[PATCH 1/8 v4] net: dhcp: factorise option recption handling
Jean-Christophe PLAGNIOL-VILLARD
plagnioj at jcrosoft.com
Tue Apr 3 00:57:23 EDT 2012
Instead of using a static switch case the handle the received option
use an array of supported option.
This will allow to unset the env var without duplicating the code.
Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj at jcrosoft.com>
---
net/dhcp.c | 241 ++++++++++++++++++++++++++++++++++++++----------------------
1 files changed, 153 insertions(+), 88 deletions(-)
diff --git a/net/dhcp.c b/net/dhcp.c
index 53eed6c..750d879 100644
--- a/net/dhcp.c
+++ b/net/dhcp.c
@@ -76,6 +76,124 @@ static uint32_t dhcp_leasetime;
static IPaddr_t net_dhcp_server_ip;
static uint64_t dhcp_start;
+struct dhcp_opt {
+ unsigned char option;
+ /* request automatically the option when creating the DHCP request */
+ bool optional;
+ const char *barebox_var_name;
+ void (*handle)(struct dhcp_opt *opt, unsigned char *data, int tlen);
+ void *data;
+
+ struct bootp *bp;
+};
+
+static void netmask_handle(struct dhcp_opt *opt, unsigned char *popt, int optlen)
+{
+ IPaddr_t ip;
+
+ ip = net_read_ip(popt);
+ net_set_netmask(ip);
+}
+
+static void gateway_handle(struct dhcp_opt *opt, unsigned char *popt, int optlen)
+{
+ IPaddr_t ip;
+
+ ip = net_read_ip(popt);
+ net_set_gateway(ip);
+}
+
+static void env_ip_handle(struct dhcp_opt *opt, unsigned char *popt, int optlen)
+{
+ IPaddr_t ip;
+
+ ip = net_read_ip(popt);
+ setenv_ip(opt->barebox_var_name, ip);
+}
+
+static void env_str_handle(struct dhcp_opt *opt, unsigned char *popt, int optlen)
+{
+ char str[256];
+
+ memcpy(str, popt, optlen);
+ str[optlen] = 0;
+ setenv(opt->barebox_var_name, str);
+}
+
+static void copy_uint32_handle(struct dhcp_opt *opt, unsigned char *popt, int optlen)
+{
+ net_copy_uint32(opt->data, (uint32_t *)popt);
+};
+
+static void copy_ip_handle(struct dhcp_opt *opt, unsigned char *popt, int optlen)
+{
+ net_copy_ip(opt->data, popt);
+};
+
+static void bootfile_vendorex_handle(struct dhcp_opt *opt, unsigned char *popt, int optlen)
+{
+ if (opt->bp->bp_file[0] != '\0')
+ return;
+
+ /*
+ * only use vendor boot file if we didn't
+ * receive a boot file in the main non-vendor
+ * part of the packet - god only knows why
+ * some vendors chose not to use this perfectly
+ * good spot to store the boot file (join on
+ * Tru64 Unix) it seems mind bogglingly crazy
+ * to me
+ */
+ pr_warn("*** WARNING: using vendor optional boot file\n");
+
+ /*
+ * I can't use dhcp_vendorex_proc here because I need
+ * to write into the bootp packet - even then I had to
+ * pass the bootp packet pointer into here as the
+ * second arg
+ */
+ env_str_handle(opt, popt, optlen);
+}
+
+struct dhcp_opt dhcp_options[] = {
+ {
+ .option = 1,
+ .handle = netmask_handle,
+ }, {
+ .option = 3,
+ .handle = gateway_handle,
+ }, {
+ .option = 6,
+ .handle = env_ip_handle,
+ .barebox_var_name = "nameserver",
+ }, {
+ .option = 12,
+ .handle = env_str_handle,
+ .barebox_var_name = "hostname",
+ }, {
+ .option = 15,
+ .handle = env_str_handle,
+ .barebox_var_name = "domainname",
+ }, {
+ .option = 17,
+ .handle = env_str_handle,
+ .barebox_var_name = "rootpath",
+ }, {
+ .option = 51,
+ .handle = copy_uint32_handle,
+ .data = &dhcp_leasetime,
+ }, {
+ .option = 54,
+ .handle = copy_ip_handle,
+ .data = &net_dhcp_server_ip,
+ .optional = true,
+ }, {
+ .option = 67,
+ .handle = bootfile_vendorex_handle,
+ .barebox_var_name = "bootfile",
+ },
+};
+
static int bootp_check_packet(unsigned char *pkt, unsigned src, unsigned len)
{
struct bootp *bp = (struct bootp *) pkt;
@@ -131,6 +249,7 @@ static void bootp_copy_net_params(struct bootp *bp)
static int dhcp_extended (u8 *e, int message_type, IPaddr_t ServerID,
IPaddr_t RequestedIP, char *vendor_id)
{
+ int i;
u8 *start = e;
u8 *cnt;
int vendor_id_len = vendor_id ? strlen(vendor_id) : 0;
@@ -181,18 +300,13 @@ static int dhcp_extended (u8 *e, int message_type, IPaddr_t ServerID,
*e++ = 55; /* Parameter Request List */
cnt = e++; /* Pointer to count of requested items */
*cnt = 0;
- *e++ = 1; /* Subnet Mask */
- *cnt += 1;
- *e++ = 3; /* Router Option */
- *cnt += 1;
- *e++ = 6; /* DNS Server(s) */
- *cnt += 1;
- *e++ = 12; /* Hostname */
- *cnt += 1;
- *e++ = 15; /* domain name */
- *cnt += 1;
- *e++ = 17; /* Boot path */
- *cnt += 1;
+
+ for (i = 0; i < ARRAY_SIZE(dhcp_options); i++) {
+ if (dhcp_options[i].optional)
+ continue;
+ *e++ = dhcp_options[i].option;
+ *cnt += 1;
+ }
*e++ = 255; /* End of the list */
/* Pad to minimal length */
@@ -246,89 +360,40 @@ static int bootp_request(void)
return ret;
}
+static int dhcp_options_handle(unsigned char option, unsigned char *popt,
+ int optlen, struct bootp *bp)
+{
+ int i;
+ struct dhcp_opt *opt;
+
+ for (i = 0; i < ARRAY_SIZE(dhcp_options); i++) {
+ opt = &dhcp_options[i];
+ if (opt->option == option) {
+ opt->bp = bp;
+ opt->handle(opt, popt, optlen);
+ goto end;
+ }
+ }
+
+end:
+ return i;
+}
+
static void dhcp_options_process(unsigned char *popt, struct bootp *bp)
{
unsigned char *end = popt + sizeof(*bp) + OPT_SIZE;
int oplen;
- IPaddr_t ip;
- char str[256];
+ unsigned char option;
+ int i;
while (popt < end && *popt != 0xff) {
oplen = *(popt + 1);
- switch (*popt) {
- case 1:
- ip = net_read_ip(popt + 2);
- net_set_netmask(ip);
- break;
- case 3:
- ip = net_read_ip(popt + 2);
- net_set_gateway(ip);
- break;
- case 6:
- ip = net_read_ip(popt + 2);
- setenv_ip("nameserver", ip);
- break;
- case 12:
- memcpy(str, popt + 2, oplen);
- str[oplen] = 0;
- setenv("hostname", str);
- break;
- case 15:
- memcpy(str, popt + 2, oplen);
- str[oplen] = 0;
- setenv("domainname", str);
- break;
- case 17:
- memcpy(str, popt + 2, oplen);
- str[oplen] = 0;
- setenv("rootpath", str);
- break;
- case 51:
- net_copy_uint32 (&dhcp_leasetime, (uint32_t *)(popt + 2));
- break;
- case 53: /* Ignore Message Type Option */
- break;
- case 54:
- net_copy_ip(&net_dhcp_server_ip, (popt + 2));
- break;
- case 58: /* Ignore Renewal Time Option */
- break;
- case 59: /* Ignore Rebinding Time Option */
- break;
- case 66: /* Ignore TFTP server name */
- break;
- case 67: /* vendor opt bootfile */
- /*
- * I can't use dhcp_vendorex_proc here because I need
- * to write into the bootp packet - even then I had to
- * pass the bootp packet pointer into here as the
- * second arg
- */
- memcpy(str, popt + 2, oplen);
- str[oplen] = 0;
- if (bp->bp_file[0] == '\0') {
- /*
- * only use vendor boot file if we didn't
- * receive a boot file in the main non-vendor
- * part of the packet - god only knows why
- * some vendors chose not to use this perfectly
- * good spot to store the boot file (join on
- * Tru64 Unix) it seems mind bogglingly crazy
- * to me
- */
- printf("*** WARNING: using vendor "
- "optional boot file\n");
- setenv("bootfile", str);
- }
- break;
- default:
-#ifdef CONFIG_BOOTP_VENDOREX
- if (dhcp_vendorex_proc (popt))
- break;
-#endif
- debug("*** Unhandled DHCP Option in OFFER/ACK: %d\n", *popt);
- break;
- }
+ option = *popt;
+
+ i = dhcp_options_handle(option, popt + 2, oplen, bp);
+ if (i == ARRAY_SIZE(dhcp_options))
+ debug("*** Unhandled DHCP Option in OFFER/ACK: %d\n", option);
+
popt += oplen + 2; /* Process next option */
}
}
--
1.7.9.1
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