From 700f5abbeff4e3dcc0f6b12d4883315e2cfb9b74 Mon Sep 17 00:00:00 2001 From: Hans Dedecker Date: Wed, 28 Dec 2016 10:57:30 +0100 Subject: [PATCH] dhcpv4: fix DHCPv4 hostname handling Fix hostname not being reported as "-" in the DHCP statefile in case no hostname is reported by the DHCPv4 client (https://:wqgithub.com/openwrt/odhcpd/issues/94) Signed-off-by: Hans Dedecker --- src/dhcpv4.c | 90 ++++++++++++++++++++++++------------------------- src/dhcpv4.h | 3 +- src/dhcpv6-ia.c | 3 +- 3 files changed, 49 insertions(+), 47 deletions(-) diff --git a/src/dhcpv4.c b/src/dhcpv4.c index 509b092..9d9ed92 100644 --- a/src/dhcpv4.c +++ b/src/dhcpv4.c @@ -1,5 +1,6 @@ /** * Copyright (C) 2012-2013 Steven Barth + * Copyright (C) 2016 Hans Dedecker * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License v2 as published by @@ -32,12 +33,12 @@ #include "dhcpv4.h" #include "dhcpv6.h" - +static void free_dhcpv4_assignment(struct dhcpv4_assignment *a); static void handle_dhcpv4(void *addr, void *data, size_t len, struct interface *iface, void *dest_addr); static struct dhcpv4_assignment* dhcpv4_lease(struct interface *iface, enum dhcpv4_msg msg, const uint8_t *mac, struct in_addr reqaddr, - uint32_t *leasetime, const char *hostname); + uint32_t *leasetime, const char *hostname, const size_t hostname_len); // Create socket and register events int init_dhcpv4(void) @@ -169,8 +170,7 @@ int setup_dhcpv4_interface(struct interface *iface, bool enable) struct lease *lease; list_for_each_entry(lease, &leases, head) { // Construct entry - size_t hostlen = strlen(lease->hostname) + 1; - struct dhcpv4_assignment *a = calloc(1, sizeof(*a) + hostlen); + struct dhcpv4_assignment *a = calloc(1, sizeof(*a)); if (!a) { syslog(LOG_ERR, "Calloc failed for static lease on interface %s", iface->ifname); @@ -178,9 +178,9 @@ int setup_dhcpv4_interface(struct interface *iface, bool enable) } if (lease->dhcpv4_leasetime >= 60) a->leasetime = lease->dhcpv4_leasetime; + a->addr = ntohl(lease->ipaddr.s_addr); memcpy(a->hwaddr, lease->mac.ether_addr_octet, sizeof(a->hwaddr)); - memcpy(a->hostname, lease->hostname, hostlen); /* Static assignment */ a->flags |= OAF_STATIC; /* Infinite valid */ @@ -201,18 +201,21 @@ int setup_dhcpv4_interface(struct interface *iface, bool enable) list_add(&a->head, &iface->dhcpv4_assignments); } - if (!a->head.next) - free(a); + if (a->head.next) { + if (lease->hostname[0]) { + free(a->hostname); + a->hostname = strdup(lease->hostname); + } + } else + free_dhcpv4_assignment(a); } // Clean invalid assignments struct dhcpv4_assignment *a, *n; list_for_each_entry_safe(a, n, &iface->dhcpv4_assignments, head) { if ((htonl(a->addr) & smask->sin_addr.s_addr) != - (iface->dhcpv4_start.s_addr & smask->sin_addr.s_addr)) { - list_del(&a->head); - free(a); - } + (iface->dhcpv4_start.s_addr & smask->sin_addr.s_addr)) + free_dhcpv4_assignment(a); } @@ -223,17 +226,21 @@ int setup_dhcpv4_interface(struct interface *iface, bool enable) iface->dhcpv4_event.handle_dgram = handle_dhcpv4; odhcpd_register(&iface->dhcpv4_event); } else if (iface->dhcpv4_assignments.next) { - while (!list_empty(&iface->dhcpv4_assignments)) { - struct dhcpv4_assignment *a = list_first_entry(&iface->dhcpv4_assignments, - struct dhcpv4_assignment, head); - list_del(&a->head); - free(a); - } - + while (!list_empty(&iface->dhcpv4_assignments)) + free_dhcpv4_assignment(list_first_entry(&iface->dhcpv4_assignments, + struct dhcpv4_assignment, head)); } return 0; } +static void free_dhcpv4_assignment(struct dhcpv4_assignment *a) +{ + if (a->head.next) + list_del(&a->head); + + free(a->hostname); + free(a); +} static void dhcpv4_put(struct dhcpv4_message *msg, uint8_t **cookie, uint8_t type, uint8_t len, const void *data) @@ -315,8 +322,8 @@ static void handle_dhcpv4(void *addr, void *data, size_t len, struct in_addr reqaddr = {INADDR_ANY}; uint32_t leasetime = 0; + size_t hostname_len = 0; char hostname[256]; - hostname[0] = 0; uint8_t *start = &req->options[4]; uint8_t *end = ((uint8_t*)data) + len; @@ -325,8 +332,9 @@ static void handle_dhcpv4(void *addr, void *data, size_t len, if (opt->type == DHCPV4_OPT_MESSAGE && opt->len == 1) { reqmsg = opt->data[0]; } else if (opt->type == DHCPV4_OPT_HOSTNAME && opt->len > 0) { - memcpy(hostname, opt->data, opt->len); - hostname[opt->len] = 0; + hostname_len = opt->len; + memcpy(hostname, opt->data, hostname_len); + hostname[hostname_len] = 0; } else if (opt->type == DHCPV4_OPT_IPADDRESS && opt->len == 4) { memcpy(&reqaddr, opt->data, 4); } else if (opt->type == DHCPV4_OPT_SERVERID && opt->len == 4) { @@ -350,7 +358,8 @@ static void handle_dhcpv4(void *addr, void *data, size_t len, struct dhcpv4_assignment *lease = NULL; if (reqmsg != DHCPV4_MSG_INFORM) - lease = dhcpv4_lease(iface, reqmsg, req->chaddr, reqaddr, &leasetime, hostname); + lease = dhcpv4_lease(iface, reqmsg, req->chaddr, reqaddr, + &leasetime, hostname, hostname_len); if (!lease) { if (reqmsg == DHCPV4_MSG_REQUEST) @@ -403,7 +412,7 @@ static void handle_dhcpv4(void *addr, void *data, size_t len, dhcpv4_put(&reply, &cookie, DHCPV4_OPT_NETMASK, 4, &ifnetmask.sin_addr); - if (lease->hostname[0]) + if (lease->hostname) dhcpv4_put(&reply, &cookie, DHCPV4_OPT_HOSTNAME, strlen(lease->hostname), lease->hostname); @@ -585,7 +594,7 @@ static bool dhcpv4_assign(struct interface *iface, static struct dhcpv4_assignment* dhcpv4_lease(struct interface *iface, enum dhcpv4_msg msg, const uint8_t *mac, struct in_addr reqaddr, - uint32_t *leasetime, const char *hostname) + uint32_t *leasetime, const char *hostname, const size_t hostname_len) { struct dhcpv4_assignment *lease = NULL; uint32_t raddr = ntohl(reqaddr.s_addr); @@ -597,44 +606,27 @@ static struct dhcpv4_assignment* dhcpv4_lease(struct interface *iface, a = c; if (c->addr == raddr) break; - } else if (!INFINITE_VALID(c->valid_until) && c->valid_until < now) { - list_del(&c->head); - free(c); - } + } else if (!INFINITE_VALID(c->valid_until) && c->valid_until < now) + free_dhcpv4_assignment(c); } if (msg == DHCPV4_MSG_DISCOVER || msg == DHCPV4_MSG_REQUEST) { bool assigned = !!a; - size_t hostlen = strlen(hostname) + 1; uint32_t my_leasetime; if (!a && !iface->no_dynamic_dhcp) { // Create new binding - a = calloc(1, sizeof(*a) + hostlen); + a = calloc(1, sizeof(*a)); if (!a) { syslog(LOG_ERR, "Failed to calloc binding on interface %s", iface->ifname); return NULL; } memcpy(a->hwaddr, mac, sizeof(a->hwaddr)); - memcpy(a->hostname, hostname, hostlen); // Don't consider new assignment as infinite a->valid_until = now; assigned = dhcpv4_assign(iface, a, raddr); } - if (assigned && !a->hostname[0] && hostname) { - a = realloc(a, sizeof(*a) + hostlen); - if (!a) { - syslog(LOG_ERR, "Failed to realloc binding on interface %s", iface->ifname); - return NULL; - } - memcpy(a->hostname, hostname, hostlen); - - // Fixup list - a->head.next->prev = &a->head; - a->head.prev->next = &a->head; - } - if (a->leasetime >= 60) { my_leasetime = a->leasetime; } else { @@ -651,13 +643,21 @@ static struct dhcpv4_assignment* dhcpv4_lease(struct interface *iface, if (!(a->flags & OAF_STATIC)) a->valid_until = now; } else { + if (hostname_len > 0) { + a->hostname = realloc(a->hostname, hostname_len + 1); + if (a->hostname) { + memcpy(a->hostname, hostname, hostname_len); + a->hostname[hostname_len] = 0; + } + } + a->flags |= OAF_BOUND; if (!(a->flags & OAF_STATIC)) a->valid_until = ((*leasetime == UINT32_MAX) ? 0 : (time_t)(now + *leasetime)); } } else if (!assigned && a) { // Cleanup failed assignment - free(a); + free_dhcpv4_assignment(a); a = NULL; } diff --git a/src/dhcpv4.h b/src/dhcpv4.h index cd6c978..4d14f09 100644 --- a/src/dhcpv4.h +++ b/src/dhcpv4.h @@ -1,5 +1,6 @@ /** * Copyright (C) 2012 Steven Barth + * Copyright (C) 2016 Hans Dedecker * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 @@ -80,7 +81,7 @@ struct dhcpv4_assignment { uint8_t hwaddr[6]; uint32_t leasetime; unsigned int flags; - char hostname[]; + char *hostname; }; struct dhcpv4_option { diff --git a/src/dhcpv6-ia.c b/src/dhcpv6-ia.c index a7146a7..b0a0ada 100644 --- a/src/dhcpv6-ia.c +++ b/src/dhcpv6-ia.c @@ -1,5 +1,6 @@ /** * Copyright (C) 2013 Steven Barth + * Copyright (C) 2016 Hans Dedecker * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License v2 as published by @@ -324,7 +325,7 @@ void dhcpv6_write_statefile(void) struct in_addr addr = {htonl(c->addr)}; inet_ntop(AF_INET, &addr, ipbuf, sizeof(ipbuf) - 1); - if (c->hostname[0]) { + if (c->hostname) { fputs(ipbuf, fp); char b[256]; -- 2.30.2