From 2bf5f3ad1ce6d386938c39d1569f2635300eca6e Mon Sep 17 00:00:00 2001 From: Steven Barth Date: Fri, 10 Apr 2015 13:19:44 +0200 Subject: [PATCH] Pass ICMP configuration to user-space instead of directly applying it --- README | 7 ++++-- src/odhcp6c.h | 5 +++++ src/ra.c | 61 ++++++++++++++++++++++++++++++--------------------- src/script.c | 14 ++++++++++++ 4 files changed, 60 insertions(+), 27 deletions(-) diff --git a/README b/README index 8c66ffa..9b56b20 100644 --- a/README +++ b/README @@ -29,8 +29,7 @@ especially routers. It compiles to only about 35 KB (-Os -s). h) Configurable SOL_MAX_RT i) DS-Lite AFTR-Name Option j) Softwire address and port mapped clients (MAP, LW4over6) - k) Prefix Class (experimental) - l) CER-ID (experimental) + j) CER-ID (experimental) 4. Support for requesting and parsing Router Advertisements a) parsing of prefixes, routes, MTU and RDNSS options @@ -78,5 +77,9 @@ Environment: * RA_ROUTES A space-separated list of routes from the RA Format:
/,gateway,valid,metric * RA_DNS A space-separated list of recursive DNS servers from the RA +* RA_HOPLIMIT Highest hop-limit received in RAs +* RA_MTU MTU-value received in RA +* RA_REACHABLE ND Reachability time +* RA_RETRANSMIT ND Retransmit time * AFTR The DS-Lite AFTR domain name * MAPE / MAPT / LW4O6 Softwire rules for MAPE, MAPT and LW4O6 diff --git a/src/odhcp6c.h b/src/odhcp6c.h index 3e2713e..ff5b9e4 100644 --- a/src/odhcp6c.h +++ b/src/odhcp6c.h @@ -319,6 +319,11 @@ int init_rtnetlink(void); int set_rtnetlink_addr(int ifindex, const struct in6_addr *addr, uint32_t pref, uint32_t valid); +int ra_conf_hoplimit(int newvalue); +int ra_conf_mtu(int newvalue); +int ra_conf_reachable(int newvalue); +int ra_conf_retransmit(int newvalue); + int script_init(const char *path, const char *ifname); ssize_t script_unhexlify(uint8_t *dst, size_t len, const char *src); void script_call(const char *status); diff --git a/src/ra.c b/src/ra.c index 09d5c1d..04764c7 100644 --- a/src/ra.c +++ b/src/ra.c @@ -165,19 +165,6 @@ static int16_t pref_to_priority(uint8_t flags) } -static int update_proc(const char *sect, const char *opt, uint32_t value) -{ - char buf[64]; - snprintf(buf, sizeof(buf), "/proc/sys/net/ipv6/%s/%s/%s", sect, if_name, opt); - - int fd = open(buf, O_WRONLY); - int ret = write(fd, buf, snprintf(buf, sizeof(buf), "%u", value)); - close(fd); - - return ret; -} - - bool ra_link_up(void) { static bool firstcall = true; @@ -249,6 +236,38 @@ static bool ra_icmpv6_valid(struct sockaddr_in6 *source, int hlim, uint8_t *data return opt == end; } +int ra_conf_hoplimit(int newvalue) +{ + static int value = 0; + if (newvalue > value) + value = newvalue; + return value; +} + +int ra_conf_mtu(int newvalue) +{ + static int value = 0; + if (newvalue >= 1280 && newvalue <= 65535) + value = newvalue; + return value; +} + +int ra_conf_reachable(int newvalue) +{ + static int value = 0; + if (newvalue > 0 && newvalue <= 3600000) + value = newvalue; + return value; +} + +int ra_conf_retransmit(int newvalue) +{ + static int value = 0; + if (newvalue > 0 && newvalue <= 60000) + value = newvalue; + return value; +} + bool ra_process(void) { bool found = false; @@ -324,26 +343,18 @@ bool ra_process(void) changed |= odhcp6c_update_entry(STATE_RA_ROUTE, &entry, 0, true); // Parse hoplimit - if (adv->nd_ra_curhoplimit) - update_proc("conf", "hop_limit", adv->nd_ra_curhoplimit); + ra_conf_hoplimit(adv->nd_ra_curhoplimit); // Parse ND parameters - uint32_t reachable = ntohl(adv->nd_ra_reachable); - if (reachable > 0 && reachable <= 3600000) - update_proc("neigh", "base_reachable_time_ms", reachable); - - uint32_t retransmit = ntohl(adv->nd_ra_retransmit); - if (retransmit > 0 && retransmit <= 60000) - update_proc("neigh", "retrans_time_ms", retransmit); - + ra_conf_reachable(ntohl(adv->nd_ra_reachable)); + ra_conf_retransmit(ntohl(adv->nd_ra_retransmit)); // Evaluate options struct icmpv6_opt *opt; icmpv6_for_each_option(opt, &adv[1], &buf[len]) { if (opt->type == ND_OPT_MTU) { uint32_t *mtu = (uint32_t*)&opt->data[2]; - if (ntohl(*mtu) >= 1280 && ntohl(*mtu) <= 65535) - update_proc("conf", "mtu", ntohl(*mtu)); + ra_conf_mtu(ntohl(*mtu)); } else if (opt->type == ND_OPT_ROUTE_INFORMATION && opt->len <= 3) { entry.router = from.sin6_addr; entry.target = any; diff --git a/src/script.c b/src/script.c index d993277..2c34216 100644 --- a/src/script.c +++ b/src/script.c @@ -184,6 +184,15 @@ static void entry_to_env(const char *name, const void *data, size_t len, enum en } +static void int_to_env(const char *name, int value) +{ + size_t len = 12 + strlen(name); + char *buf = realloc(NULL, len); + snprintf(buf, len, "%s=%d", name, value); + putenv(buf); +} + + static void s46_to_env_portparams(const uint8_t *data, size_t len, FILE *fp) { uint8_t *odata; @@ -366,6 +375,11 @@ void script_call(const char *status) entry_to_env("RA_ROUTES", ra_route, ra_route_len, ENTRY_ROUTE); entry_to_env("RA_DNS", ra_dns, ra_dns_len, ENTRY_HOST); + int_to_env("RA_HOPLIMIT", ra_conf_hoplimit(0)); + int_to_env("RA_MTU", ra_conf_mtu(0)); + int_to_env("RA_REACHABLE", ra_conf_reachable(0)); + int_to_env("RA_RETRANSMIT", ra_conf_retransmit(0)); + char *buf = malloc(10 + passthru_len * 2); strncpy(buf, "PASSTHRU=", 10); script_hexlify(&buf[9], passthru, passthru_len); -- 2.39.5