From: Daniel Starke <daniel.starke@xxxxxxxxxxx> n_gsm is based on the 3GPP 07.010 and its newer version is the 3GPP 27.010. See https://portal.3gpp.org/desktopmodules/Specifications/SpecificationDetails.aspx?specificationId=1516 The changes from 07.010 to 27.010 are non-functional. Therefore, I refer to the newer 27.010 here. Chapter 5.4.6.3.1 describes the encoding of the parameter negotiation messages. Add the parameters used there to 'gsm_mux' and 'gsm_dlci' and initialize both according to the value ranges and recommended defaults defined in chapter 5.7. Replace the use of the DLC default values from the 'gsm_mux' fields with the DLC specific values from the 'gsm_dlci' fields where applicable. Signed-off-by: Daniel Starke <daniel.starke@xxxxxxxxxxx> --- drivers/tty/n_gsm.c | 58 +++++++++++++++++++++++++++++++++++---------- 1 file changed, 45 insertions(+), 13 deletions(-) v1 -> v2: Incorporated review comments. Changed type of t3 in gsm_mux to unsigned int. Link: https://lore.kernel.org/all/4519259-1e70-351c-756c-57c1e665e94@xxxxxxxxxxxxxxx/ diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c index 570c40a3d78f..c217013b3e16 100644 --- a/drivers/tty/n_gsm.c +++ b/drivers/tty/n_gsm.c @@ -40,6 +40,7 @@ #include <linux/tty.h> #include <linux/ctype.h> #include <linux/mm.h> +#include <linux/math.h> #include <linux/string.h> #include <linux/slab.h> #include <linux/poll.h> @@ -75,7 +76,12 @@ module_param(debug, int, 0600); #define T1 10 /* 100mS */ #define T2 34 /* 333mS */ +#define T3 10 /* 10s */ #define N2 3 /* Retry 3 times */ +#define K 2 /* outstanding I frames */ + +#define MAX_T3 255 /* In seconds. */ +#define MAX_WINDOW_SIZE 7 /* Limit of K in error recovery mode. */ /* Use long timers for testing at low speed with debug on */ #ifdef DEBUG_TIMING @@ -160,7 +166,12 @@ struct gsm_dlci { int prev_adaption; u32 modem_rx; /* Our incoming virtual modem lines */ u32 modem_tx; /* Our outgoing modem lines */ + unsigned int mtu; bool dead; /* Refuse re-open */ + /* Configuration */ + u8 prio; /* Priority */ + u8 ftype; /* Frame type */ + u8 k; /* Window size */ /* Flow control */ bool throttled; /* Private copy of throttle state */ bool constipated; /* Throttle status for outgoing */ @@ -283,7 +294,9 @@ struct gsm_mux { int adaption; /* 1 or 2 supported */ u8 ftype; /* UI or UIH */ int t1, t2; /* Timers in 1/100th of a sec */ + unsigned int t3; /* Power wake-up timer in seconds. */ int n2; /* Retry count */ + u8 k; /* Window size */ /* Statistics (not currently exposed) */ unsigned long bad_fcs; @@ -1075,12 +1088,12 @@ static int gsm_dlci_data_output(struct gsm_mux *gsm, struct gsm_dlci *dlci) return 0; /* MTU/MRU count only the data bits but watch adaption mode */ - if ((len + h) > gsm->mtu) - len = gsm->mtu - h; + if ((len + h) > dlci->mtu) + len = dlci->mtu - h; size = len + h; - msg = gsm_data_alloc(gsm, dlci->addr, size, gsm->ftype); + msg = gsm_data_alloc(gsm, dlci->addr, size, dlci->ftype); if (!msg) return -ENOMEM; dp = msg->data; @@ -1144,19 +1157,19 @@ static int gsm_dlci_data_output_framed(struct gsm_mux *gsm, len = dlci->skb->len + overhead; /* MTU/MRU count only the data bits */ - if (len > gsm->mtu) { + if (len > dlci->mtu) { if (dlci->adaption == 3) { /* Over long frame, bin it */ dev_kfree_skb_any(dlci->skb); dlci->skb = NULL; return 0; } - len = gsm->mtu; + len = dlci->mtu; } else last = 1; size = len + overhead; - msg = gsm_data_alloc(gsm, dlci->addr, size, gsm->ftype); + msg = gsm_data_alloc(gsm, dlci->addr, size, dlci->ftype); if (msg == NULL) { skb_queue_tail(&dlci->skb_list, dlci->skb); dlci->skb = NULL; @@ -1213,7 +1226,7 @@ static int gsm_dlci_modem_output(struct gsm_mux *gsm, struct gsm_dlci *dlci, return -EINVAL; } - msg = gsm_data_alloc(gsm, dlci->addr, size, gsm->ftype); + msg = gsm_data_alloc(gsm, dlci->addr, size, dlci->ftype); if (!msg) { pr_err("%s: gsm_data_alloc error", __func__); return -ENOMEM; @@ -1338,8 +1351,9 @@ static void gsm_dlci_data_kick(struct gsm_dlci *dlci) static int gsm_control_command(struct gsm_mux *gsm, int cmd, const u8 *data, int dlen) { - struct gsm_msg *msg = gsm_data_alloc(gsm, 0, dlen + 2, gsm->ftype); + struct gsm_msg *msg; + msg = gsm_data_alloc(gsm, 0, dlen + 2, gsm->dlci[0]->ftype); if (msg == NULL) return -ENOMEM; @@ -1365,7 +1379,8 @@ static void gsm_control_reply(struct gsm_mux *gsm, int cmd, const u8 *data, int dlen) { struct gsm_msg *msg; - msg = gsm_data_alloc(gsm, 0, dlen + 2, gsm->ftype); + + msg = gsm_data_alloc(gsm, 0, dlen + 2, gsm->dlci[0]->ftype); if (msg == NULL) return; msg->data[0] = (cmd & 0xFE) << 1 | EA; /* Clear C/R */ @@ -2075,6 +2090,13 @@ static struct gsm_dlci *gsm_dlci_alloc(struct gsm_mux *gsm, int addr) dlci->gsm = gsm; dlci->addr = addr; dlci->adaption = gsm->adaption; + dlci->mtu = gsm->mtu; + if (addr == 0) + dlci->prio = 0; + else + dlci->prio = roundup(addr + 1, 8) - 1; + dlci->ftype = gsm->ftype; + dlci->k = gsm->k; dlci->state = DLCI_CLOSED; if (addr) { dlci->data = gsm_dlci_data; @@ -2650,7 +2672,9 @@ static struct gsm_mux *gsm_alloc_mux(void) gsm->t1 = T1; gsm->t2 = T2; + gsm->t3 = T3; gsm->n2 = N2; + gsm->k = K; gsm->ftype = UIH; gsm->adaption = 1; gsm->encoding = GSM_ADV_OPT; @@ -2691,7 +2715,7 @@ static void gsm_copy_config_values(struct gsm_mux *gsm, c->initiator = gsm->initiator; c->t1 = gsm->t1; c->t2 = gsm->t2; - c->t3 = 0; /* Not supported */ + c->t3 = gsm->t3; c->n2 = gsm->n2; if (gsm->ftype == UIH) c->i = 1; @@ -2700,7 +2724,7 @@ static void gsm_copy_config_values(struct gsm_mux *gsm, pr_debug("Ftype %d i %d\n", gsm->ftype, c->i); c->mru = gsm->mru; c->mtu = gsm->mtu; - c->k = 0; + c->k = gsm->k; } static int gsm_config(struct gsm_mux *gsm, struct gsm_config *c) @@ -2717,12 +2741,16 @@ static int gsm_config(struct gsm_mux *gsm, struct gsm_config *c) return -EINVAL; if (c->mru > MAX_MRU || c->mtu > MAX_MTU) return -EINVAL; + if (c->t3 > MAX_T3) + return -EINVAL; if (c->n2 > 255) return -EINVAL; if (c->encapsulation > 1) /* Basic, advanced, no I */ return -EINVAL; if (c->initiator > 1) return -EINVAL; + if (c->k > MAX_WINDOW_SIZE) + return -EINVAL; if (c->i == 0 || c->i > 2) /* UIH and UI only */ return -EINVAL; /* @@ -2770,6 +2798,10 @@ static int gsm_config(struct gsm_mux *gsm, struct gsm_config *c) gsm->t1 = c->t1; if (c->t2) gsm->t2 = c->t2; + if (c->t3) + gsm->t3 = c->t3; + if (c->k) + gsm->k = c->k; /* * FIXME: We need to separate activation/deactivation from adding @@ -3298,9 +3330,9 @@ static int gsm_create_network(struct gsm_dlci *dlci, struct gsm_netconfig *nc) pr_err("alloc_netdev failed\n"); return -ENOMEM; } - net->mtu = dlci->gsm->mtu; + net->mtu = dlci->mtu; net->min_mtu = MIN_MTU; - net->max_mtu = dlci->gsm->mtu; + net->max_mtu = dlci->mtu; mux_net = netdev_priv(net); mux_net->dlci = dlci; kref_init(&mux_net->ref); -- 2.34.1
