From f9edbb80e9df8b471de0a9620bdde0e5414d4aee Mon Sep 17 00:00:00 2001 From: Yu Watanabe Date: Thu, 21 Sep 2023 04:39:49 +0900 Subject: [PATCH] sd-dhcp-client: split out client_parse_message() No functional change, just refactoring and preparation for later commits. --- src/libsystemd-network/fuzz-dhcp-client.c | 1 + src/libsystemd-network/sd-dhcp-client.c | 120 +++++++++++++--------- 2 files changed, 70 insertions(+), 51 deletions(-) diff --git a/src/libsystemd-network/fuzz-dhcp-client.c b/src/libsystemd-network/fuzz-dhcp-client.c index d2bbf660b0d..9b9e741e534 100644 --- a/src/libsystemd-network/fuzz-dhcp-client.c +++ b/src/libsystemd-network/fuzz-dhcp-client.c @@ -73,6 +73,7 @@ int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) { res = sd_dhcp_client_start(client); assert_se(IN_SET(res, 0, -EINPROGRESS)); client->xid = 2; + client->state = DHCP_STATE_SELECTING; (void) client_handle_offer(client, (DHCPMessage*) data, size); diff --git a/src/libsystemd-network/sd-dhcp-client.c b/src/libsystemd-network/sd-dhcp-client.c index e3f637736ec..cfdee5d6b4e 100644 --- a/src/libsystemd-network/sd-dhcp-client.c +++ b/src/libsystemd-network/sd-dhcp-client.c @@ -1546,10 +1546,20 @@ static int client_timeout_t1(sd_event_source *s, uint64_t usec, void *userdata) return client_initialize_time_events(client); } -static int client_handle_offer(sd_dhcp_client *client, DHCPMessage *offer, size_t len) { +static int client_parse_message( + sd_dhcp_client *client, + DHCPMessage *message, + size_t len, + sd_dhcp_lease **ret) { + _cleanup_(sd_dhcp_lease_unrefp) sd_dhcp_lease *lease = NULL; + _cleanup_free_ char *error_message = NULL; int r; + assert(client); + assert(message); + assert(ret); + r = dhcp_lease_new(&lease); if (r < 0) return r; @@ -1562,28 +1572,66 @@ static int client_handle_offer(sd_dhcp_client *client, DHCPMessage *offer, size_ return r; } - r = dhcp_option_parse(offer, len, dhcp_lease_parse_options, lease, NULL); - if (r != DHCP_OFFER) - return log_dhcp_client_errno(client, SYNTHETIC_ERRNO(ENOMSG), - "received message was not an OFFER, ignoring"); + r = dhcp_option_parse(message, len, dhcp_lease_parse_options, lease, &error_message); + if (r < 0) + return log_dhcp_client_errno(client, r, "Failed to parse DHCP options, ignoring: %m"); - lease->next_server = offer->siaddr; - lease->address = offer->yiaddr; + switch (client->state) { + case DHCP_STATE_SELECTING: + if (r != DHCP_OFFER) + return log_dhcp_client_errno(client, SYNTHETIC_ERRNO(ENOMSG), + "received message was not an OFFER, ignoring."); - if (lease->lifetime == 0 && client->fallback_lease_lifetime > 0) - lease->lifetime = client->fallback_lease_lifetime; + if (lease->lifetime == 0 && client->fallback_lease_lifetime > 0) + lease->lifetime = client->fallback_lease_lifetime; + + break; + + case DHCP_STATE_REBOOTING: + case DHCP_STATE_REQUESTING: + case DHCP_STATE_RENEWING: + case DHCP_STATE_REBINDING: + if (r == DHCP_NAK) + return log_dhcp_client_errno(client, SYNTHETIC_ERRNO(EADDRNOTAVAIL), + "NAK: %s", strna(error_message)); + if (r != DHCP_ACK) + return log_dhcp_client_errno(client, SYNTHETIC_ERRNO(ENOMSG), + "received message was not an ACK, ignoring."); + break; + + default: + assert_not_reached(); + } + + lease->next_server = message->siaddr; + lease->address = message->yiaddr; if (lease->address == 0 || lease->server_address == 0 || lease->lifetime == 0) return log_dhcp_client_errno(client, SYNTHETIC_ERRNO(ENOMSG), - "received lease lacks address, server address or lease lifetime, ignoring"); + "received lease lacks address, server address or lease lifetime, ignoring."); r = dhcp_lease_set_default_subnet_mask(lease); if (r < 0) return log_dhcp_client_errno(client, SYNTHETIC_ERRNO(ENOMSG), "received lease lacks subnet mask, and a fallback one cannot be generated, ignoring."); + *ret = TAKE_PTR(lease); + return 0; +} + +static int client_handle_offer(sd_dhcp_client *client, DHCPMessage *message, size_t len) { + _cleanup_(sd_dhcp_lease_unrefp) sd_dhcp_lease *lease = NULL; + int r; + + assert(client); + assert(message); + + r = client_parse_message(client, message, len, &lease); + if (r < 0) + return r; + dhcp_lease_unref_and_replace(client->lease, lease); if (client_notify(client, SD_DHCP_CLIENT_EVENT_SELECTING) < 0) @@ -1643,46 +1691,16 @@ static bool lease_equal(const sd_dhcp_lease *a, const sd_dhcp_lease *b) { return true; } -static int client_handle_ack(sd_dhcp_client *client, DHCPMessage *ack, size_t len) { +static int client_handle_ack(sd_dhcp_client *client, DHCPMessage *message, size_t len) { _cleanup_(sd_dhcp_lease_unrefp) sd_dhcp_lease *lease = NULL; - _cleanup_free_ char *error_message = NULL; int r; - r = dhcp_lease_new(&lease); - if (r < 0) - return r; - - if (client->client_id_len > 0) { - r = dhcp_lease_set_client_id(lease, - (uint8_t *) &client->client_id, - client->client_id_len); - if (r < 0) - return r; - } - - r = dhcp_option_parse(ack, len, dhcp_lease_parse_options, lease, &error_message); - if (r == DHCP_NAK) - return log_dhcp_client_errno(client, SYNTHETIC_ERRNO(EADDRNOTAVAIL), - "NAK: %s", strna(error_message)); - - if (r != DHCP_ACK) - return log_dhcp_client_errno(client, SYNTHETIC_ERRNO(ENOMSG), - "received message was not an ACK, ignoring"); - - lease->next_server = ack->siaddr; - - lease->address = ack->yiaddr; - - if (lease->address == INADDR_ANY || - lease->server_address == INADDR_ANY || - lease->lifetime == 0) - return log_dhcp_client_errno(client, SYNTHETIC_ERRNO(ENOMSG), - "received lease lacks address, server address or lease lifetime, ignoring"); + assert(client); + assert(message); - r = dhcp_lease_set_default_subnet_mask(lease); + r = client_parse_message(client, message, len, &lease); if (r < 0) - return log_dhcp_client_errno(client, SYNTHETIC_ERRNO(ENOMSG), - "received lease lacks subnet mask, and a fallback one cannot be generated, ignoring."); + return r; if (!client->lease) r = SD_DHCP_CLIENT_EVENT_IP_ACQUIRE; @@ -1851,10 +1869,10 @@ static int client_handle_message(sd_dhcp_client *client, DHCPMessage *message, i case DHCP_STATE_SELECTING: r = client_handle_offer(client, message, len); - if (r == -ENOMSG) - return 0; /* invalid message, let's ignore it */ - if (r < 0) + if (ERRNO_IS_NEG_RESOURCE(r)) goto error; + if (r < 0) + return 0; /* invalid message, let's ignore it */ r = client_enter_requesting(client); break; @@ -1865,8 +1883,8 @@ static int client_handle_message(sd_dhcp_client *client, DHCPMessage *message, i case DHCP_STATE_REBINDING: r = client_handle_ack(client, message, len); - if (r == -ENOMSG) - return 0; /* invalid message, let's ignore it */ + if (ERRNO_IS_NEG_RESOURCE(r)) + goto error; if (r == -EADDRNOTAVAIL) { /* got a NAK, let's restart the client */ client_notify(client, SD_DHCP_CLIENT_EVENT_EXPIRED); @@ -1886,7 +1904,7 @@ static int client_handle_message(sd_dhcp_client *client, DHCPMessage *message, i return 0; } if (r < 0) - goto error; + return 0; /* invalid message, let's ignore it */ r = client_enter_bound(client, r); break; -- 2.47.3