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import of dnsmasq-2.19.tar.gz

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This commit is contained in:
Simon Kelley
2004-12-13 20:56:23 +00:00
parent 59353a6b56
commit bb01cb9604
9 changed files with 118 additions and 63 deletions
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18
CHANGELOG
View File

@@ -1307,8 +1307,22 @@ version 2.18
Enable long command line options on FreeBSD when the Enable long command line options on FreeBSD when the
C library supports them. C library supports them.
version 2.19
Tweaked the Linux-only interface discovery code to cope
with interface-indexes larger than 8 bits in
/proc/net/if_inet6. This only affects Linux, obviously.
Thanks to Richard Atterer for the bug report.
Check for under-length option fields in DHCP packets, a
zero length client-id, in particluar, could seriously
confuse dnsmasq 'till now. Thanks to Will Murname for help
with that.
If a DHCP-allocated address has an associated name in
/etc/hosts, and the client does not provide a hostname
parameter and there is no hostname in a matching dhcp-host
option, send the /etc/hosts name as the hostname in
the DHCP lease. Thanks to Will Murname for the suggestion.

19
FAQ
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@@ -115,7 +115,7 @@ A: Resolver code sometime does strange things when given names without
--expand-hosts and --domain-suffix options. --expand-hosts and --domain-suffix options.
Q: Can I get dnsmasq to save the contents of its cache to disk when Q: Can I get dnsmasq to save the contents of its cache to disk when
I shut my machine down and re-load when it starts again. I shut my machine down and re-load when it starts again?
A: No, that facility is not provided. Very few names in the DNS have A: No, that facility is not provided. Very few names in the DNS have
their time-to-live set for longer than a few hours so most of the their time-to-live set for longer than a few hours so most of the
@@ -299,7 +299,22 @@ A: Because when a Gentoo box shuts down, it releases its lease with
dnsmasq ignores it until is times out and restarts the process. dnsmasq ignores it until is times out and restarts the process.
To fix this, set the dhcp-authoritative flag in dnsmasq. To fix this, set the dhcp-authoritative flag in dnsmasq.
Q: My laptop has two network interfaces, a wired one and a wireless
one. I never use both interfaces at the same time, and I'd like the
same IP and configuration to be used irrespcetive of which
interface is in use. How can I do that.
A: By default, the identity of a machine is determined by using the
MAC address, which is associated with interface hardware. Once an
IP is bound to the MAC address of one interface, it cannot be
associated with another MAC address until after the DHCP lease
expires. The solution to this is to use a client-id as the machine
identity rather than the MAC address. If you arrange for the same
client-id to sent when either interface is in use, the DHCP server
will recognise the same machine, and use the same address. The
method for setting the client-id varies with DHCP client software,
dhcpcd uses the "-I" flag. Windows uses a registry setting,
see http://www.jsiinc.com/SUBF/TIP2800/rh2845.htm

2
dnsmasq-rh.spec
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@@ -5,7 +5,7 @@
############################################################################### ###############################################################################
Name: dnsmasq Name: dnsmasq
Version: 2.18 Version: 2.19
Release: 1 Release: 1
Copyright: GPL Copyright: GPL
Group: System Environment/Daemons Group: System Environment/Daemons

2
dnsmasq-suse.spec
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@@ -5,7 +5,7 @@
############################################################################### ###############################################################################
Name: dnsmasq Name: dnsmasq
Version: 2.18 Version: 2.19
Release: 1 Release: 1
Copyright: GPL Copyright: GPL
Group: Productivity/Networking/DNS/Servers Group: Productivity/Networking/DNS/Servers

2
src/config.h
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@@ -12,7 +12,7 @@
/* Author's email: simon@thekelleys.org.uk */ /* Author's email: simon@thekelleys.org.uk */
#define VERSION "2.18" #define VERSION "2.19"
#define FTABSIZ 150 /* max number of outstanding requests */ #define FTABSIZ 150 /* max number of outstanding requests */
#define MAX_PROCS 20 /* max no children for TCP requests */ #define MAX_PROCS 20 /* max no children for TCP requests */

38
src/dhcp.c
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@@ -656,3 +656,41 @@ void dhcp_update_configs(struct dhcp_config *configs)
} }
} }
/* If we've not found a hostname any other way, try and see if there's one in /etc/hosts
for this address. If it has a domain part, that must match the set domain and
it gets stripped. */
char *host_from_dns(struct daemon *daemon, struct in_addr addr)
{
struct crec *lookup = cache_find_by_addr(NULL, (struct all_addr *)&addr, 0, F_IPV4);
char *hostname = NULL;
if (lookup && (lookup->flags & F_HOSTS))
{
hostname = daemon->dhcp_buff;
hostname[256] = 0;
strncpy(hostname, cache_get_name(lookup), 256);
hostname = strip_hostname(daemon, hostname);
}
return hostname;
}
char *strip_hostname(struct daemon *daemon, char *hostname)
{
char *dot = strchr(hostname, '.');
if (dot)
{
if (!daemon->domain_suffix || !hostname_isequal(dot+1, daemon->domain_suffix))
{
syslog(LOG_WARNING, "Ignoring DHCP host name %s because it has an illegal domain part", hostname);
hostname = NULL;
}
else
{
*dot = 0; /* truncate */
if (strlen(hostname) == 0)
hostname = NULL; /* nothing left */
}
}
return hostname;
}

2
src/dnsmasq.h
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@@ -478,6 +478,8 @@ struct dhcp_config *find_config(struct dhcp_config *configs,
void dhcp_update_configs(struct dhcp_config *configs); void dhcp_update_configs(struct dhcp_config *configs);
void dhcp_read_ethers(struct daemon *daemon); void dhcp_read_ethers(struct daemon *daemon);
struct dhcp_config *config_find_by_address(struct dhcp_config *configs, struct in_addr addr); struct dhcp_config *config_find_by_address(struct dhcp_config *configs, struct in_addr addr);
char *strip_hostname(struct daemon *daemon, char *hostname);
char *host_from_dns(struct daemon *daemon, struct in_addr addr);
/* lease.c */ /* lease.c */
void lease_update_file(int force, time_t now); void lease_update_file(int force, time_t now);

4
src/network.c
View File

@@ -178,7 +178,7 @@ struct irec *enumerate_interfaces(struct daemon *daemon)
unsigned int plen, scope, flags, if_idx; unsigned int plen, scope, flags, if_idx;
char devname[20], addrstring[32]; char devname[20], addrstring[32];
while (fscanf(f, "%32s %02x %02x %02x %02x %20s\n", while (fscanf(f, "%32s %x %x %x %x %20s\n",
addrstring, &if_idx, &plen, &scope, &flags, devname) != EOF) addrstring, &if_idx, &plen, &scope, &flags, devname) != EOF)
{ {
int i; int i;
@@ -199,9 +199,7 @@ struct irec *enumerate_interfaces(struct daemon *daemon)
strncpy(sifr.ifr_name, devname, IF_NAMESIZE); strncpy(sifr.ifr_name, devname, IF_NAMESIZE);
if (ioctl(fd, SIOCGIFFLAGS, &sifr) < 0) if (ioctl(fd, SIOCGIFFLAGS, &sifr) < 0)
die("ioctl error getting interface flags: %m", NULL); die("ioctl error getting interface flags: %m", NULL);
iface = add_iface(daemon, iface, sifr.ifr_name, sifr.ifr_flags & IFF_LOOPBACK, &addr); iface = add_iface(daemon, iface, sifr.ifr_name, sifr.ifr_flags & IFF_LOOPBACK, &addr);
} }
fclose(f); fclose(f);
} }

98
src/rfc2131.c
View File

@@ -59,13 +59,13 @@ static unsigned char *option_end(unsigned char *p, unsigned char *end, struct dh
static unsigned char *option_put_string(unsigned char *p, unsigned char *end, int opt, char *string); static unsigned char *option_put_string(unsigned char *p, unsigned char *end, int opt, char *string);
static void bootp_option_put(struct dhcp_packet *mess, static void bootp_option_put(struct dhcp_packet *mess,
struct dhcp_boot *boot_opts, struct dhcp_netid *netids); struct dhcp_boot *boot_opts, struct dhcp_netid *netids);
static int option_len(unsigned char *opt); static unsigned int option_len(unsigned char *opt);
static void *option_ptr(unsigned char *opt); static void *option_ptr(unsigned char *opt);
static struct in_addr option_addr(unsigned char *opt); static struct in_addr option_addr(unsigned char *opt);
static unsigned int option_uint(unsigned char *opt, int size); static unsigned int option_uint(unsigned char *opt, int size);
static void log_packet(char *type, struct in_addr *addr, unsigned char *hwaddr, char *interface, char *string); static void log_packet(char *type, struct in_addr *addr, unsigned char *hwaddr, char *interface, char *string);
static int match_netid(struct dhcp_netid *check, struct dhcp_netid *pool); static int match_netid(struct dhcp_netid *check, struct dhcp_netid *pool);
static unsigned char *option_find(struct dhcp_packet *mess, int size, int opt_type); static unsigned char *option_find(struct dhcp_packet *mess, int size, int opt_type, unsigned int minsize);
static unsigned char *do_req_options(struct dhcp_context *context, static unsigned char *do_req_options(struct dhcp_context *context,
unsigned char *p, unsigned char *end, unsigned char *p, unsigned char *end,
unsigned char *req_options, unsigned char *req_options,
@@ -126,7 +126,7 @@ int dhcp_reply(struct daemon *daemon, struct in_addr iface_addr, char *iface_nam
return 0; return 0;
/* check for DHCP rather than BOOTP */ /* check for DHCP rather than BOOTP */
if ((opt = option_find(mess, sz, OPTION_MESSAGE_TYPE))) if ((opt = option_find(mess, sz, OPTION_MESSAGE_TYPE, 1)))
{ {
mess_type = option_uint(opt, 1); mess_type = option_uint(opt, 1);
@@ -136,18 +136,18 @@ int dhcp_reply(struct daemon *daemon, struct in_addr iface_addr, char *iface_nam
/* Some buggy clients set ciaddr when they shouldn't, so clear that here since /* Some buggy clients set ciaddr when they shouldn't, so clear that here since
it can affect the context-determination code. */ it can affect the context-determination code. */
if ((option_find(mess, sz, OPTION_REQUESTED_IP) || mess_type == DHCPDISCOVER)) if ((option_find(mess, sz, OPTION_REQUESTED_IP, INADDRSZ) || mess_type == DHCPDISCOVER))
mess->ciaddr.s_addr = 0; mess->ciaddr.s_addr = 0;
/* Check for RFC3011 subnet selector */ /* Check for RFC3011 subnet selector */
if ((opt = option_find(mess, sz, OPTION_SUBNET_SELECT))) if ((opt = option_find(mess, sz, OPTION_SUBNET_SELECT, INADDRSZ)))
subnet_addr = option_addr(opt); subnet_addr = option_addr(opt);
/* If there is no client identifier option, use the hardware address */ /* If there is no client identifier option, use the hardware address */
if ((opt = option_find(mess, sz, OPTION_CLIENT_ID))) if ((opt = option_find(mess, sz, OPTION_CLIENT_ID, 1)))
{ {
clid = option_ptr(opt);
clid_len = option_len(opt); clid_len = option_len(opt);
clid = option_ptr(opt);
} }
else else
clid = mess->chaddr; clid = mess->chaddr;
@@ -253,9 +253,9 @@ int dhcp_reply(struct daemon *daemon, struct in_addr iface_addr, char *iface_nam
if (have_config(config, CONFIG_NAME)) if (have_config(config, CONFIG_NAME))
hostname = config->hostname; hostname = config->hostname;
else if ((opt = option_find(mess, sz, OPTION_HOSTNAME))) else if ((opt = option_find(mess, sz, OPTION_HOSTNAME, 1)))
{ {
int len = option_len(opt); unsigned int len = option_len(opt);
hostname = daemon->dhcp_buff; hostname = daemon->dhcp_buff;
memcpy(hostname, option_ptr(opt), len); memcpy(hostname, option_ptr(opt), len);
/* May not be zero terminated */ /* May not be zero terminated */
@@ -263,33 +263,14 @@ int dhcp_reply(struct daemon *daemon, struct in_addr iface_addr, char *iface_nam
/* ensure there are no strange chars in there */ /* ensure there are no strange chars in there */
if (!canonicalise(hostname)) if (!canonicalise(hostname))
hostname = NULL; hostname = NULL;
else else if ((hostname = strip_hostname(daemon, hostname)) && !config)
{ {
char *dot = strchr(hostname, '.');
if (dot)
{
if (!daemon->domain_suffix || !hostname_isequal(dot+1, daemon->domain_suffix))
{
syslog(LOG_WARNING, "Ignoring DHCP host name %s because it has an illegal domain part", hostname);
hostname = NULL;
}
else
{
*dot = 0; /* truncate */
if (strlen(hostname) == 0)
hostname = NULL; /* nothing left */
}
}
/* Search again now we have a hostname. /* Search again now we have a hostname.
Only accept configs without CLID and HWADDR here, (they won't match) Only accept configs without CLID and HWADDR here, (they won't match)
to avoid impersonation by name. */ to avoid impersonation by name. */
if (!config) struct dhcp_config *new = find_config(daemon->dhcp_conf, context, NULL, 0, mess->chaddr, hostname);
{ if (!have_config(new, CONFIG_CLID) && !have_config(new, CONFIG_HWADDR))
struct dhcp_config *new = find_config(daemon->dhcp_conf, context, NULL, 0, mess->chaddr, hostname); config = new;
if (!have_config(new, CONFIG_CLID) && !have_config(new, CONFIG_HWADDR))
config = new;
}
} }
} }
@@ -307,10 +288,10 @@ int dhcp_reply(struct daemon *daemon, struct in_addr iface_addr, char *iface_nam
assume that the option is a single string and non RFC3004 compliant assume that the option is a single string and non RFC3004 compliant
and just do the substring match. dhclient provides these broken options. */ and just do the substring match. dhclient provides these broken options. */
if ((opt = option_find(mess, sz, OPTION_USER_CLASS))) if ((opt = option_find(mess, sz, OPTION_USER_CLASS, 1)))
{ {
unsigned char *ucp = option_ptr(opt); unsigned char *ucp = option_ptr(opt);
int tmp, j; unsigned int tmp, j;
for (j = 0; j < option_len(opt); j += ucp[j] + 1); for (j = 0; j < option_len(opt); j += ucp[j] + 1);
if (j == option_len(opt)) if (j == option_len(opt))
for (j = 0; j < option_len(opt); j = tmp) for (j = 0; j < option_len(opt); j = tmp)
@@ -321,9 +302,9 @@ int dhcp_reply(struct daemon *daemon, struct in_addr iface_addr, char *iface_nam
} }
for (vendor = daemon->dhcp_vendors; vendor; vendor = vendor->next) for (vendor = daemon->dhcp_vendors; vendor; vendor = vendor->next)
if ((opt = option_find(mess, sz, vendor->is_vendor ? OPTION_VENDOR_ID : OPTION_USER_CLASS))) if ((opt = option_find(mess, sz, vendor->is_vendor ? OPTION_VENDOR_ID : OPTION_USER_CLASS, 1)))
{ {
int i; unsigned int i;
for (i = 0; i <= (option_len(opt) - vendor->len); i++) for (i = 0; i <= (option_len(opt) - vendor->len); i++)
if (memcmp(vendor->data, option_ptr(opt)+i, vendor->len) == 0) if (memcmp(vendor->data, option_ptr(opt)+i, vendor->len) == 0)
{ {
@@ -348,23 +329,22 @@ int dhcp_reply(struct daemon *daemon, struct in_addr iface_addr, char *iface_nam
/* do we have a lease in store? */ /* do we have a lease in store? */
lease = lease_find_by_client(clid, clid_len); lease = lease_find_by_client(clid, clid_len);
if ((opt = option_find(mess, sz, OPTION_REQUESTED_OPTIONS))) if ((opt = option_find(mess, sz, OPTION_REQUESTED_OPTIONS, 0)))
{ {
int len = option_len(opt);
req_options = daemon->dhcp_buff2; req_options = daemon->dhcp_buff2;
memcpy(req_options, option_ptr(opt), len); memcpy(req_options, option_ptr(opt), option_len(opt));
req_options[len] = OPTION_END; req_options[option_len(opt)] = OPTION_END;
} }
switch (mess_type) switch (mess_type)
{ {
case DHCPDECLINE: case DHCPDECLINE:
if (!(opt = option_find(mess, sz, OPTION_SERVER_IDENTIFIER)) || if (!(opt = option_find(mess, sz, OPTION_SERVER_IDENTIFIER, INADDRSZ)) ||
(iface_addr.s_addr != option_addr(opt).s_addr)) (iface_addr.s_addr != option_addr(opt).s_addr))
return 0; return 0;
/* sanitise any message. Paranoid? Moi? */ /* sanitise any message. Paranoid? Moi? */
if ((opt = option_find(mess, sz, OPTION_MESSAGE))) if ((opt = option_find(mess, sz, OPTION_MESSAGE, 1)))
{ {
char *p = option_ptr(opt), *q = daemon->dhcp_buff; char *p = option_ptr(opt), *q = daemon->dhcp_buff;
int i; int i;
@@ -379,7 +359,7 @@ int dhcp_reply(struct daemon *daemon, struct in_addr iface_addr, char *iface_nam
message = daemon->dhcp_buff; message = daemon->dhcp_buff;
} }
if (!(opt = option_find(mess, sz, OPTION_REQUESTED_IP))) if (!(opt = option_find(mess, sz, OPTION_REQUESTED_IP, INADDRSZ)))
return 0; return 0;
log_packet("DECLINE", option_ptr(opt), mess->chaddr, iface_name, message); log_packet("DECLINE", option_ptr(opt), mess->chaddr, iface_name, message);
@@ -401,7 +381,7 @@ int dhcp_reply(struct daemon *daemon, struct in_addr iface_addr, char *iface_nam
return 0; return 0;
case DHCPRELEASE: case DHCPRELEASE:
if (!(opt = option_find(mess, sz, OPTION_SERVER_IDENTIFIER)) || if (!(opt = option_find(mess, sz, OPTION_SERVER_IDENTIFIER, INADDRSZ)) ||
(iface_addr.s_addr != option_addr(opt).s_addr)) (iface_addr.s_addr != option_addr(opt).s_addr))
return 0; return 0;
@@ -415,7 +395,7 @@ int dhcp_reply(struct daemon *daemon, struct in_addr iface_addr, char *iface_nam
return 0; return 0;
case DHCPDISCOVER: case DHCPDISCOVER:
if ((opt = option_find(mess, sz, OPTION_REQUESTED_IP))) if ((opt = option_find(mess, sz, OPTION_REQUESTED_IP, INADDRSZ)))
addr = option_addr(opt); addr = option_addr(opt);
if (ignore || have_config(config, CONFIG_DISABLE)) if (ignore || have_config(config, CONFIG_DISABLE))
message = "ignored"; message = "ignored";
@@ -442,7 +422,7 @@ int dhcp_reply(struct daemon *daemon, struct in_addr iface_addr, char *iface_nam
} }
time = have_config(config, CONFIG_TIME) ? config->lease_time : context->lease_time; time = have_config(config, CONFIG_TIME) ? config->lease_time : context->lease_time;
if ((opt = option_find(mess, sz, OPTION_LEASE_TIME))) if ((opt = option_find(mess, sz, OPTION_LEASE_TIME, 4)))
{ {
unsigned int req_time = option_uint(opt, 4); unsigned int req_time = option_uint(opt, 4);
if (time == 0xffffffff || (req_time != 0xffffffff && req_time < time)) if (time == 0xffffffff || (req_time != 0xffffffff && req_time < time))
@@ -472,12 +452,12 @@ int dhcp_reply(struct daemon *daemon, struct in_addr iface_addr, char *iface_nam
case DHCPREQUEST: case DHCPREQUEST:
if (ignore || have_config(config, CONFIG_DISABLE)) if (ignore || have_config(config, CONFIG_DISABLE))
return 0; return 0;
if ((opt = option_find(mess, sz, OPTION_REQUESTED_IP))) if ((opt = option_find(mess, sz, OPTION_REQUESTED_IP, INADDRSZ)))
{ {
/* SELECTING or INIT_REBOOT */ /* SELECTING or INIT_REBOOT */
mess->yiaddr = option_addr(opt); mess->yiaddr = option_addr(opt);
if ((opt = option_find(mess, sz, OPTION_SERVER_IDENTIFIER))) if ((opt = option_find(mess, sz, OPTION_SERVER_IDENTIFIER, INADDRSZ)))
{ {
/* SELECTING */ /* SELECTING */
if (iface_addr.s_addr != option_addr(opt).s_addr) if (iface_addr.s_addr != option_addr(opt).s_addr)
@@ -569,7 +549,7 @@ int dhcp_reply(struct daemon *daemon, struct in_addr iface_addr, char *iface_nam
} }
time = have_config(config, CONFIG_TIME) ? config->lease_time : context->lease_time; time = have_config(config, CONFIG_TIME) ? config->lease_time : context->lease_time;
if ((opt = option_find(mess, sz, OPTION_LEASE_TIME))) if ((opt = option_find(mess, sz, OPTION_LEASE_TIME, 4)))
{ {
unsigned int req_time = option_uint(opt, 4); unsigned int req_time = option_uint(opt, 4);
if (time == 0xffffffff || (req_time != 0xffffffff && req_time < time)) if (time == 0xffffffff || (req_time != 0xffffffff && req_time < time))
@@ -577,6 +557,8 @@ int dhcp_reply(struct daemon *daemon, struct in_addr iface_addr, char *iface_nam
} }
lease_set_hwaddr(lease, mess->chaddr); lease_set_hwaddr(lease, mess->chaddr);
if (!hostname)
hostname = host_from_dns(daemon, mess->yiaddr);
if (hostname) if (hostname)
lease_set_hostname(lease, hostname, daemon->domain_suffix); lease_set_hostname(lease, hostname, daemon->domain_suffix);
lease_set_expires(lease, time == 0xffffffff ? 0 : now + (time_t)time); lease_set_expires(lease, time == 0xffffffff ? 0 : now + (time_t)time);
@@ -620,6 +602,8 @@ int dhcp_reply(struct daemon *daemon, struct in_addr iface_addr, char *iface_nam
bootp_option_put(mess, daemon->boot_config, netid); bootp_option_put(mess, daemon->boot_config, netid);
p = option_put(p, end, OPTION_MESSAGE_TYPE, 1, DHCPACK); p = option_put(p, end, OPTION_MESSAGE_TYPE, 1, DHCPACK);
p = option_put(p, end, OPTION_SERVER_IDENTIFIER, INADDRSZ, ntohl(iface_addr.s_addr)); p = option_put(p, end, OPTION_SERVER_IDENTIFIER, INADDRSZ, ntohl(iface_addr.s_addr));
if (!hostname)
hostname = host_from_dns(daemon, mess->yiaddr);
p = do_req_options(context, p, end, req_options, daemon, p = do_req_options(context, p, end, req_options, daemon,
hostname, iface_addr, netid, subnet_addr); hostname, iface_addr, netid, subnet_addr);
p = option_end(p, end, mess); p = option_end(p, end, mess);
@@ -644,7 +628,7 @@ static void log_packet(char *type, struct in_addr *addr, unsigned char *hwaddr,
string ? string : ""); string ? string : "");
} }
static int option_len(unsigned char *opt) static unsigned int option_len(unsigned char *opt)
{ {
return opt[1]; return opt[1];
} }
@@ -756,13 +740,13 @@ static unsigned char *option_find1(unsigned char *p, unsigned char *end, int opt
while (*p != OPTION_END) while (*p != OPTION_END)
{ {
if (end && (p >= end)) if (p >= end)
return 0; /* malformed packet */ return 0; /* malformed packet */
else if (*p == OPTION_PAD) else if (*p == OPTION_PAD)
p++; p++;
else if (*p == OPTION_OVERLOAD) else if (*p == OPTION_OVERLOAD)
{ {
if (end && (p >= end - 3)) if (p >= end - 3)
return 0; /* malformed packet */ return 0; /* malformed packet */
if (overload) if (overload)
*overload = *(p+2); *overload = *(p+2);
@@ -771,10 +755,10 @@ static unsigned char *option_find1(unsigned char *p, unsigned char *end, int opt
else else
{ {
int opt_len;; int opt_len;;
if (end && (p >= end - 2)) if (p >= end - 2)
return 0; /* malformed packet */ return 0; /* malformed packet */
opt_len = option_len(p); opt_len = option_len(p);
if (end && (p >= end - (2 + opt_len))) if (p >= end - (2 + opt_len))
return 0; /* malformed packet */ return 0; /* malformed packet */
if (*p == opt) if (*p == opt)
return p; return p;
@@ -785,7 +769,7 @@ static unsigned char *option_find1(unsigned char *p, unsigned char *end, int opt
return NULL; return NULL;
} }
static unsigned char *option_find(struct dhcp_packet *mess, int size, int opt_type) static unsigned char *option_find(struct dhcp_packet *mess, int size, int opt_type, unsigned int minsize)
{ {
int overload = 0; int overload = 0;
unsigned char *ret; unsigned char *ret;
@@ -799,6 +783,10 @@ static unsigned char *option_find(struct dhcp_packet *mess, int size, int opt_ty
if (!ret && (overload & 2)) if (!ret && (overload & 2))
ret = option_find1(&mess->sname[0], &mess->file[64], opt_type, &overload); ret = option_find1(&mess->sname[0], &mess->file[64], opt_type, &overload);
/* Check the option field is big enough */
if (ret && (option_len(ret) < minsize))
ret = NULL;
return ret; return ret;
} }