */ NULL, UINT8_TO_PTR(*(uint8_t*) i.iov_base));
+                if (r < 0)
+                        return r;
+        }
+
+        *ret = TAKE_PTR(prl);
+        return 0;
+}
+
 static int dhcp_message_verify_header(
                 const struct iovec *iov,
                 uint8_t op,

src/libsystemd-network/dhcp-message.h

@@ -40,6 +40,7 @@ int dhcp_message_append_option_address(sd_dhcp_message *message, uint8_t code, c
 int dhcp_message_append_option_addresses(sd_dhcp_message *message, uint8_t code, size_t n_addr, const struct in_addr *addr);
 int dhcp_message_append_option_string(sd_dhcp_message *message, uint8_t code, const char *data);
 int dhcp_message_append_option_client_id(sd_dhcp_message *message, const sd_dhcp_client_id *id);
+int dhcp_message_append_option_parameter_request_list(sd_dhcp_message *message, Set *prl);
 
 int dhcp_message_get_option(sd_dhcp_message *message, uint8_t code, size_t length, void *ret);
 int dhcp_message_get_option_alloc(sd_dhcp_message *message, uint8_t code, struct iovec *ret);
@@ -52,6 +53,7 @@ int dhcp_message_get_option_address(sd_dhcp_message *message, uint8_t code, stru
 int dhcp_message_get_option_addresses(sd_dhcp_message *message, uint8_t code, size_t *ret_n_addr, struct in_addr **ret_addr);
 int dhcp_message_get_option_string(sd_dhcp_message *message, uint8_t code, char **ret);
 int dhcp_message_get_option_client_id(sd_dhcp_message *message, sd_dhcp_client_id *ret);
+int dhcp_message_get_option_parameter_request_list(sd_dhcp_message *message, Set **ret);
 
 int dhcp_message_parse(
                 const struct iovec *iov,

src/libsystemd-network/test-dhcp-message.c

@@ -10,6 +10,7 @@
 #include "iovec-util.h"
 #include "iovec-wrapper.h"
 #include "random-util.h"
+#include "set.h"
 #include "strv.h"
 #include "tests.h"
 
@@ -101,6 +102,12 @@ static void verify_client_id(sd_dhcp_message *m, const sd_dhcp_client_id *expect
         ASSERT_EQ(client_id_compare_func(&id, expected), 0);
 }
 
+static void verify_prl(sd_dhcp_message *m, Set *expected) {
+        _cleanup_set_free_ Set *set = NULL;
+        ASSERT_OK(dhcp_message_get_option_parameter_request_list(m, &set));
+        ASSERT_TRUE(set_equal(set, expected));
+}
+
 TEST(dhcp_message) {
         _cleanup_(sd_dhcp_message_unrefp) sd_dhcp_message *m = NULL;
 
@@ -132,6 +139,10 @@ TEST(dhcp_message) {
                 .size = 7,
         };
 
+        _cleanup_set_free_ Set *prl = NULL;
+        for (uint8_t i = SD_DHCP_OPTION_PRIVATE_BASE; i <= SD_DHCP_OPTION_PRIVATE_LAST; i++)
+                ASSERT_OK(set_ensure_put(&prl, /* hash_ops= */ NULL, UINT_TO_PTR(i)));
+
         const char *vendor_class = "hogehoge";
         char **root_path = STRV_MAKE("/path/to/root", "/hogehoge/foofoo");
 
@@ -206,6 +217,11 @@ TEST(dhcp_message) {
         ASSERT_OK(dhcp_message_append_option_client_id(m, &id));
         verify_client_id(m, &id);
 
+        /* parameter request list */
+        ASSERT_OK(dhcp_message_append_option_parameter_request_list(m, prl));
+        ASSERT_OK(dhcp_message_append_option_parameter_request_list(m, prl));
+        verify_prl(m, prl);
+
         /* build and parse */
         _cleanup_(iovw_done_free) struct iovec_wrapper iovw = {};
         ASSERT_OK(dhcp_message_build(m, &iovw));
@@ -235,6 +251,7 @@ TEST(dhcp_message) {
         verify_addresses(m2, ELEMENTSOF(ntp), ntp);
         verify_string(m2, vendor_class);
         verify_client_id(m2, &id);
+        verify_prl(m2, prl);
 
         /* build again, and verify the packet */
         _cleanup_(iovw_done_free) struct iovec_wrapper iovw2 = {};