this repo has no description
Initial net.route sysctl implementation
Only supports IPv4 right now
+233
+1
src/kernel/emulation/linux/CMakeLists.txt
+1
src/kernel/emulation/linux/CMakeLists.txt
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src/kernel/emulation/linux/misc/sysctl.c
+2
src/kernel/emulation/linux/misc/sysctl.c
···
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#include "sysctl_kern.h"
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#include "sysctl_machdep.h"
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#include "sysctl_sysctl.h"
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#include "sysctl_net.h"
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extern char *strchr(const char *s, int c);
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extern int strncmp(const char *s1, const char *s2, __SIZE_TYPE__ n);
···
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{ .oid = CTL_KERN, .type = CTLTYPE_NODE, .exttype = "", .name = "kern", .subctls = sysctls_kern },
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{ .oid = CTL_MACHDEP, .type = CTLTYPE_NODE, .exttype = "", .name = "machdep", .subctls = sysctls_machdep },
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{ .oid = _CTL_SYSCTL, .type = CTLTYPE_NODE, .exttype = "", .name = "sysctl", .subctls = sysctls_sysctl },
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{ .oid = CTL_NET, .type = CTLTYPE_NODE, .exttype = "", .name = "net", .subctls = sysctls_net },
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{ .oid = -1 }, /* terminating entry */
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};
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src/kernel/emulation/linux/misc/sysctl_net.c
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src/kernel/emulation/linux/misc/sysctl_net.c
···
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#include "sysctl_net.h"
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#include "../network/socket.h"
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#include "../network/duct.h"
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#include "../ioctl/ioctl.h"
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#include "../unistd/close.h"
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#include <sys/errno.h>
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#include <net/route.h>
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#include <sys/socket.h>
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#include <net/if.h>
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#include <net/if_dl.h>
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#include <netinet/in.h>
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extern void* memset(void* destination, int value, size_t length);
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extern void* memcpy(void* destination, const void* source, size_t n);
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extern size_t strnlen(const char* string, size_t max_length);
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extern char* strncpy(char* destination, const char* source, size_t length);
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extern size_t strlcpy(char* destination, const char* source, size_t size);
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static sysctl_handler(handle_route);
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static int do_iflist(void* old, unsigned long* oldlen);
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#define LINUX_SIOCGIFCONF 0x8912
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#define LINUX_SIOCGIFHWADDR 0x8927
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#define LINUX_SIOCGIFBRDADDR 0x8919
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#define LINUX_SIOCGIFNETMASK 0x891b
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#define LINUX_IFNAMSIZ 16
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#define MAC_LENGTH 6
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struct linux_sockaddr {
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unsigned short sa_family;
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char sa_data[14];
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};
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struct linux_ifmap {
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unsigned long mem_start;
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unsigned long mem_end;
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unsigned short base_addr;
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unsigned char irq;
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unsigned char dma;
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unsigned char port;
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};
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struct linux_ifreq {
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char lifr_name[LINUX_IFNAMSIZ];
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union {
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struct linux_sockaddr lifr_addr;
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struct linux_sockaddr lifr_dstaddr;
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struct linux_sockaddr lifr_broadaddr;
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struct linux_sockaddr lifr_netmask;
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struct linux_sockaddr lifr_hwaddr;
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short lifr_flags;
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int lifr_ifindex;
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int lifr_metric;
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int lifr_mtu;
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struct linux_ifmap lifr_map;
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char lifr_slave[LINUX_IFNAMSIZ];
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char lifr_newname[LINUX_IFNAMSIZ];
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char* lifr_data;
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};
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};
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// arbitrary number; only exists to avoid blowing up the stack
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#define IFC_MAX_INTERFACES 5
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struct linux_ifconf {
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int lifc_len;
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union {
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char* lifc_buf;
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struct linux_ifreq* lifc_req;
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};
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};
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enum {
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_NET_ROUTE = 17,
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};
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enum {
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_NET_RT_IFLIST = 3,
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};
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const struct known_sysctl sysctls_net[] = {
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// technically a CTLTYPE_NODE in XNU, but for us that means that it has children and isn't a variable in and of itself.
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// the actual value doesn't really matter as long as it's not CTLTYPE_NODE
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{ .oid = _NET_ROUTE, .type = CTLTYPE_OPAQUE, .exttype = "", .name = "route", .handler = handle_route },
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{ .oid = -1 },
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};
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static unsigned long round_up_sizeof_u32(unsigned long number) {
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return (number + (sizeof(uint32_t) - 1)) & ~(sizeof(uint32_t) - 1);
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};
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static int do_iflist(void* old, unsigned long* oldlen) {
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// we only do IPv4 addresses for now
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int tmp_sock;
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char buf[IFC_MAX_INTERFACES * sizeof(struct linux_ifreq)];
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struct linux_ifconf lifc = {
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.lifc_len = sizeof(buf),
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.lifc_buf = buf,
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};
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int status = 0;
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char* old_ptr = old;
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unsigned long total_len = 0;
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if ((status = tmp_sock = sys_socket(AF_INET, SOCK_DGRAM, 0)) < 0)
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goto out;
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if ((status = __real_ioctl(tmp_sock, LINUX_SIOCGIFCONF, &lifc)) < 0)
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goto out;
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for (int i = 0; i < lifc.lifc_len; i += sizeof(struct linux_ifreq)) {
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struct linux_ifreq* curr = &lifc.lifc_req[i / sizeof(struct linux_ifreq)];
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size_t name_len = strnlen(curr->lifr_name, sizeof(curr->lifr_name));
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size_t additional_sockaddr_len = name_len + MAC_LENGTH;
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additional_sockaddr_len = (additional_sockaddr_len <= sizeof(((struct sockaddr_dl*)NULL)->sdl_data)) ? 0 : (additional_sockaddr_len - sizeof(((struct sockaddr_dl*)NULL)->sdl_data));
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size_t ifm_length = sizeof(struct if_msghdr) + round_up_sizeof_u32(sizeof(struct sockaddr_dl) + additional_sockaddr_len);
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size_t ifam_length = sizeof(struct ifa_msghdr) + round_up_sizeof_u32(sizeof(struct sockaddr)) * 3;
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// technically not correct; SIOCGIFCONF could return the same interfaces in a different order on each call
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// but this is enough for our purposes
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size_t iface_idx = (i / sizeof(struct linux_ifreq)) + 1;
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if (old && *oldlen >= total_len + ifm_length) {
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struct if_msghdr* ifm = (void*)old_ptr;
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struct sockaddr_dl* dl = (void*)(old_ptr + sizeof(struct if_msghdr));
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struct linux_ifreq tmp;
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memset(old_ptr, 0, ifm_length);
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ifm->ifm_msglen = ifm_length;
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ifm->ifm_index = iface_idx;
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ifm->ifm_type = RTM_IFINFO;
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ifm->ifm_version = RTM_VERSION;
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ifm->ifm_addrs = RTA_IFP;
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dl->sdl_len = sizeof(struct sockaddr_dl) + additional_sockaddr_len;
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dl->sdl_family = AF_LINK;
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dl->sdl_index = ifm->ifm_index;
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/* dl->sdl_type = 0; */ // TODO: determine this somehow
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dl->sdl_nlen = name_len;
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dl->sdl_alen = MAC_LENGTH;
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dl->sdl_slen = 0; // ???
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memcpy(dl->sdl_data, curr->lifr_name, name_len);
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// grab the MAC
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memcpy(tmp.lifr_name, curr->lifr_name, sizeof(curr->lifr_name));
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if ((status = __real_ioctl(tmp_sock, LINUX_SIOCGIFHWADDR, &tmp)) < 0)
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goto out;
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memcpy(LLADDR(dl), tmp.lifr_hwaddr.sa_data, MAC_LENGTH);
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old_ptr += ifm_length;
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}
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total_len += ifm_length;
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if (old && *oldlen >= total_len + ifam_length) {
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struct ifa_msghdr* ifam = (void*)old_ptr;
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struct sockaddr* netmask = (void*)(old_ptr + sizeof(struct ifa_msghdr));
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struct sockaddr* ip_addr = (void*)(old_ptr + sizeof(struct ifa_msghdr) + round_up_sizeof_u32(sizeof(struct sockaddr)));
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struct sockaddr* broad_addr = (void*)(old_ptr + sizeof(struct ifa_msghdr) + round_up_sizeof_u32(sizeof(struct sockaddr)) * 2);
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struct linux_ifreq tmp;
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memset(old_ptr, 0, ifam_length);
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ifam->ifam_msglen = ifam_length;
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ifam->ifam_index = iface_idx;
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ifam->ifam_type = RTM_NEWADDR;
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ifam->ifam_version = RTM_VERSION;
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ifam->ifam_addrs = RTA_NETMASK | RTA_IFA | RTA_BRD;
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sockaddr_fixup_from_linux((struct sockaddr_fixup*)ip_addr, &curr->lifr_addr, sizeof(struct linux_sockaddr));
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memcpy(tmp.lifr_name, curr->lifr_name, sizeof(curr->lifr_name));
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// get the netmask
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if ((status = __real_ioctl(tmp_sock, LINUX_SIOCGIFNETMASK, &tmp)) < 0)
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goto out;
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sockaddr_fixup_from_linux((struct sockaddr_fixup*)netmask, &tmp.lifr_netmask, sizeof(struct linux_sockaddr));
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// get the broadcast address
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if ((status = __real_ioctl(tmp_sock, LINUX_SIOCGIFBRDADDR, &tmp)) < 0)
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goto out;
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sockaddr_fixup_from_linux((struct sockaddr_fixup*)broad_addr, &tmp.lifr_broadaddr, sizeof(struct linux_sockaddr));
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old_ptr += ifam_length;
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}
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total_len += ifam_length;
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}
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// we succeeded if we got here
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status = 0;
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out:
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if (tmp_sock >= 0) {
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// ignore errors while closing
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close_internal(tmp_sock);
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}
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*oldlen = total_len;
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return status;
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};
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static sysctl_handler(handle_route) {
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int status = 0;
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if (nlen != 6) {
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status = -EINVAL;
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goto out;
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}
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// name[4] is the desired operation
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switch (name[4]) {
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case _NET_RT_IFLIST:
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status = do_iflist(old, oldlen);
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break;
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default:
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status = -EINVAL;
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goto out;
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}
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out:
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return status;
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};